What You Need To Know About Mercury Optimax's! | Troubleshooting

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There are a couple of basic tests and procedures that a lot of people skip over when trying to troubleshoot a Mercury Optimax. Here is a short video that goes over the basics which should get you pointed in the right direction.
Starting with splitting the chaps to make life so much easier, then doing a spark and compression test. Optimax's are known for failing coils. So a spark test will show you if this is one of the problems.
*** IMPORTANT!!!!!*****
CERTAIN OLDER OPTIMAX'S HAVE COILS THAT CAN SHORT OUT EXPENSIVE ELECTRONIC PARTS! MAKE SURE YOU KNOW WHAT OPTIMAX YOU ARE WORKING ON BEFORE SWAPPING AROUND PARTS WITH ANOTHER ENGINE!
Checking the air and fuel pressure on an Optimax next is super important to properly diagnose the issue. If the air pressure is not where it should be the fuel pressure will not build either.
Sometimes people can chase fuel pressure without even fixing the air pressure and waste many hours fixing something that wasn't broken.
Most Opti's require 90 PSI fuel and 80 PSI air. If these pressures are off, then start with the air pressure and check the compressor by clamping off the air dump hose on the PORT fuel rail. The pressure should spike, then check the fuel as well.
These tests can get you up and running way faster than anything else. Usually, a spark plug, ignition coil, or some dirty fuel filters are what the problem is with an Optimax!
***Disclaimer*** This video is just a visual aid for locations and parts of a normal service.
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This video is just a visual aid for locations and parts of a normal service.
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Enjoy the Video! Thanks for watching and don't forget to like and subscribe!
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[@BornAgainBoating]

Suggest Topics That You Would Like For Us To Cover On Technician's Tuesday! www.bornagainboating.com/technicians-tuesday/

[@alibornot6082]

Born Again Boating I have a Mercury 115 saltwater that is leaking water from the top of the midsection any advice what could it be?

[@walterhampton5955]

My 2010 150 optimax keeps stopping at idle

[@peteabdu9179]

taking apart a VST in an optimax

[@jmatak9]

This video might be 5 years old but has to be the best video I've found on trouble shooting a Optimax with clear instructions and explanation. Thank you for posting!

[@BornAgainBoating]

Thank you!

[@darylreadman3596]

Wow you can tell you do this for a living. Just info packed videos condensed down to alot of the issues with an Optimax. Thanks!

[@anthonyscocca7205]

The best diagnostic overview for optimax on the net. Thank you

[@stevepritchard9544]

Great Blitz around the pieces quickly, much appreciated.

[@claireaddison3589]

Great information and all true...unlike most of the crap that's on you tube about outboards. Nice to listen to someone who knows what he's talking about. Keep up the good work.

[@BornAgainBoating]

Thank you!

[@larryleblanc1551]

@@BornAgainBoating Hello. I believe I made a request. I like your info. Good voice. Precise. I loved it. Maybe a bit swift but great info. Thank you.

[@hankjivecrankmaster207]

Responding to comment by Edward: BAB, I find that when videoing, it helps to "pan" to the detail, then purposely hesitate on the detail item you are showing. I think the pace of your videos is good, quick and succinct, I just replay segments if need. Also there's a speed feature (in settings) in the bottom right of vid toolbar where one can slow down or speed up the video, very handy. When looking for a reference vid, I usually hit the "under 9 minute" vid first, then look for longer ones if needed, seldom would I click on a 22 minute vid to start with. Cheers, and thank you for these vids!

[@andynavarro5543]

Best video ever! I hate optimax for a lot of reasons but your video is awesome and definitely helpful. Thanks for posting

[@BornAgainBoating]

Your welcome :) thank you! I hope it helps a lot of people at least get pointed in the right direction. Boating is more fun on the water than at the dock ;)

[@TheAxeman2112]

Thank you so much for doing this video. I am auto mechanic trying to help a friend out with his Optimax 200 and its helped me in a very short time to see and understand how the fuel system works. I am looking at what looks like two injectors and compressed air to the fuel rails. So as a auto mechanic I needed to find out the scoop. You covered exactly what I needed to make the correct diagnosis.

[@BornAgainBoating]

Glad it was helpful!

[@Sailor6666]

Thank you so much. Im a rather new Optimaxuser and this video is just superb for a rational troubleshooting... Im actually having the same low pressure result that Luis Monzon stated here below (70-80 on a 200 Hp, Year 2002, 350 hours ). But the engine doesn't show any other symptoms to be inaccurate - it runs pretty great in all rpm-ranges. But I'm following your conversation with great interest... Thank you once again.

[@BornAgainBoating]

Awesome! Thank you for commenting! :)

[@bflavasonthetrack]

Excellent. I’m in the process of buying a 22’ triton with this motor on it. We did the compression test today. Left to right top to bottom 80,75,80,77,80,75

[@bflavasonthetrack]

@bornagainboating but how are those compression test results?

[@Hamchuck112]

Thanks a lot for this video. My new to me 2007 225 Opti went on its first trial today at low RPM. Never had an issue starting, but has never really been under load except for a few short bursts today below I'd say 3500rpms. It shut off 5 seconds after starting up to make the 100yd trip back to the dock. When I turned the key off and then back on, the fuel pump was very noisy and higher pitch when priming. Did this constantly and couldn't get it to run longer than several seconds. Is it most likely the high pressure pump? I haven't checked pressures but I will after seeing this video. The engine is beautiful and looks nearly new with 700hrs on it, but I'm hoping it isn't going to turn into a headache. Thanks again!

[@Hubjeep]

2:18 Thank you for explaining the second injector... I'm considering going from my 1994 Merc 2.5 (carb) boat to a 2012(?) Optimax boat. I'm a DIY (I maintain everything I have)... this Opti looks a bit scary to me. I have heard about compressor failure destroying an engine, but I also heard coils are $400 a piece, just searched and found aftermarket ones for $60.

[@colbybud]

never ever put an aftermarket injector on an outboard. The pintle can come loose and take out the cylinder. they are essential for engine health that each injector fires the same amount of fuel. This is why you have them cleaned every 300 hours. Pull all 12 injectors and send them off for cleaning. You can buy used injectors for about $250 each there is a company that sells them.

[@paulbickley658]

Good video, I thought the description of the process of troubleshooting was said quite fast and hard to comprehend anything even though I have mechanical background. I suggest anyone else including myself would have to listen to this at least a dozen times. I have a black optimax on my Ranger Boat. I am just learning mine.

[@brettmurphy4658]

Try turning the playback speed down to .75.

[@MohdAbbas123]

Thank you, very useful informations, I have mercury Optimax 225 m. 2008, I got problem with the fuel pump fuse, the fuse get burned, what could be the issue to fix..

[@richblake6932]

Concerning my boat problem I was wondering if it also could be the oil reservoir. There’s plenty of oil coming out in the filter is good

[@Rapbando]

You should have mention the reed valve pack because I've found one engine that was running at idle but couldn't ramp up because of all the screwes holding the plate of the valves dropped down in the air manifold I could see them just looking through the butterfly valve

[@Lulxiit]

I'm considering between mercury 60 HP 4 stroke or a 75 hp optimax, would you say the 2 stroke needs more maintenance?

[@mehrmegerdichian3720]

Quick question, what should be the throttle plate position/gap at ideal and WOT I had a rough idle issue on my 225 optimax and after some troubleshooting I finally found a small pinhole on fule regulator diaphragm. After replacing it the engine is running much smoother. I've messed with the throttle plate during troubleshooting and probably missed positioned it. Problem I'm having is when engine is cold as soon as I put it in gear it stalls and take a few attempts, but when it's hot there is no issue. I replaced the reeds spark plugs and checked coils for proper firing.

[@kennyfok168]

Great video, may I ask a quick question, I have optimax 200 , when it start 30 second , It gone warning (STBD system fault 14), I check it have engine oil, what can I do coming time ?

[@melcowan2117]

My OptiMax 150 was running fine then suddenly went down to 1300 rpm and won’t exceed that despite moving the throttle forward. Got it checked and it wasn’t overheating.

[@mukunet]

Great video!!

[@BornAgainBoating]

Thanks for the visit

[@reelcs]

Aaron if 12v is applied to VST tank electric fuel pumps they should function correct? 200hp/2002 Mercury Optimax; both pumps high psi and low psi are not functioning. Have you seen that before? Engine been sitting in varnished fuel for a couple years. There is no psi at Schrader valve on fuel rail. Thx!

[@mikebryant9462]

I have a 2009 225 optimax and never has given me a problem and I haven’t cranked it in 5 months and tried to start it and it wouldn’t fire. I went and took the cowling off and fuel line was loose and leaking. Fixed that and still just spins. Help appreciated , like your channel!

[@22steny]

Wow this was awesome! I have a 135 Optimax and just had it in water this weekend for first time of the year. It started showing overheating but was pushing water out that wasn't hot. Any suggestions would help Great video. Also is there any yearly maintenance you recommend on this engine? Fuel filter water filter when should one change them?

[@BornAgainBoating]

Thank you! Make sure the temp sensors are working properly :) sounds like one has failed and is telling the engine it's getting hot. But also make sure it's not the compressor, it's best to put it on a computer and see the exact code and what's going on. Yeah, just your normal service, fuel filters, impellers, thermostats, the normal stuff. Do the fuel filters once a year if you don't use the boat that often, here's some more info on service: kzbin.info/www/bejne/lZ2YnqqYfd97eLs&t

[@stevagaga]

Thank you for the video, and maybe you can help me with my Optimax. I have one Optimax 115 from 2005, with 3 cylinders. The problem I have is not the motor itself, but the leakage from the top of the oil tank on the motor, when I tilt the motor (when I want to keep the prop out from the water, or when I am transporting the boat). I have changed the gasket, but it is still leaking when the motor is tilted. The oil tank is full, and I do not know what to do. Any suggestion? Thanks again:)

[@rickramberg]

I have a Mercury 115 efi 4 stroke. I'm looking for a good video on checking coils. We have a high end mis. We have changed spark plugs twice. Both times the issue seemed to go away. Only to return a short time later. We suspect its one of the coils. We've bought new coils, but would like a good way to diagnose the problem. Specifically at the coil itself.

[@maritimeus]

I have a 2004 Mercury Optimax 115hp on my 1996 Mako 19’ (just bought the motor with the boat). There is no fuel priming bulb (I checked). Before I do fuel pump or VST maintenance on my optimax, how should I ensure the motor is primed when I reassemble? Because there’s no bulb, should I assume that the optimax fuel pump will self-prime? It must not have been a problem for the previous owners and marine mechanics. Any suggestions or ideas for the procedure? Thanks

[@peteabdu9179]

Great video! Is there a cheape dail gauge kit or do you have to go with the one mercuary sells? Would like to do some diagnosis myself but don't want to shell out $400+ for some gauges that I might only use once..

[@joshchristensen3793]

Hey mate I have a 90 optimax it has a slight miss at high rpm but only some of the time any thoughts on what to check 1st

[@abauer9865]

Any recommendations for a spark plug tester like what you have in the video?

[@mrmrwilem4789]

Great video

[@BornAgainBoating]

Glad you enjoyed it

[@chuckatkins9534]

It appears that our 115 HP is over oiling? Starts briefly and than quits, may or may not start briefly again ? Pull the plugs and they are covered in oil? What should we be looking for to fix this issue.

[@makingcookingfixing]

Hi, thanks for your video. I have a 2003 Optimax 150. Always worked perfect until yesterday, I noticed that someone went on my boat and played with my throttle lever as it was still in forward position. This same day, after 4 short trips, after starting up, I put the throttle lever in forward and it did go in forward but it does not rev passed idle, same for reverse and on the smartcraft gauge it reads SENSOR POWER. Battery power is good 13.4V and when starting the battery voltage is 14.4V. I don't have diagnostic equipment, only a multimeter, do you have any tips for me? Thank you

[@earleclemans4836]

What do you know about the optional pitot sensor thats not hooked up ?

[@jamiecounter4290]

i have a 2001 225 optimax i started the engine after it sat for a few months and it was idling when i trying to rev the engine a little it started to miss fire i shut it down and now it wont start things I've checked are spark, i installed new plugs, air pressure at 80 when cranking fuel pressure reading about 82 when cranking, tracker valve is good and im getting power to the injectors but no fuel in the cylinders i pulled i plug and it was dry as a bone getting frustrated ! engine only has about 180 hrs on it wpould be great if you could cover the no start condition thanks ,

[@luismonzon4601]

Great vídeo thanks 👏👏

[@BornAgainBoating]

Your welcome! Thank you for commenting!

[@carlosblanco6272]

Have twin 2007 115 optimax's had the air and fuel injectors sent out to clean motors run well but both have like a spit back when idiling what is that? Also this weekend while backing up the trailer onto the water at the boat ramp i started the motors when they were tilted all the way up. One motor starred smoking heavly blue spoke like a lot of oil was being burned. It continue smoking oil through the whole day only when i raised the idle over 2500 rpm's but not as heavy as in the beggining. Now when i flush it at the hose seems to be ok what can that be.

[@roddyfamx4]

Have a 225 XL Optimax. We have fuel coming out of the tiny hole in the bottom of the air regulator? Any idea what could be causing that?

[@davidgibson5157]

2006 mercury optimax 150 revs high is it the tracker valve or air tracker or body said the tsp has a rubber o ring that makes the linkage to sum times to stick ? I took my throttle apart thought cable broke

[@ericelmer5289]

I have a 2004 Optimax took the boat in and they said through the Schrader valve there was no fuel pressure coming from that valve on the vapor separator tank. Do you think it might be the first pump the low pump or the high pump or a different problem? Thank you

[@richardshal]

Awsom overvue of the optimax fuel system

[@BornAgainBoating]

Thank you!

[@nobody46820]

Good grief! Looks like Mercury did a great job of over-complicating an engine! Just out of curiosity, can a shade tree mechanic do anything to service/repair/clean the air compressor or fuel injectors? Great video!

[@BornAgainBoating]

Ahhhh they aren't that bad :) Sure, just run some quickleen occasionally when you fill up the fuel tank! That should keep the injectors pretty clean! Also, stay away from ethanol fuel and stick to the REC-90, that helps too!

[@nobody46820]

@@BornAgainBoating Roger,Roger. What about when traveling internationally?

[@conleydyson8049]

When under power on the water the motor will not trim up all the way to get the boat on top end plane could this be a power trim solenoid switch ???

[@ryandavis9974]

I have a 2002 150 opti and it runs good but has a rattle in behind the air intake. Any suggestions on where to start

[@dombix2286]

Hello, I have a 2008 150 optimax, i bought it with compersor that blew apart, i bought the new compresor but i suppose the old one didnt blow apart for no reason, to be exact im suspecting my oil pump on the engine is not working properly, i tried it outside and it is working, it is pumping out oul every time i connect it and dissconect it to the battery, also when i turn on the priming process with the accelerator, it starts pumping nicely, but when the engine is running when i dissconect the output hoses there is no oil coming out, my outboard oil reservior is holding the pressure, it has a few litters of oil in it and the hoses seem good, i heard the on-engine oil tank caps can go bad but im not sure that is the reason that oil pump is not working right as it pumps oil when engine is not running(during the priming process). So my question is how much oil the pump should provide when engine is running and is it maybe possible my engine computer is for whatever reason not sending the right signals to the oil pump while engine is working ? It would be really helpfull if you know something on that topic, thanks in advance.

[@stephenmcdougald3052]

2005 175hp optimax, I can run WOT all day at 5k to 5100rpms but if I try to run half throttle the engine bogs down to an idle unless I either hold it back to wot or let it come to a stop and then hold it to WOT until it starts to Rev up again after sitting sometimes a minute or more. The smart craft usually throws a bell and engine blinking alarm and temp hits 150° while it's idling in gear and when it revs up and I can go WOT again it drops back to 120°. Any ideas?

[@morgancure1604]

what about if youre not getting spark?when i turn key on it chimes to let you know its on.. seems like most outboards do..mine doesn't nor do i hear the fuel pump come on..i have an 06 mercury optimax 90..i pulled the plugs and there's no spark...this motor has less than 100 hours on it although it has sat for 6 years...any sugestions would help

[@liorecitbon9464]

we fixed every thing like it should then it worked great and suddenly it stop in the middle of running the we turn on and died turn on and died some told might be a Low batary power ..? is it so important with optimax that battery will be super strong and new?

[@aymanabdin5501]

, , I did a pressure test today on Optimax 90, the air pressure was 75, all cylinders were the same , what that be a measure issue? thx Aaron!!

[@kylevantassel7259]

I've got one of these that runs pretty good down low but falls on its face when you give it the beans. Compression is dead on correct. Anything come to mind ?

[@rikwilliams4132]

Hi I have a 2009 mercury optimax 150 2 stroke Have a shifting issue is hard to shift in forward in gear reverse is fine Any tips would help thank

[@djrigga]

135 optimax problem starts runs okay it can be used flat out when warmed but when brought back to idle it cuts out when at operating temperature any ideas ??

[@andresaquinones5583]

I have in 2010 optimax 250 pro xs the fuel rail gets too hot and I cleaned the whole rail and it is still the same?

[@timswearengin9693]

My mercury pro xs 250 won't turn but 4800 changed coils and now 5000 rpm sometimes 5100 rpm.

[@RamonHadley-yw6iu]

Was wondering I have a 225 optimax 2007 just rebuilt it. Was going to the break-in motor is making a knocking sound and goes to half hour. Could this be the air compressor

[@landongarrison5442]

This is an awesome video! I have a 2005 Optimax 150 that runs great on WOT and most of the time at idle. It has recently developed an intermittent stumble or miss when idling for a while. The number 5 spark plug is completely black, while the rest look perfect. I replaced all of the plugs and wires and gave it a test run. Checked plugs and number 5 is starting to build up with carbon again. I checked the coil with the volt meter and it checks within spec. I compression tested the engine when I first purchased it about 150 hours ago and it checked out perfect and even. I checked the reeds with an inspection camera and from what I can see, they look fine. Would this lead you to a fuel injector / air injector gummed up? I've been told to change the tracker valve, but if it were bad, wouldn't it affect more than just one cylinder? Your help is very much appreciated! Thank you!

[@bryceban]

I have these same symptoms. Did you ever figure out your issue Landon?

[@cloudk2030]

Hey thanks can i hook up a standard tire pressure guage to the air and fuel pressure spots you pointed out

[@larryleblanc1551]

You need a fuel rated guage.

[@lanescott6628]

Just found this video. Do the spark plugs need to have the opening of the gap towards the injectors? Thanks

[@BornAgainBoating]

Not on this engine, they will work either way

[@all_you_can_anime2842]

I have a 2003 Optimax 150HP and it won't stay on idle. I changed all of the spark plugs and fuel filter but it didn't help. Do my motor have an IAC valve and where can I find it if it does have one? The engine start up ok but then the rpm would go down and turn off the motor.

[@scottjeske7890]

I need to replace the MAP sensor on my Optimax 150hp 2015 model. Any video on this? BTW, engine runs great until about 4400 RPM's. Any more throttle and the engines bogs down. Hoping this resolves the issue. Geat video BTW.

[@lorrieandrews5188]

Excellent and informative video - cramming a lot of information in a short period of time; thank you. I have a question: I have twin 225's on my boat; starboard idles a bit rough, will not go beyond about 4,600 rpm at wot and burns significantly more fuel than the port engine. Any ideas of the cause?

[@BornAgainBoating]

Youll just have to start with the tests in tge video. Maybe plugs, a bad coil, an open injector, could be anything :/

[@bakervinci163]

How do you compression test with key off ?

[@bakervinci163]

Oh, pressure valves

[@texashillbily]

Great Info. any suggestion on where to start to repair a very sluggish take off / plane 2014 Merc 300 opti DFI ? it runs great once it gets going Thanks

[@BornAgainBoating]

Possibly a propping issue. There's just a ton of variables that could effect that, not having any running issues once your going.

[@johnpike5836]

gotta be the prop. i'll predict its not the stock issue on there now. its very likely a racing prop stainless steel on there now. ask the people u bought it from if they have the original prop. or speak to a merc dealer, the specs should be stamped on that prop.

[@abill7228]

Why does my 2005 225hp Optimax Saltwater motor make a constant beeping tone when I hit 4400RPM? The engine is still pissing, I changed out the secondary & primary water/fuel separator filters, the gas is clear, and both oil reservoirs are filled.

[@alwayssharp]

Thank you

[@BornAgainBoating]

Welcome!

[@dtaylor6000]

Great video. What would you suggest checking if the option doesn't idle while cold? Once mine warms up its great. But until it warms up to about 125 it won't idle. Thank you

[@dtaylor6000]

Plugs are brand new.

[@BornAgainBoating]

I would start by checking the pressures and seeing where they sit. Could be a sticky injector :(

[@rogeratkinson592]

Should my Optimax 150 pee immediately, or does it wait until the engine is warm? I have fished a several years, but have never taken a boat out myself. My dad died about a year and a half ago and I now possess his Nitro 7. It has not been on the water in almost two years, and the batteries need to be replace. The cranking battery has totally died and I have tried charging it and reconditioning it. I also decided to replace the trolling motor batteries with Li Time (lithium) batteries, and am going to install a lithium charger, too. But, I already knew that the tell tale wasn't peeing from cranking it up a few months ago. I had tried muffs, but it never peed. I bought a large (soft) rainwater collection "can" and filled it up. That way the propeller can turn with no need for the muffs. Using both methods. it still never peed. I only found out today that I could screw in my hose to the left of the tell-tale. That did cause water to stream from the tell tale. But my main question still remains: Should the tell tale pass water immediately, or should it rely on the engine warming up enough to open up the thermostat?

[@abauer9865]

thanks for the video and all of the great content, i am learning alot. @2:25 you show and mention pinching off the fuel line and then you say to "watch for the air pressure to spike" but in the video is shows the fuel pressure spike.....was this just a miss speak?

[@BornAgainBoating]

They will both spike, when air goes up the fuel will go up as well, but this engine had an issue so I think I just used the fuel shot to show a spike

[@glendekoker3682]

I'm working on a 115 optimax cleaned injectors air screens where dirty. Started ran but soon after same problem? I had gauge on fuel cranking only 60psi fuel?

[@nicholasbeldock9904]

I have a 2012 200 optimax pro XS, I have changed plugs, fuel filter and it will idle fine and run great for the first 5 or 10 mins then will bog down and won’t go above 4,000 rpms without bogging, I don’t know what it could be ?

[@philipjung2361]

I have a 2004 merc 250 efi, the idle is running rough and creating a ton of smoke even when engine is up to temp. The gas has been replaced and so have the spark plugs. Any suggestions?

[@davidhood6818]

My optimax 115 hp dies after running at slow speed at idle after a while. I can squeeze the priming bulb which is flat and it will start all of the clamps are tight as far as I can tell. ???

[@jamesmcdaniel1012]

My 2008 optimax 150 suddenly started jumping from an idle to approximately 3000 rpm and then back to a rough idle. If I let it keep running it will do this over and over. Otherwise it runs excellent. Any ideas why this started happening?

[@SpannFun114]

Thanks for posting the video. I have worked through the tests but have a question. I have a 2008 Optimax 225 DFI. Good spark, good compression, good fuel and new filter, good fuel and air pressure. Sounds good out of the water. In the water I throttle up and can’t get passed 1100 rpm with full throttle. Any suggestion on what I could check next? Thanks

[@phoenixw2w]

Did you ever figure out issue?

[@SpannFun114]

@@phoenixw2w yep, it was a bad primer bulb. So simple.

[@phoenixw2w]

@@SpannFun114 Right on, thanks for the fast response.

[@thesupertruckerdave]

Where do I find the spark tester and remote starter switch? Great video

[@BornAgainBoating]

www.bornagainboating.com/product-category/mechanical-tools/

[@jca2908]

Great video 👍 Any suggestions to a 115 opti. that runs fine until ~3500 rpm when opening the throttle, then start to shake violently and then drops rpm rapidly

[@BornAgainBoating]

Thank you! Have you gone through any of the tests in the video? Start there and see what you find. It could be either fuel or air but you won't know until you check it out. Then if that is all correct. You might have a failed block water pressure sensor. If you have a smartcraft gauge see what it says for water pressure. If it is zero, that will put the engine in guardian as well!

[@jca2908]

​@@BornAgainBoating I have now started a cleanout of my VST which had a fair amount of gunk in it. if that doesn't help the next step is a proper bench test. If you could have a quick look at my video that would be great, maybe you recognize the issue. Thank a million. kzbin.info/www/bejne/q2Kxp3mYbc6dmbc

[@sophieprimiano2556]

my optimal 135 mercury 2011is beeping when the starter key is turned, not turning over. it beeps apx. 5-6 times. additionally, my trim motor isn't working, just a humming when switch is engaged. any help would be great.

[@christiangirard6634]

I’m having trouble finding the esn on a 1990s blue water series optimax it’s not on the bracket anymore is there another way to locate it

[@brentspaulding9220]

I checked my fuel and air pressure and the air is 80 and fuel 90. But when I buy pliers on the hose line it doesn’t spike at all. My engine is idling really rough but my compressor sounds fine no weird noises from it and sounds normal. When I try to plane off I feel like my engine has no power and I’m only going 30mph planned off when I use to go 45mph. My compressions are dead even at 120. I’m really stuck at why the fuel air pressure are perfect but it doesn’t spike when I crimp the lines? Could you please explain this to me?

[@davidhood6818]

After sitting in my garage this fall when I could not run it I have a file problem. It will start for a second and then die. Where do I start

[@dappelgren3062]

2006 115 Optimax. Goes into guardian mode and throws 8 different random codes in no particular order. I can clear the codes with vessle view app but boat will beep and not go over 10mph. 2091-23 guardian due to overspeed. 541-24 water temp. 701-24 oil tank A level. 711-24 oil level. 451-25 pitot pressure. 555-24 Air comp temp. 2092-23 neutral overspeed. 1012-25 trim pos.---Water pump replaced and flowing great. Only has one oil tank on top of engine always full and currently oil sensor is bypassed. Swapped out water temp guage. New spark plugs. Oil pump pressure confirmed. Starts and idles great but will not rev up much higher than 3000 rpm without faulting out.

[@stevagaga]

Hi, I have almost the same issue. Did you fix your motor and how?

[@leonleong3744]

Hi morning I'm Leon, may I know how much of de combustion spec on optimax 250?

[@michaelmurrietta2263]

good video

[@michaelbaker1506]

I have a 2005 with a alarm going off at 4100 rpm and at 4200 hits Rev limiter

[@adventureairinc7355]

hope you still read here: I can get a cheap Optimax 200hp (built 2003) which has a high idle speed (1550 rpm). Any ideas for the reason? I don´t want to have to buy a new compressor etc.

[@duro845]

Excellent info 👍 s up

[@BornAgainBoating]

Thank you!

[@brian3.2]

Thank you for this great video. I have a 2007 90hp that will bog down and surge at 3k rpms. No alarms are sounding. I changed th fuel filter and cleaned the vst. Any advice is greatly appreciated.

[@BornAgainBoating]

I'd say to start by checking spark and looking at the plugs. Then check the pressures :)

[@brian3.2]

@@BornAgainBoating I just had a tech come out and they said the alarm is oil level high. They replaced the tank and the code is still there with no beeps. The boat goes into guardian mode. He now says I need a new ecm. Is this a common failure point? Thank you for your time.

[@BornAgainBoating]

@@brian3.2 Ouch, ummmm, well, it does happen. If it goes into guardian that quick, have the tech look at the block water pressure. If the engine doesn't see water pressure than it will automatically put the engine in guardian mode. Unless the ECM really is bad, but it's hard to say without seeing it!

[@charlesbalfour6544]

I need help I have twin 1999 mercury dfi the motor starts and dies right away replaced the fuel pumps motors sat for a few years am beat over it I really need help

[@rc4you891]

great video i sub keep up the good feed

[@BornAgainBoating]

Thank you!

[@tonchido]

I had 200 hp,my god does it burn petrol,loved the sound in neutral.

[@MajesticProduce]

What causes an Opti to quickly foul all the spark plugs?

[@captchris7362]

Dealing with a 225 pro xs with high fuel pressure at 120 130 psi have no run into this before thinking regulator or trash in the fuel rail any other thing you seen

[@kristievanthul7086]

Where do I get that manifold for air over fuel,and can it be modified to also test low pressure over air

[@BornAgainBoating]

I'm sorry, I don't think I understand the question :(

[@bhyroolpersaud2707]

My 225 year 2000 murcury optimax is idling high I try troubling everything can't find the fault. Help

[@alvarocastillo162]

When I measure the air, fuel and air come out, I would like to know if it is normal, thank you

[@TheDoug9901]

I run 2 filter traps for fuel and one on the engine very seldom have fuel issues. Still get shitty fuel sometimes the primary filters save me and got me back home.

[@TheDoug9901]

Once it was nip and tuck I was draining water from the one trap to make it back the last 3 miles. Without 3 traps I would have never made it back.

[@aaronboesel1506]

I have a 225 optimax. It runs fine for abit and long eniugh for a ski. But will then beep and possibly cut out... the motor has also had issues with going through spark plugs to quickly.

[@BornAgainBoating]

Have to check your pressures and make sure the engine is not overheating or oil. Really need to hook it up to a computer and find out what the beeps and codes are!

[@brentspaulding9220]

What I don’t get is how can my fuel:air pressure be perfect but when I put my pliers on hose line it doesn’t spike? How are the rails getting perfect psi but the hoses aren’t? I’m so confused

[@scottbellamy1844]

l have done most of the things in the video ,spark plugs ,checked coils cleaned vst check air &fuel ,changed out TPI but my rig runs great above 3500rpm but surges at about 1500.l have new fuel injectors and had air injectors cleaned after putting on a computer. still runs rough but not dying as bad after it warms up. Any ideals the guy who looked at it on the computer said I have a stretched hot foot cable keeping it from proper tpi adjustment. My opti max 225 Pro XS is a 2006 all but 1 cyl.compression110 number 6cyl 100.

[@BornAgainBoating]

Hello @scott bellamy I can't think of anything specific that could be causing that type of an issue. Something should have been a miss while doing all of those tests. It's possible that one of the ignition coils is beginning to fail and then at higher RPM's it is getting more juice so it runs fine. It's hard to say for an issue like that, without being able to look at it :( Sorry I don't have any tricks or oh yea it's this, kind of information for you.

[@RamonHadley-yw6iu]

The video is great