Mercury 2 Stroke V6, 60mph for $500, HOT & WET

Welcome Back, HUGE EPISODE with a lot of content, Cheers!
If you are new here, please check out the entire series to learn more about this $500 Cee Bee Avenger project boat we picked up a few weeks ago with a 150hp Mercury Black Max XR2. In this episode I'll show you how to fix your water pressure gauge, we run it without any thermostats, we check the water pickups while on plane, POP SOME BOAT WHEELIES, go for another test run WITH brand new thermostats and do MORE WHEELIES, check the head temps with friggin lasers, I solve the mystery of the 2 bolt (old style) poppet valve, I show you how to verify your oil pump is working on the injection system, we go for another rip and start taking on water/sinking, and we still can't figure out why this thing is overheating and beeping at us constantly.
Also, if you are new here, please check out this entire series; there was an amazing response to the first episode in this series that covers the design and development history for the Mercury 2 Stroke V6 Outboard( • Mercury 2 Stroke V6 Hi... ).
LINKS (Costs you nothing, I make like 50 cents)
1/8 Nylon Water Pressure Tubing: amzn.to/3qbIdZ7
Sarah's Swimsuit: amzn.to/3ST625m
Merc V6 Thermostats: amzn.to/3RjesBN
Merc V6 Poppet Valve Kit (Wrong Diaphragm): amzn.to/3CSQybT
Merc V6 2 Bolt SOFT Poppet Diaphragm: amzn.to/3cMlwHS
IR Laser Hotness Detector: amzn.to/3q7rrKS
#MercMonday #MercuryOutboards #mercuryracing

[@DJHale68]

There are two areas I'd like you to check in the block for blockages. First pull the exhaust cover and divider plate. You'll then see 8 holes drilled thru the block from the exhaust plate flange into the water chest around the cylinders. I think they're 1/4 inch holes and are drilled 4 on the port side and 4 on the stbd side. Make certain these holes are fully open. Secondly - At the top of the exhaust cover there's a rectangular opening made by a core ( about 1 1/2 inches by 3/4 inches) which goes into the block several inches where it meets the core coming up from the bottom of the block. When the block is die-cast there is always some flash across where these two cores meet. When the operator is de-flashing the block casting he has to knock out that flash or water from the pump can't get into the exhaust cover. It could be that that flash was not cleaned out properly and is only allowing a small amount of water thru. Very unlikely but - what the hey - take look while you've got the cover off.

[@Sauerbrew777]

Even with the engine issues, $500 boat is a steal! One of those sunset cruises alone is worth at least $500 in memories! Hope you're able to get the issues fixed cheaply and soon!

[@michaelmurrietta2263]

Great buy I had an xr2 it can put out 170 hp it's not a regular 150 investigate it

[@hartshut]

Pull the temperature sending unit out of the engine. Heat a pan of water up to 150 degrees. With the sending unit wire hooked up and grounded and the key on, drop the sending unit into the hot water. Check the temperature gauge to see if it shows over heating. If it does then either the sending unit or the gauge is bad. If it doesn’t, check for bad ground wires or ground connectors.

[@pgnandt]

The gauge does not display temperature but can tell you something. Simple to test like you say. Take the temp of the water then look at the gauge. Overheat horn can be tested the same way. I also suggested this a few weeks ago.

[@mjodr]

I like that test, but I think this motor is still actually getting hot way too fast.

[@ADDvanced]

Good idea, I will do this this week

[@heesanoice7637]

When you push the key in , it engages the electric choke. That’s why it starts better by pushing in the key on cold starts.

[@richardgregory5815]

Rapid beeping is oil warning signal constant tone is heat warning as others have commented. The plastic oil pump drive gear may be the the next check

[@artlife6210]

you guys are showing people how much there is to consider when overheating or having troubles...I found in mine that the water jackets and the heads had chunks of sand and salt/corrosion clogging the passages, scraped them out and my temps stayed perfect. Order some water jacket gaskets and I bet youll find theres a obstruction somewhere in there even though its still pissing good.🙂

[@caveone-365]

This is what I was going to mention. Might not be a bad idea to check the coolant passages in the block/ heads. Chunks/ deposits can cause enough of a restriction to cause all kinds of erratic temps and hot spots which are no good obviously. I know its a bit of work to verify and you'll need gaskets but might be the issue. Tearing it down is really the only way to know unfortunately, but something to do in the off season if nothing else. The infrared thermometer was a good call on this. Used them enough on cars, no reason it wouldn't be of use on an outboard. Good times LOL👍😎✌

[@carlosarthurpetry3674]

I said it in the previous episode and will say it again. Pull the headers off. Easy and cheap job. You most likely have some sort of build up on it, not necessarily blocking the water passage, could also be acting as thermal insulation between the metal and the water.

[@ADDvanced]

Headers? Or the rear panel the coils are mounted on? Are those considered headers? Thanks in advance!

[@carlosarthurpetry3674]

@@ADDvanced Sorry, not headers, the heads.

[@carlosarthurpetry3674]

The part where the coils are attached is the exhaust cover. It is not a bad idea checking it as well.

[@charliebailey2359]

Another enjoyable flick. Good times out on the lake with your lady, brings back good memories for me.

[@PottsieVol]

Might be completely unrelated but dad and I cleaned out the oil reservoir and pickup tubes that go from the main oil tank in the boat to the smaller tank inside the motor cover of our 87 model blackmax 150. Sludge had built up over the years and we would get the exact same warning beep because the oil level would get low and the engine would overheat. Now it runs much cooler and no alarms.

[@chrisvarga4338]

Look under the waterpump base in the lower unit for any pieces of the impeller. They usually fall into that area, versus finding them in the exhaust passages as you did. There is a cooling water flow diagram in the service manual. You might trace the cooling water path from the exhaust extension to the exhaust divider and see if any got stuck. I do think your issue is leaking head gaskets, however. Mercs usually run with no more than 15 PSI water pressure at high speed, usually less.

[@darintraver4983]

Great video guys .. it’s great watching u guys working threw the problems right or wrong ur giving it ur best shot and that’s genuine and AWSOME !!!

[@ADDvanced]

Thanks! Learning a lot!

[@TheStephenspann27]

I have the same motor with the same symptoms. I too doubt my sending unit/gauge combo. In one head I have an alarm sensor and In the other head I have the temp sender. My alarm has never gone off but my temp gauge moves just like yours as I go on plane. I’ve done all the fixes you have plus I removed the head covers and the valley cover to check for corrosion and blockages. It was perfect inside. I also found my timing was way off. I fixed that and it helped power but still ran hot according to the gauge.

[@TheStephenspann27]

I have also replaced bad reeds but haven’t done a water test yet

[@mattquail8590]

Your vids are mint please keep doing them!

[@ADDvanced]

Thanks buddy!

[@philiplewis1774]

Looks like you're making some good progress! A couple of things to check out - put the thermostats back in, those are for low speed operation, they need to be there to get the block to the right temp before you put the gas to it. The poppet is for high speed operation, it looks like you've mostly sorted that out, Merc made a lot of running changes so it can take a while to figure the older ones out. If you're getting 12-15 psi around 5000 rpm, the poppet is working the way it should. For your gaskets, get some aviation gasket sealer (merc also makes perfect seal, but AV gasket sealer is basically the same stuff), paint that on the gaskets, it will fill in the gaps and prevent blow out. That the temp is climbing is still a little worrisome, when the water pump went in, you needed to spin the drive shaft clockwise to get the vanes to orient correctly, the other issue would be the manufacturer of the pump kit itself, stick with merc / sierra / quicksilver. The off brands can have the cup separate from the plastic, that can also happen if the vanes didn't get oriented in the right direction. If the vanes are stuck wrong direction in the cup and the cup spins, it will move water like a circulator, but not like a pump, you'll get a working tell tail, and it will cool, just not well. The module could be bad, but I doubt it, if it wasn't working right it would be beeping all the time, its beeping at a specific time, when its getting hot. That bog you experienced was probably caused by the damaged poppet gasket, my guess is you're leaking water into the exhaust chamber, it fills and on the hole shot you've got to blow it all out. That had all the symptoms of excessive back pressure, it feels like fuel, but its not, its a water leak backing up the exhaust. Definitely fix that gasket, its damaged. You can test the theory running on ear muffs, if it runs fine with no bog, but bogs in the water, its back pressure caused by water backing up in the exhaust. You're definitely getting it close to sorting it out, you've got a mix of the complex and the complicated. 🙂 I've run into most of these things on mine as well, the fix usually involves rechecking everything and finding the deviation from what mercury intended. A couple of more adjustments and that beast will be firing a 100 foot rooster tail (with no beeps)! cheers!

[@ADDvanced]

I installed the water pump while spinning it. Watch episode 2 for proof. I installed brand new thermostats. I ordered the correct popper valve it is not damaged. Yesterday I pulled the head and the cooling passages look perfect so I pulled the coils and exhaust plate. Also no blockages. I don’t get it.

[@philiplewis1774]

@@ADDvanced The manual indicates that if the water pressure is normal-high, it could be a one of the outlet water passages is restricted or a steam pocket is forming at the top of the powerhead from a lack of cooling water. Do you have access to a 2.0, 2.4, or 2.5 manual? They show how water cycles through the midsection and powerhead. I've had a number of gasket failures on my older motors, they always ran, but would exhibit odd behaviors when pushed to the top end like what you're seeing. Q - Is the water coming out of the tell tail warm, hot, or really hot? Just thinking along the lines of the journey the water is taking through the system and if its getting interrupted or not.

[@ADDvanced]

@@philiplewis1774 Go check out my latest upload, it's a short. Just found a MAJOR clue as to what has been going on.

[@philiplewis1774]

@@ADDvanced Great Sleuthing! Got some debris in the block I see in that short, that would definitely cause flow problems at the top end. Looking forward to seeing your progress!

[@ADDvanced]

@@philiplewis1774 TRYING to pull the powerhead but it's arguing with me.

[@lafountainmountain3244]

It actually runs to cool without thermos which can cause cold seizing i believe so ur suppose to run them with like washers of a certain size for restricters.

[@pgnandt]

Yes cold seizing is an actual thing. I read that the thermostat controls idling temp and the poppet controls high power settings.

[@Chris-zp6eh]

You two are great! Love the boat!

[@rumnboats7612]

Nice rips! if you want to check if it's oil or heat alarm (it's oil) to eliminate the oil alarm there's another wire from the box a brown one that you have to remove it goes to the other side, just unplugging the wires from the tank and sensor on top of oil pump won't work. Doesn't look like it's overheating to me probably just scaled a little but fine.

[@jeffreyperrault3792]

As a 30+yr.mechanic I think you just have a bad sensor..as a kid growing up on the water one of the first things my dad taught me is."is the engine peeing out water when it's idling".lol checking temps was a great idea,not only do you have good cylinder to cylinder temp.140-150 degrees is NOT overheating. If it got (gets) to 200 that's a problem and it needs to be shut down immediately but again 150 isn't overheating or something to worry about.love your channel this episode is the first I have seen,keep it up! Great job!

[@ADDvanced]

First episode?! Oh man, def go check out the Merc V6 History video, and the SST build. Also the snowmobiles. And the bus. And the 911 stuff. Cheers haha

[@pgnandt]

If you're a 30+ year mechanic you should stick around. Evidently he is going to water test the sender so he can get an actual temperature reading with the gauge he has. WOT temp is unknown. He's backing off and being careful which is a smart thing to do. Regarding his overheat horn. I have read that this is often referred to as a it's too late horn. I'm not sure if he's getting a horn or not. Waiting for the next video.

[@ADDvanced]

@@pgnandt I boiled a pot of water tonight and checked the gauge and sender, and I think they're reading fine. I think I am going to need to pull the powerhead and check the adaptor plate gaskets. Not super cool.

[@pgnandt]

@@ADDvanced Were you able to determine what your running temperature was the other day when you were overheating? Just to be clear you are getting a overheat alarm is this correct?

[@ADDvanced]

@@pgnandt The other day I think idling back to shore cooled it down to quick. I have heard the overheat alarm only after running it real hard for long periods of time. I'm going to pull the heads and exhaust plate tomorrow

[@donniebelcher7214]

Pull lower unit put a bucket under the mid section. Pull thermostat cover back flush through thermostat holes. Then put the hose against the water pipe going up to the motor. Check bucket for rubber chunks. Running whit out thermostats not a good idea i made some restrictive washers for my 88 200. You have to slow the water down to pull the heat out of the metal. When installing water pump use dish soap on the propeller and check to see if the ears on the propeller facing right direction. The proper water pressure at idle is 18 psi. If the people before you ran it hot or low on oil it could have gall marks in the cylinders. That happen to my 89 200. It would run good until going full throttle and then the buzzer would go off. Hope this help Sharah wish my wife want to learn like you do.

[@rickrhodes1110]

Fix the Blue Sleekcraft please!!! That's why I started watching you guys!! My family had a blue boat like tours when I was a little kid!! I loved that boat!! My friends were jealous of that boat!! Please fix it done day !! I knew you're busy but my happiness depends on it!!

[@ADDvanced]

I screwed up this year and got distracted with land, a school bus, and the 911. Blue boat is going to stay wrapped up til next spring. I cannot wait, it's going to be an animal.

[@mariusnerb1142]

Try and replace the old temperature sensor and gauge with a new one. cheap automotive meter temporarily connected to exclude failure of sensor or meter

[@timothychainey4669]

I would also try to backflush the system by any means possible. Could be some old rubber impeller in the water jackets.

[@hydrostream76]

when you have the motor trimmed up and put back down it will be sluggish, taking off Carbureted motor and they like gas some guys move the prime bulb up beside them because of the hassle at start up the water pressure gauge looks like it's working normal awesome video

[@ADDvanced]

I think I might need to bleed the system, removing that line to test the oil injection might have introduced a bubble.

[@bassassin2ohseven584]

May be worth trying to blow compressed air back through the pee hole. Popping off the heads is no big deal either, new gaskets are cheap just to take a look inside. My XR6 150 has around 15 lbs of pressure at idle and depending on where I have the jack plate between 10 and 30 pounds running. I think you've got plenty of pressure.

[@buckrockerm]

My xr6 water pressure steadily climbs as I increase RPMs. Then on wide open throttle it drops about half. Kind of disturbing to me but I am now wondering if this is normal?

[@ADDvanced]

That is probably the poppet opening, Buck!

[@geraldkoth654]

Easy to backflush through the thermostat openings. I would remove the lower unit so you have a wide open channel for the water to flow. Trying to push it through the pump will be very difficult. Just take out one thermostat and stuff a hose nozzle with some rags and then blow it out. Same on the other side. Try with one out and both out on both sides.

[@Mags120fish1]

I have two friends that have had chronic overheating issues they couldn’t figure out. In both cases they ran some sort of a solution through the engine which cleaned out the water passages in the block. In both cases this solved the issue. I believe it was some sort of acidic solution. They both used an electric pump and let the solution run through the block overnight. You might research it. Checking the overheat alarm is also needed. Pulling the heads would tell you a lot about the condition of the water jackets and if they are full of hard water deposits. I see Starbrite makes a product just for this. Just searched YT and there are quite a few videos on descaling. Saw one where a guy was using a bilge pump to run it through the block.

[@mjodr]

Probably a good idea. If there is that white scaley crusty shit in there, then acid is the best thing to dissolve it. The stronger the solution and the longer recirc time the better.

[@pgnandt]

Thermostat and poppet ports looked clean.

[@Mags120fish1]

@@pgnandt yes they did, as they did on both motors I referenced above. Both ran in fresh water only, but in an area where we have a lot of limestone. If all else fails this is where I would go next.

[@pgnandt]

@@Mags120fish1 Yes flushing should be on the list. I would try everything.

[@Mags120fish1]

@@pgnandt yes, might as well. These engines are so expensive these days.

[@marthamcgill5807]

hope you figure it out because our 150 is doing the same thing just not as bad, it was suggested to me that the cross hatching in the cylinder bores are warn out creates more heat, sounds like chasing a tail

[@dynaryda8857]

You guys are hilarious 😂😂

[@ADDvanced]

She's always entertaining :D

[@michaelmurrietta2263]

Take the cap off turn it upside down while running and see if it stops beeping

[@michaelmurrietta2263]

And no motor is to old and guardian was not incorporated into system

[@weilfast]

I know you don't want too, but bin that oil injection/alarm box, and premix= no more broken alarm tone. The plastic worm gear that drives pump, on crankshaft, is a known failure point. On my boats I have a separate alarm under dash, or near throttle control box, for my overheat. Not sure about your boat, as the rigging is a bit older. Your non contact head temps looked good and safe. Maybe you have a bad sender or gauge. Your water pressure does seem high though. I would think 15 to 20 lbs would be more normal. You could try to back flush through thermostat holes in heads to clean water dumps in adapter plate, but alot of times you have to pull power head off of midsection, which requires gaskets, and is a pain in the arse. Most of your water that circulates through block, exits these dumps into midsection. You could also try dumping more water through telltale(s) as a possible fix, achieved by running separate unrestricted hoses off of thermostats, common on hi performance application. Looks like you could raise your engine about 4 inchs. You can get away with plugging the top 3 of eight intake holes on l/u. With a stock merc l/u on most boats your safe to run the propshaft about 3 to 3.5 inchs below the bottom of boat. The higher you mount engine, the more prop you will need. All this headache, is good experience for your sleek craft build.

[@areyes3765]

possibly some old water pump vanes broke off and are blocking water passages to water jackets around the cylinders, might have to pull cylinder covers and take a look

[@davidmclendon7244]

Rob, try dropping the engine all the way down on the transom plate. My 150 Merc was mounted on the transom and had no water cooling issues. Water needs to be draining out of the drivers side of the engine, even at top speed. Also, do you have power trim on your boat ? To reach 60-65 you need to trim the engine out to find the "sweet spot". The boat has a delta bottom 2-3 feet aft of the boat that needs trim on the motor to be effective. Don't over load the back of the boat and you won't get any, or very little, back wash in the transom wert well. Don't give up, you are going in the right direction with your bargain boat.

[@mjodr]

I disagree. That motor is still buried deep. The anti-ventilation plate isn't even above the water at cruise. He could probably go UP a couple inches and still be good.

[@ADDvanced]

No, it's already too low. Yes, I have power trim and I'm using it in all these videos, you don't see a rooster tail because the engine hangs too low. Coast guard plate says 150hp, and it has 150hp, so it's not overloaded... yet

[@506curtis]

I'd say you are chasing a problem that doesn't exist. Time to check your temperature sending unit. wiring and gauge. Super sweet boat though. And them black maxes are bad azz. And also it looks like your motor can be raised up a few inches. You want the anti cavitation plate on your motor hovering just above the water when on plane. You'll gain some speed and your boat will have a lighter handling feel.

[@skinnyguy3184]

I'm so glad I'm not the only one who likes doing wheelies 🤣, as for your problem I am completely lost you have done everything I would have done, the only thing I would be thinking is a blockage..

[@ADDvanced]

Idk what else it could be. Time to order a bunch of gaskets and start unbolting stuff.... :\

[@skinnyguy3184]

@@ADDvanced yep thats the only option left i rekon, plus good video content!!

[@zalmanfans1334]

I was a the lake and I was talking to a guy who's got a boat very similar to this one but it was blue it even had the 150 mercury and in person when he punches it it sounds so good .

[@ADDvanced]

Audi 5 cylinder, V8s with lumpy cams, and Mercury V6s. My favorite noises. Though my 7.3 powerstroke sounds kind of rad too lol

[@artlife6210]

gonna have to take that motor apart, theres a clogged cooling passage somewhere, good luck!

[@mjodr]

That's my best guess. He tried enough things to make me think the same thing. I've seen these merc's taken apart and somebody finds the corroded/clogged water passage and it's amazing what will happen in there or how little it takes to screw it up. Just like all my wrenching, you can keep bolting on parts all day, but eventually you gotta get your hands dirty.

[@thehighwayrunner8881]

Id pull the heads before committing to a rebuild. He can make sure there are no obstructions bolt the heads back on, pull the lower unit, pull the thermostats and back flush with a grden hose through the thermostat openings. If the cylinders are reading around 150. I think it either the sensor, or poor flow at the top of the block. And with water pressure gause reading that high and the location of the pressure pick up point being on to of the block almost has me leaning more to the sensor. The pisser looks to be shooting a good streat and the pressure guage is reading really good.

[@tims6104]

Check for impeller pieces you could try back flushing from the thermostat that old of boat gage could be misreading also with the jack plate on it check pad to prop hight motor may be to high reason for porposing could try lowering it also a whale tale stabilizer may help usually they are a remedy for a poor set up on the motor

[@ADDvanced]

The entire gearcase is under water, it is definitely not too high

[@pgnandt]

@@ADDvanced Yes you are plenty deep. Scratch that off your list.

[@BatByke]

Too high or too low can cause porpoising. Too low, longer moment arm, greater torque lifting bow. Too high, prop cavitates when bow drops, then grabs again. That seems what they were experiencing, motor RPM changing greatly. Too low motor RPM does not change much or at all.

[@markzeleznik4245]

I agree with the temperature sensor comments! Could also be a head gasket or exhaust leak into the cooling system… but hopefully not the motor looks really clean and not corroded!

[@ADDvanced]

I checked the sensor and it appears to be fine. I pulled the heads and the exhaust and I don't see any blockage... maybe fresh headgaskets will solve it???

[@rustycrustytriesstuff]

Do you think you could adapt an automotive type temp gauge to compare it to the gauge you have in the boat? Might also be able to check existing sensors and gauge with an ohm meter if you can find what they should read. Also on the high end it is possible that you have a lean fuel condition. I know a lot of two strokes that I’ve had in the past would run higher temps when lean. Did you guys rebuild the carbs? I can’t remember. Might could try a larger high speed jet in the carbs. Some things to consider. As for back flushing the thermostat you could probably either make a cover plate out of aluminum or plastic that bolts in place of the thermostat with a hose adapter or just wrap the end of your hose with electrical tape until it fits the thermostat hole snuggly.

[@michaelheinsler5441]

Hea Rob you are doing the right things I don’t think you are get hot I think the alarm is the oil😜 you need to check the temp gauge and sending unit to see if there are on the same page the sending unit has a value and the gauge need to match @ full hot or you will be reading hotter then you are. My choice of parts are only Mercury original only don’t by aftermarket 😩

[@ADDvanced]

If I go hard enough for long enough I will get a solid tone.... idk why the oil alarm is going off, I have a feeling the alarm box is being dumb.

[@woosh073]

Awesome video even though you still having issues but for 500 bucks it's still a good deal. Once finished you'll definitely increase your knowledge and that is worth alot more.

[@ADDvanced]

I'm always buying broken stuff; it levels up your skills!

[@Orbacron]

Get camera on water outlet when you are full speed.. It might do some strange anomally. I did have one outboard that wouldn't get good water flow with the shifter inspection plate on, so I took it off. The exhaust backpressure inside the lower drive unit was stopping the water flow at high speeds

[@ADDvanced]

The tell tale? Will do.

[@timothyengland3]

Hey guys,,, the laser thermometer said 145 is degrees,,,, those thermostats are 142,,,,, so I don't think it's over heating,,,, next step is to find a temperature sensor test, or replace sensor and gauge with a known operating one,,,, I'm not 100%, however if sensor is bad it would be sending wrong information to switch box then onto the alarm,,, good luck and welcome to outboards,,, boat stands for belt out another thousand,,,

[@ADDvanced]

Nah I'm going to finish this thing for under $1000, just wait :D I think if i ran it harder and checked the temps before idling back they'd have been a lot hotter.

[@pgnandt]

I don't think it's overheating either. He's not getting a horn last I heard. No steam out of his tell tale. It's unknown what that temp gauge is displaying. Even if there was a temp reading I would not trust a 40 year old thermocouple. 25$ on Amazon you can buy a digital thermocouple thermometer dual-channel. Can measure 2 cylinders at a time. Gorilla tape the t-couple wires wherever you want.

[@owensbama1923]

Mine does that where you went wide open throttle and it didn't Rev up and then it did. Intermittently mine does that I have to just keep working the throttle back and forth a few times and it will go. I haven't figured it out yet.

[@geoffmaule4103]

Cheque all electrical conections especially earth, on the motor and gages as a bad earth will give odd problems and next time clean and pore boiling water over the thermostat to see if good or not as it should open when hot.

[@dj-pizza]

On my alarm issue, after replacing the water pump, the cup had spun. Installed another housing with new cup and solved my problem.

[@ADDvanced]

Was it legit quicksilver or sierra/knockoff kit?

[@dj-pizza]

@@ADDvanced Yeah, knockoff but recheck your water pump after you do everything else and can't resolve the issue.

[@kennethellison2313]

i had the same issue with a 1994 Evinrude 150. it was the automatic oiler. my boat has an alarm diagram. a long beeeeeeep is over heating, a beep, beep, beep is an oil issue. when i was at low RPM's no alarm ( 1000 to 2000 ). the reason was that the pump diaphragm had a crack in it and it only started sucking air when it was under high presser ( full throttle ) . i was going to change the automatic oiler but it was over $400 so i cut the oil alarm wires, capped off the auto oiler and pre-mixed the gas. NO more problems. my water pressure runs very high at high RPM. ( 36 to 40 ). hope this helps.

[@karaDee2363]

After everything you've done, I'm going to say that you've been chasing ghosts and don't really have an overheating issue... I think it's either a bad temperature gauge or sending unit... So replace them both.. 12 PSI water pressure should be fine.. I remember having a similar overheating issue on my mercruiser 350.. drove me nuts for a couple months trying to figure out what the problem was.... After I upgraded all my gauges and sending units... The overheating issue magically went away...

[@pgnandt]

The gauge has no temp readout. I would never trust that.

[@karaDee2363]

@@pgnandt yeah, looks like a cheap gauge... I put autometer pro Comp Marine gauges in mine...

[@michaelmurrietta2263]

You know you can't replace sender from auto parts store they look the same but aren't

[@pgnandt]

@@michaelmurrietta2263 He's going to hot water test the sender. Hopefully he marks the gauge. I'd mark 160, 180 and 200. It'll keep him from buying a new one.

[@michaelmurrietta2263]

Metal heat not water

[@greauxpete]

Start at the pump, then check tstats, and poppets.. I would replace all of these items as a baseline. I would not run without the tstats. This could cause a cold seize of the piston. Piston gets hot, cylinder wall stays cold = cold seize. Tstat temp can be checked with IR thermometer at the center of the tstat housing should be close to tge tstat opening temperature. 15 psi at idle is way high.. If tstats are OK, maybe stuck popett?

[@ADDvanced]

Replaced all that stuff man. Still no change.

[@greauxpete]

@@ADDvanced what is the opening temp of your thermostat? Are you actually overheating? If you are overheating, I would double check the poppet and then check for obstructions in the head, water pipe, etc.

[@redboatlover1976]

Oil sensor shaft alarm possibly it lets u. Know if shaft has disintegrated it just randomly goes bad somes time it is located near throttle linkage on powerhead

[@ADDvanced]

Literally tested the oil pump and it's pumping fine, so that's not where the alarm is coming from.

[@redboatlover1976]

@@ADDvanced next time out just unplug each sensor til alarm goes away then let u know which one is at fault

[@davidmclendon7244]

Rob, OK you replaced all the guts in the cooling system. I wonder if there is corrosion in the water circulation system?? Also there could be a problem with cavitation around the water pickup under acceleration. Try dropping the engine 1 inch to, to hopefully eliminate or reduce cavitation possibilities. Don't give up.

[@thehighwayrunner8881]

His motor is already to far down. With the water pressure he has hes not getting cavatation at the water pickups. Once he gets the temp issue solved he could block the top two holes on each side and rasie the motor. From the video it looks like is cavatation plate is already burried in the water.

[@ADDvanced]

It's so deep right now! Just need to solve the overheating, then it's time to raise it!

[@davidmclendon7244]

Rob, if the over-heating problem is not solved with these simple parts exchanged then the question is. Did the boat spend time in salt water? If so the water jackets might be crusted up with crude, same with not flushing engine after running in shallow fresh water.

[@ADDvanced]

Don’t think so it’s a Midwest boat. No signs of salt water use ever.

[@JaysElectronicTinkerShack]

love thos boat and these v6 are ace does seem like theres some serious water pressure there i reckon u have some blockage inisde the water galeries somewhere u could also have a faulty sensor or gauge

[@30pitchcleaver]

I would leave the cowling off, run it around and check around the block with the temperature gun to see whats up.

[@pgnandt]

Good idea.

[@ES-xc6fk]

Excited to see your new release. Just brought home a 1979 Max 200 that hasn't ran since 2011. Going out shortly to pop the cover and inspect. Would like to get your thoughts on this particular motor. I have sent an email but don't know if you noticed it.

[@darrellswaney1064]

They are really good motors I have a friend that still runs his today

[@ADDvanced]

I got your email, can I share the pics in the next episode?

[@ES-xc6fk]

@@ADDvanced So sorry, just now came across your reply this morning. I am cool with you sharing photos I have shared with you if they help in anyway with things you want to share with everyone. Feel free to email me back anytime if you want to talk, watching your do the fiberglass work on your other sleekcraft does help a lot with getting ready to set up my similar projects. One thing though, really makes me want to clean out my garage so I can work on it at anytime. lol. Thanks again for what you two share.

[@dragbikedemon]

I’m not a boat engine expert, but can you disconnect the hose where the thermostat is?? Maybe verify that water is flowing?? Maybe flush from there??

[@sail4horizon]

I think it's a blown head gasket. At idle it runs fine but when you get on it combustion pressure goes up and blows through the gasket hard into the water jacket. Temp and pressure climb fast when you're on the gas. Can't quite tell but looks like steam from your exhaust when we were looking at the lower unit under throttle. Back at idle it can cool down because the combustion gas doesn't overwhelm the cooling system.

[@greyone40]

Interesting thought. I know it's pretty easy to diagnose in an earthbound engine because it blows out the coolant, but here you wouldn't have that as an indicator.

[@pgnandt]

To check the integrity of the head gasket you would do a 'leakdown' test. Verifies head gasket and rings. This is done with airplane engines annually. Easy peasy.

[@kencraig6526]

Oh and then use copper head gaskets to give a bit more compression

[@gridfreedomquest8613]

your motor jack might need to be raised. it looked like it was too low in the water when you planed out. that will help the porpoising.

[@scottlarsh3119]

Sweet "Great Lakes" shirt in the intro!!!!

[@ADDvanced]

You know it! Florida peeps have cool boats too but winter keeps you from getting super soft

[@SmalltownBassin]

check the ignition for double firing cylinders.

[@Murphyslawfarm]

G'day great video you two

[@bertbaker1112]

Before you fitted the new water pressure gauge, there was a fitting in the top of the block with about 2 ft of thin plastic tubing. Why was there no water spraying out of the open end of that thin plastic tube ?

[@ADDvanced]

I don't know... that's a good question. Found some more clues tonight. Stay tuned....

[@DJHale68]

Maybe it was squirting out but with the cowl on he never saw it!!

[@208miuwu]

You maybe having a double firing meaning one cylinder is getting spark twice. Seen it here on KZbin. You'll have to check the timing in low light or the dark, move the test light all around the flywheel as your checking. Look up Small Town Bassin he had the same problem

[@davessparetime83]

Overheating because of no thermostat only happens in contained water cooling systems like cars have. Being a boat in constant new water going through the motor it should have been very low water temp with no thermostats. Look for coolant blockages in the motor. If the motor was overheating, that pee hole water stream should be scalding hot. Get a Black Whale Tail for the lower unit to get on plane quicker and stay on plane at lower speeds. Also helps stop purposing.

[@pgnandt]

Whale tails are for slow heavy poorly designed boats. This is not that.

[@QiwGaming]

Whats the reason you hook up a small container with fuel when you check the oil injection system instead of just leaving the fuel line in the tank?

[@ADDvanced]

It was premix in the small tank since it’s no longer injecting oil

[@hoodatdare7039]

I HAD A 1955 KG7 SUPER 10 MERK ON A 8 FOOT TINY TITAN 3 POINT HYDRO. AND ONE THINGS FOR SHURE YOU CANT CHOKE THEM ENOUGH WHEN THEY ARE COLD. MINE HAD THE STOCK LOWER GEARCASE. I WAS CLOCKED AT 41 MPH. WISH I HAD A QUIKY LIKE YOU. COULD DO 50 MPH GIVER EH ! ( that means petal to the metal ). P.S. THE MIXING OF THE GAS HAS A LOT OF OIL. AND ITS REALY ABOUT 18 HP.

[@Jellepeire]

Put your hands on the engine? Is it really hot or is the gauge faulty ? Sometimes the block is klogged inside blokking water flow in the right places water always takes the easy way out

[@pgnandt]

I mentioned this before. Pain threshold is around 160 F. When running in the driveway I would always touch the cylinders. Looking for a hot one. Head and cylinder. Just at idle though.

[@stevejackson4136]

You checked the temp on each cylinder with your laser gun and 150-160 was not hot. Are you sure it’s not a bad gauge or sender unit?

[@rumnboats7612]

it's an oil alarm, easily diagnosed by simply listening to the beeps

[@lesabre1972]

Maybe it is too high with the jack plate bringing the water inlet out of the water or just causing water cavitation around the inlets.

[@ADDvanced]

Nope. Covered in another video and confirmed to be buried.

[@thehighwayrunner8881]

Check the wires from the temp sensor, may need to replace the sensor. I think its time to pull the heads and check for excess sand or calcium build up. With the temps of the cylinders being in the 150 range. It almost seems there could be build up on the sensor, or the water at the top of the block is not flowing properly. Make sure the cross over hose from the port head to starboard head is clear flush the hose both directions. Next time you take it out. Right after you run it use your gun to check the heads and then where the temp sensor is mounted.

[@thehighwayrunner8881]

The down on power was probably from premix still in the carb and fuel line then hooking the oil injection back up. The plugs are probably fouling out from the oil. I wouldnt worry about it. Replace the plugs when you pull the heads

[@edwardcote1331]

i just binged all the blue tunnel hull videos.good stuff.i'm curious to see where you mount the gas tank.i keep catching Letterkenny refrences?

[@ADDvanced]

Can confirm! Gas tank is secured behind the seat, not sure what keeps it from moving around. Give yer balls a tug!

[@duramaxklem1491]

The old school snowmobile guys use to just run mixed. If your running up hill they never trusted the factory oil injection.

[@jetirex]

I would replace the sensor just to rule it out. I've been through that goose-chase with an old Jonnyrude and it was the sensor the whole time...

[@ADDvanced]

Probably a good idea

[@nigelkennedy7576]

Hi - have you considdered you may have blocked passage ways in the block? 12 psi at idle seems high - would have though it should be 5psi or slightly less on muffs. WOT is normally less than 25psi. Could be why you blew the poppet gasket too.. Regards from the land downunder - New Zealand.

[@gordonwrichert8240]

any chance of the cylinder head gaskets being on the wrong side or up side down with high preasure and no thermostat that motor should be ice coldyou are getting good flow out of the pee hole some thing must be plugged

[@ADDvanced]

No. I think something in the midsection is plugged. Pee hole works but I don’t think I’m getting very good flow down the exhaust

[@lafountainmountain3244]

Over heating on these is about 180 and above on these i believe. Maybe alarm going off cuz oil gear isnt spinning consistantly and motion sensor throwing alarm or did you solve that?

[@PowellRoadDIY]

My alarm was coming on but each cylinder wasn’t running hot at all. I could hold my hand on each cylinder head for mins and not burn my hand. So I’ve been sending it.

[@pgnandt]

Yes human pain threshold is about 160 F.

[@greenbaypackerfan4289]

Pike Lake?

[@airtightindustries]

The "snort"/lack of power on the holeshot, is something I've had on the first holeshot after running out of gas. I think it's an air lock in one of the carburetors

[@ADDvanced]

How do you bleed the system? I think I created a bubble when I tested the oil injection system

[@airtightindustries]

@@ADDvanced I'm most familiar with evinrudes, but I've had a number of times that on the first holeshot after carb work and entirely dry carbs, the boat has bogged for like 10-30 seconds only to clear up and rocket out of the hole! My line of thinking is there needed to be adequate internal vacuum to purge the main power jets. Not sure how you could force this.... maybe if you stall the engine with a rag blocking the carburetor venturies forcing the carb to suck fuel.....the only thing is the emulsion tube won't be drawing unless under load with wot. Maybe try to press the key for a primershot to act as an accelerator pump? Maybe someone can chime in with more experience than I?

[@pgnandt]

Just plugs fouling. Then clearing.

[@airtightindustries]

@@pgnandt how are the plugs going foul if they're brand new and the carbs are dry? I've never had a fiel/oil fouled sp clean itself up in my experience.

[@pgnandt]

@@airtightindustries I should say loading not fouling. Loading results in fouling. This exact scenario happened to me countless times running a J plug with too much idling. I went surface gap and problem went away. Running premix in a 225.

[@PowellRoadDIY]

Possibly the water deflectors in the power head maybe swollen… if mercury carries them. I know my Johnson does.

[@michaelmurrietta2263]

Mercury's don't use them

[@lesabre1972]

new sensor and impeller for the pump

[@robertpirtle3638]

The white line is water line . But that’s the spot I run my 86 merc on my three point Hydro. About a inch from the water

[@michaelheinsler5441]

Rob go to Bam marine and get a new sender and gauge the send is in stock and the gauge ships from the factory

[@switzer1750]

Great video, BOAT=Break Out Another Thousand, it the black box

[@ADDvanced]

Probably... going to pull the heads and exhaust anyway just to look at whats going on and learn more

[@K_M_M_G]

I’d say put a couple thermal couples on the engine and log the temperatures after a long ride. I have a strange feeling you don’t have an overheating issue

[@MnDan]

Where'd u guys go??

[@antonio.stefanelli]

if the carburetion is lean the engine overheats. disassemble the candles, they must be hazelnut color.

[@vinceburling4613]

A head gasket that is leaking combustion gasses into water jacket will also cause overheating

[@jakem5339]

Disconnect the blue wires from the oil tank float and see if the beeping stops. If it does the float needs to be replaced. This motor only has 2 alarms. Low oil and over heat.

[@ADDvanced]

I think I tried that but I will give it another shot.

[@kencraig6526]

The tale tale has plenty of flow, but with no tstat it may be flowing to fast. Could be blocked passage but I don't think so, my guess is the sensor or sensors are contaminated some how and reading wrong

[@kencraig6526]

I should watch the whole vid before commenting lol

[@reelkayaking9886]

My 1989 Merc 175 sees 18-20 psi at 5800 RPM. Around 10-12 at idle.

[@pgnandt]

83' 225 Black Max. 5 at idle 15-20 at WOT.

[@riverakers]

Less than 150 degrees on the cylinder head is not overheating.200 plus could be an issue.

[@stewartarmstrong7567]

Has it got deflectors under the heads like an OMC? Might be worth pulling the heads and checking for corrosion in the waterways as well. Good luck with her. ✌☺🤙 🚤

[@ADDvanced]

I'm not sure, can you post a link to a photo? Not clear on what you're referencing. Going to order a gasket kit for this engine and start taking things apart....

[@stewartarmstrong7567]

@@ADDvanced Hi I don't know how to post links and don't know if Mercs even have them, but makes sense they would. They are little rubber blocks that go in the water passages behind the heads to slow down the flow at higher speeds to make the cooling more efficient, and so the heads don't get cold water forced straight through the hot castings. Sometimes on a salt used engine they can get clogged up. If you can find a schematic of whats behind there before disassembly it should help you out. Cheers mate liking the content. BTW do you still have the yellow Jaguar?

[@bullykuldo6233]

Did you clean the water pick up tube that's in the leg ?

[@brianlavigne8853]

I've had switch boxes cause weird problems like what you're having. It might be worth replacing both of them.

[@ADDvanced]

There are two?

[@brianlavigne8853]

@@ADDvanced Yes, they are stacked one on top of each other. Each one services 3 cylinders.

[@scotscheideman9800]

The thermostats in that vintage of Merc/Mariner was 140°f

[@michaelmurrietta2263]

Oh by the way 12 psi at mid range is OK 20 at top rpms is perfect and by the way don't rely on temp gauge they never where accurate 42 yr tech

[@tobreak4505]

You might contact Stew at Dangar marine.

[@ADDvanced]

Love that guy!

[@mjodr]

I can tell you are a long term car guy that is learning all the in's and out's of how they designed these two stroke outboards. I went through all the same learning moments, lol. I thought I knew how every motor worked, then I bought a 1988 Evinrude 175 crossflow. Lot of "OMG, how dumb can I be?" moments. I got mine pretty much figured out by now, but I still have to learn how Mercury works. The starting procedure is interesting, as you finally figured out. They can be finicky no matter how much a motor/two stroke whisperer you are, but the priming system is an interesting challenge to master. Also, the cooling systems on outboards is so different from anything on land I had to spend some time learning. FWIW, my Evinrude 175 never even gets warm. You definitely have had a hell of a time overheating that motor way too fast, lol. I can tell you right away, though, removing the t-stat(s) in this episode was a bad idea, lol. It actually needs them. Again, kinda gotta throw the land vehicle knowledge out the window.