Yamaha 115hp Running Rough pt. 1

[July 2018] 2007 Yamaha 115hp. This engine has been running very rough. Unfortunately it hasn't seen much use in the last 4 or so years, only the garage. Wont produce more than 4,000 rpm and barely runs. I attempted a Seafoam fix, hoping that would unclog the gummed up engine.....results were not good.
to be continued.........

[@mxr7586]

Ppl got to quit wasting their money on sea foam. Clean your fuel filter, carbs and so on. Check spark and compression on each cylinder then check your spark plugs see if they’re wet or dry. If you don’t have enough fuel getting to one or more of the cylinders and you run it too long lean you will mess up your motor.

[@MoparYEEEAH]

sounds like you need to get your injectors cleaned, clean the VST and look at your plugs to start. new fuel filters all around can't hurt either.

[@DougW224]

Yep, you hit the nail on the head....... After I diagnosed the bad injector, I cleaned the other 3 and replaced the 4th. They were partially clogged if not more... After cleaning and replacing the 4th, the engine ran great..... In the end I just replaced all 4 injectors with brand new ones because they were inexpensive......As for the VST filter, I replaced that a year before these videos. It was the first thing I attempted to get this engine running right. Unfortunately it still ran poorly, and back the garage the boat went for another year.......After the injectors, I changed out all filters, new plugs, and now she runs perfect..... I unfortunately neglected the engine for too long and the result is what you see. My mistake....I now use Ethonal Free Fuel and use Gas/Fogging oil mix when I put the boat in storage for long periods....

[@AlexJones37]

Just took my boat in for this same issue. I figured it was fuel filter or bad gas.. turns out it was the fuel injectors

[@csinalabama]

my 2017 90hp was missing and I took it to the dealer suspecting power pack failure because that is what happened with my Mercury 60. They ask me if I put-putted on the lake at 3000 rpm all the time or if I ran it WOT on occasion. I confessed to put-putting and they told me to change the plugs every 2 years or run WOT more often. It worked.

[@dklassy6865]

Thanks for this video!

[@DanielGlatfelter]

Mine was doing the same thing, ot was a little rubber groumet had cracked on top of the high pressure pump inside the vst.

[@pattoallen1981]

Sounds like its only running on 2 cylinders to me

[@punishr36]

Yep.

[@mazdagine]

Sounds like it’s not firing on all cylinders

[@MEGA_SOKO]

I can't believe you took a risk of running the motor on gas that's almost 5 years old! If you fixed it yourself, you lucked out. That would be a pretty expensive fix at a shop.

[@captofthe7279]

Just needs a little tune up! Of course it’s gonna run like crap. Been sitting

[@DougW224]

Yep.... sitting and being neglected..... not gonna happen again!

[@eddieabraham3341]

Too much talk not enough action!! I've fixed dozens of this kind of problem. Some were only dirty injectors; Some were only bad spark plug leads; The worst one was a stuck oil ring on #3 piston causing the spark plug to foul resulting in a rough idle, misfiring condition. Yours looks like an easy fix...sounds like dirty injectors...good luck!!

[@DougW224]

ended up being partially clogged injectors and one bad one that wasn't working at all... my main problem was the one bad injector. Once replace, and after cleaning out the other 3, she ran perfect..... always a good feeling figuring out the problem in the driveway and not having to take to a mechanic.....

[@2fast4you25]

Tried changing plugs and cleaning injectors ????

[@markotto3334]

I don’t think it sounds like all cylinders are firing

[@jdxpointe1]

Check the IAC / AIC too

[@czwhat328]

Fuel filters and plugs

[@armandorosales5564]

Check your vst filter

[@kflo1219]

Water stream looks weak...I changed my water pump and much stronger stream now.

[@BroadBillHunter]

broo having the same problems w my 2007 115.... tell me WHAT fixed the rough running? im thinking its a fuel pump

[@DougW224]

My problem ended up being one of the 4 injectors was not working..... fuel system is a likely cause if your motor has been sitting alot...... start at the fuel tank and check everything from the fuel pick up, fuel liines, change filters, and check the plugs..... if no good results then clean or replace the injectors. They are cheap.... 4 pack was $40 on amazon.... solved my problem

[@BroadBillHunter]

​@@DougW224 thanks sounds like the answer to my problem aswell. well see

[@Busterchimes.welding]

Worst thing for an outboard motor is to not use them

[@DougW224]

Totally agree....

[@deronlowatta7575]

Clean the carby

[@AEeminc]

Old fuel