Mercury outboard running rough - Final fix and engine runs - Troubleshooting Part 3

[@sewing1243]

From what I've read and seen (and I finally broke down and bought one) if you're having what appears to be fuel related problems with an outboard engine buy or borrow a small portable fuel tank, hoses, primer bulb, and the correct fitting for your outboard . Test the engine with that small portable tank (with new clean fuel and oil if you use premix) connected and if the problem goes away then you have a fuel tank/hoses/primer bulb problem. If the problem persists then it's an engine problem (fuel lines, internal fuel filter, fuel pump, Carb(s) ).

[@DennysCountryLife]

Well done Brett! I'm sure this will help out a lot of folks having the same issues. That's a heck of a nice pontoon boat by the way!

[@Sinister_YJ]

Great video, I am having the same issues. Back to the motor with renewed energy.

[@BamaFishn]

Good job! Exactly what my Triton Merc 90 is doing. Start on it tomorrow. Thanks for the series.

[@bucksgarage1]

Good luck. I hate getting stuck on the water. 2 years now with no more fuel issues.

[@timybib]

Did that solve your Mercury issues? I have been having similar issues with mine. I can't wait to give this a shot.

[@BasementShopGuy]

Brett - loved this little series. Was pulling for ya during all three episodes. I learned a ton and thank you for putting these together!

[@bucksgarage1]

Thanks man. I subbed you btw.

[@eallen3674]

Nice vid. When you put the new fuel line on the bulb should point upwards. There is a small ball in bulb. If front is pointed downward the ball will inhibit gas flow. I have same style pontoon and fuel tank.i was not aware of valve in fuel stem at tank.

[@DMD81773]

That valve is broken now that it rattles. Theres supposed to be some spring loaded tension on it.

[@greauxpete]

Had the same type of issues on my robalo 2320 offshore boat. Used process of elimination to find I had a combination of boat side fuel delivery issues. Ran on a separate tank to determine whether issue was on boat side or engine side. Proceeded to isolate each boat side component (filter, fuel hose, primer bulb, and yes.. pickup tubes) until I found the offending components. As it turns out, the fuel water separator housing was bad, the fuel line was bad, and my pickup tube was bad. Isolated pickup tube with brand new hose, with/without primer bulb and new hose, new hose without filter housing, etc.. you get it... It was hard to believe but they all combined to create an issue with fuel delivery. The boat is 20 years old and had hard piped welded in pickup tubes which probably cracked from running offshore in sloppy seas. I added a plastic pickup tube which bolts in the top of the tank with a fuel gauge sender type plate which can be easily accessed and changed if needed.

[@bucksgarage1]

greauxpete I believe it. It seems when it rains it pours.

[@mmiguy1122]

I wouldnt run the motor over a certain rpms on the hose. They taught us that in boat school. No need to have it revved up like that to start either.

[@bucksgarage1]

I have heard the same thing, nothing more than idle on ears. Now that its straightened out and running correct I keep it at idle.

[@daddski1]

those check valves were installed for a different reason. If a boat were to sink and/or roll over that check valve is there to keep fuel from running out. THe only remedy is an updated fitting or ppl do what you did. They were a nightmare for years until someone figured out a better way.

[@stephenjsumner]

I noticed the silver fuel line. Many of the old Mercury fuel lines fail because of today's ethanol gas. After removing the fittings, I noticed the lining had totally collapsed and caused the lack of fuel. I traced the black specs in the filter to the primer bulb disintegrating from the ethanol, also. I cut it apart and sure enough, the inside of the bulb was mush. Good luck.

[@mriguy3202]

Steve is right. The black crud is telling you something, and the water is telling you something. Find where the water is coming from, find where the black is coming from and address those issues. I think you were correct in suspecting that the water enters at the top fitting seal (which has a black gasket!). If you are not removing the tank and thoroughly cleaning it, then you will be replacing the fuel filter again. Modern gasoline is hard on old fuel lines.

[@bucksgarage1]

I'll be getting new fuel lines, primer bulb and cleaning the tank this year before she hits the water.

[@stevewaite123]

i'm glad I don't treat my cold merc 75 like that.

[@TheSlingwing]

Should have the throttle wide open for a good compression test.

[@jodytomlinson9281]

Great video man , totally learned something there.

[@brettlund2255]

I had a Mercury just like that and it always had something wrong with it I kept fresh gas in it kept up with maintenance and used it all the time with very little setup time but it never really ran right. So ………… I bought a Yamaha and never had that problem again.

[@ew7007]

I know this is a few years old but... Wow! Not sure where to start. I think you should really put a comment here that goes "Don't do what I did." I (and countless outboard mechanics) cringe badly when ever I see someone on YT revving the crap out of their outboard in the driveway on hose water. They are only EVER for idling. And I hope you replaced that impeller shortly after you ran the motor with NO water in the driveway. Lastly, WTF? No follow up? I found this looking for a carb rebuild vid and watched it to no avail. Oh well, marinas love things like this. Keeps them in business all year long. Best of luck with the boat.

[@johnappleseed936]

Cry more you bum

[@johnweber6420]

Water will boil up to the seperater when moveing

[@pppaulie73]

Replace your primer bulb and fuel lines from gas tank to the motor also.

[@bucksgarage1]

Yes sir. I did the next year. Been running good since.

[@craigd5169]

Throw that anti siphon valve in the trash and use a normal barb fitting, they will burn up an outboard when they fail and cause the motor to go lean, luckily you caught it at the marina

[@wally6629]

What is and Where is the Anti-Siphon valve your referring to? Pls let me know. THANKS

[@craigd5169]

@@wally6629 its a small inline check valve on the fuel pickup st the tank, looks like a bard fitting but ther risk a ball check inside of the fitting, they gum up and stick closed, they have leaned out and destroyed many many outboards

[@jorgecamblor6504]

Real good one.

[@handyallaround5776]

is this a 90hp? .....if so i have the same one ,, on a pontoon bought it with the linkage out of adjustment,, figured that out but now its having trouble cranking up , it was cranking perfectly earlier today,, have fuel,, have excellent spark, i messed with the idle adjustment screw and fear i messed up the timing , but , also at the same time fuel tank was low , but had a new filter on it ,, any ideas anyone?

[@bucksgarage1]

bent rodguy it's a 50 hp but should be about the same. Messing with the idle adjustment shouldn't have too much to do with it starting. Are you able to put it oi n neutral and adjust the idle up with the controls? Mine has a button in the middle of the shifter, when you push it in you can advance the shifter forward and raise the throttle without having it in gear. Why do you think it's out of time?

[@shannonrose2590]

compression test is done with throttle wide open and kill switch on

[@bucksgarage1]

Shannon Rose Vlog's it doesn't have a kill switch and I was really just checking to see that they were all similar.

[@edhughes6567]

Doesn't matter ,no valves so it'll be the same either way.

[@thom7623]

Change gas stations that's a lot of water in the gas also there is an additive called heet try that

[@LTDCrownVicFanakaRoyalTsnumber]

Sounds like a V6 revving up

[@jessicagriffin1357]

I have a 2003 Mercury 90 hp 4-stroke. It cuts out at high speeds. It recovers when you let off the throttle. I replaced the fuel water separator, replaced the fuel pump, had the carbs and all the lines replaced, plugged in an external fuel tank with fresh non-ethanol gas, ran her and she still cuts out at high speeds. Thought for sure this was a fuel problem! Any suggestions what to try next?

[@bucksgarage1]

Possibly bad grounds? Check them and make sure they are tight and corrosion free?

[@jessicagriffin1357]

Buck's Garage I had all the grounds checked. And changed all the spark plugs. Now it runs well at low rpms when you first start running her, but engine bogs down at higher rpms. After a while it runs rough at all rpms. Any suggestions?

[@bucksgarage1]

@@jessicagriffin1357 I just reread this post and saw your motor was a 4 stroke so nevermind on the reed valve thing. Did you check the compression?

[@jessicagriffin1357]

Buck's Garage we haven’t checked the compression yet. Planning to have that checked next!

[@bobbyrobinson7825]

check the voltage regulator. Mine was shorting out with bench test. Replaced it from a 35.00 one on Amazon and good as new!

[@BamaFishn]

Brett worked on my 90hp Merc all day, drained tank, pulled carbs checked jets all fairly clean. Put it all back together motor still muddy. Fine on hose terrible under load. Going to trouble shoot coils and spark and compression this week. Any ideas?

[@bucksgarage1]

I would check the compression for sure. I bought a jet ski last year knowing it had issues, it idled fine but didn't have much top end. It only had 60 psi on 1 cylinder. 120 on the other. May be a bad coil? Hope you get it straightened out.

[@bouldernelsonbigfoot]

So, your check vavle is most likly clogged with tiny pieces of the old plastic fuel cell.

[@kevinvey2658]

150 2006 efi runs cold excessive water flow from exhaust port changed stats cleaned poppet valve what could be wrong can you please help thanks

[@Mrturbo135]

Also no affense but if you run that motor that high on rpm out of the water, you will fry it

[@wally6629]

Ethanol FUEL builds up in those, and they become JUNK. Trash it, just run a free flowing barb fitting!

[@kevifell]

Hey, quick question for you. We have exactly the same outboard. When you turn the key to start it, does it take a few tries before it actually starts? Or does it go on only a few seconds? Having a bit of trouble with mine... Thanks Kevin

[@bucksgarage1]

If I choke it it fires up withing 10 seconds normally.

[@kevifell]

Brett Buckley thank you, where is the choke?

[@bucksgarage1]

You push the key in when starting and that actuates the choke. See video - kzbin.info/www/bejne/iKS1mJeAgcqcncU

[@kevifell]

Brett Buckley got it !! Thank you sir

[@adamkurschner]

Aren't you supposed to ground out the plug wires when turning over the motor with no plugs installed?

[@cezarycezary4180]

Hi there! I got the same issue! I have mercury EFI 4 stroke 50KM 2006 year. My engine starts to choking first then it runs off. I got tps sensor problem and check engine. What do you think about that? Greetings!

[@bucksgarage1]

From what I have read online the Tps is a high ware item and has issuer some times. Are you able to see what the check engine codes are? I'm guessing the Tps is at least $150 so that would be really expensive to replace with out being positive it is the issue.

[@cezarycezary4180]

​@@bucksgarage1 Hmm I can't check the engine code as far as I know. A boat computer shows those 2-3 errors. TPS fault, Check Engine and Limothrottle (something like that). The engine of course shows few "biiips". Do you think I should check the wire first or the connections between lever and engine? The connection of TPS into engine? Could something be dirty and should be cleaned before re-place TPS unit? Thanks for your reply

[@bucksgarage1]

@@cezarycezary4180 that's where I would start. Clean the connections with electrical contact cleaner.

[@smallenginerepair7921]

CLEAN your Carberators your engine sounds like it's not running on all the cylinders correctly

[@crazymc3909]

Clean your carburetor jets with compressed air or somthing litte that with go throw your jets hole. Your engine does not sound like it running on all cylinders for a 90hp

[@sbuzz5889]

get rid of the fuel kill weeds?

[@makistsigaridas1916]

Καλησπέρα φίλε. Έχω τή ίδια μηχανή mercury 2 strong 60 1997 μπορείτε να μου πείτε πως θά αλλάξω το impeller... Ευχαριστώ πολύ φίλε

[@12591259]

Yasou Makis, se voithese me thn erotisi sou?

[@michaelkoolaid]

Do these engines actually idle smooth? I mean mine idles but it seems choppy to me. My last boat was a javelin with a 115 Johnson fast strike which idled pretty smooth I though. My new boat is a 2007 txw 175 with this exact motor show here on it (2007 merc 50 hp) and it seems to idle less smoothly. I have pulled the spark plugs recently to see if I was running lean as I think I can hear a sneeze from it every now and then at idle but my plugs are a brownish tan color with a little oil residue a little way up the threads. I figured if I was lean my plugs would be white and have no brown at all. The engine runs fine in gear at any rpm, just doesnt like to idle smooth and dies when I try to let it idle cold.

[@bucksgarage1]

Mine is not the smoothest. But it's way better than it was before I started working on it.

[@michaelkoolaid]

@@bucksgarage1 mine dies if let idle for any period of time. If I run down the lake and come off of wot it idles fine but the moment I cut the engine off and start it back it doesnt want to idle. I'm hesitant to tear the carbs down as it runs great in gear.

[@bucksgarage1]

Carbs are easy. I had to turn the idle up a hair to get it to not have it quit from time to time. Now I can idle around the lake for hours without a problem

[@smallenginerepair7921]

The problem sounds like the carberators are clogged clean those jets they are easy to clog up if theres no fuel filter clean those carbs and you should be good to go, you obviously have spark and good compression so it's a fuel problem. I'm almost 99% sure

[@jeremycrosby5904]

my problem was oil container keep getting water in it

[@lionsdejudah]

Do you hear a 3 second clacking on deceleration from 2k rpm to idle?

[@bucksgarage1]

I can't say I do

[@lionsdejudah]

@@bucksgarage1 🤔easier to hear with the cowling off and it being rev’d down at the engine.

[@cajunfamily5227]

What size prop you running on her

[@raydijkstra8546]

You put the earmuffs on bacwards. thats why they slip off

[@bucksgarage1]

Ray Dijkstra your saying the metal that holds them together should be up near the prop?

[@crazylewiemike]

What size motor is that

[@bucksgarage1]

50 hp

[@luisehbauer4076]

Which lake or river is that?

[@bucksgarage1]

Luis Ehbauer lake tomahawk in ohio

[@luisehbauer4076]

Brett Buckley i can't belive it that you are allowed to drive on every lake with the motorboat // i come from Germany

[@bucksgarage1]

there are very few lakes over here that dont allow motors. alot do have a horsepower restriction of 20 though.

[@daniellockwood291]

you never want to adjust outboard carbs out of the water

[@bucksgarage1]

Daniel Lockwood you are correct. I had to adjust it a few times last year before I got it right where I wanted it.

[@bigdodgeram59]

The way you ran that on the muffs was cringe worthy. Lucky you didn’t mess the motor up... It also clearly says in the instructions DO NOT add a additional filter in the installation instructions which you obviously didn’t read. It tells you that it causes vapor lock, hard starting ect.... Hopefully someone reads this before installing one of their own on the boat and going by what you did...This video as a whole shows people exactly what not to do on installation and how to not run your boat on the muffs or period...