My 25 hp kohler LT bogs at WOT, then it idles rough and i have to keep on the throttle to keep it running! i have cleaned the carb twice, i took all the paper out of the air filter that the previous owner had oiled, adjusted tha choke.

i pulled the plugs (which are only 2 weeks old) and one of them is grey white color and one is wet. im guessing this is my problem but im not sure what is wrong and how to fix it, im new to mud motors.

any help would be greatly appreciated!

about ready to give up and take it to shop! any of you guys know Bart Broomfield from franklin??

check the oil level. My 35 vanguard was bogging down when i got her up to speed and it came to find out that there was too much oil in the motor. And the oil wasnt over the holes on the dipstick. I hear in these motors you have to have the exact amount of oil. Not sure about the Kolers but something to think about

Check your compression... Then, make sure that both plugs are firing properly. The one that is wet may not be fireing properly.

I AM NOT A MECHANIC.

I only know what I am either told or read.


I hope this helps..


With Love,
Uncle J

Is one cyl. not firing? When it is running does it have any power? If one cyl is not firing for some reason that will cause your symtoms. The wet plug is what makes it seem like one is not firing. Make sure your running off both cyl.

I havent thought about the oil level but it could be possible because i changed it when i bought it two weeks ago and i believe i did over fill it a little . . bit . . too much!!

It does have plenty of power and i believe both cyl. are firing. at idle i can pull one plug wire and it will stay running, hook it back up and pull the other one and it stays running.

I was also thinking the timing might be off causing it not to fire at the right time, . . but i wouldnt know how to reset it if it was.

thanks for the replys guys!

The only way the timing could be off were if it had sheared the key for the flywheel. That is very possible. My 27 I had was running bad and no power. Sheared flywheel key was one of the problems.

When your cleaning the carb, did you take out any knock out plugs to get to all the jets in the carb? How bout your fuel line and pump. How long is the line and what kind of pump you running? How bout the fuel tank. Have you cleaned it to make sure its not a build up of water from the ethenol in the fuel? What color are the plugs?

I didnt take any of the plugs out because i didnt have a kit to put back in, i just took it apart and cleaned it the best i could with carb cleaner and compreesed air.

My line is ab 8 feet or so, i dont have a fuel pump, i just installed a fuel filter, i havnt cleaned the tank, tha last time i ran it i poured out all the gas i had in it and put 93 octane in it. one of the pulgs are greyish white and one of them are wet and black looking.

sounds like you need a compression tester to see if there is a mechanical problem.

yea wish i had one just to see, . .

i drained over half of the oil in it today, its now at tha full mark, im goin to tha river tommorow to see how it does i will let you guys know how it goes!

ya thats a lot of oil to put in the motor. If you drained out half your oil and after that it read full im sure that was your problem. I think on my 35 we had it at the full mark and it was giving us the problems. you still might need to take some out but who knows. its a different motor. Look in the specks and i think they tell you exactly how much to put in the motor. Or just call the manufacturer.

Yes i just got back from tha river, it ran MUCH better! idles much better.

but it still bogs at WOT, this is exactly what it does, . . i take off and run about 1/4 mile WOT running great, and suddenly it bogs down and dies, crank it back up (usually takes a second) i have to idle around for a minute and take off again and its tha same thing over and over.

i forgot to mention it only does this in tha water, i can run it on tha trailer at WOT all day!

does this motor have a rev limiter? im think i may be hitting it??

but when it takes a second to restart, i think its not getting enough gas!

You said you just installed a fuel filter? If so was it an in line fuel water separator? Did it run fine before that? If the filter is something new then it seems like you may need a fuel pump to help push fuel through the separator. Your motor does have a fuel pump on the valve cover more than likely. May have to add an electric pump to help it out.

tha fuel filter i installed was just a k&n inline filter, tha big round clear ones.

it ran tha same before i put it on, it didnt change anything, i just thought it would be good to add.

tha valve cover does have a fuel pump on it, if i have to install an electric fuel pump, where can i get one and what do they cost?

I run about 18 feet of fuel line with my stock kohler fuel pump. I am going to say that yours is getting weak or something. But I would try adding an electric fuel pump. You can get them from almost any parts store. Just want to get one that puts out 1-4 psi max. Should be less than fifty bucks. Just rig it up where it only comes on when the key is on.

did you clean that little solenoid on the carb. ? mine's was sticking doing the same thing.

no i didnt think to clean that, it does have a little bit of rust on it.

i put on my spare fuel pump tha was on tha motor when i bought it but tha fuel line connector was broke so today i drilled out tha broke piece and threaded in a brass hose connector, gave it a good cleaning, and i will run it tommorow and see wat that does, tha fuel pump is alot newer and cleaner than tha one i was running. , i dont know why i havnt tried this earlier.