K&B 3.5 engine help...bogging out after put in water

[jimbo12mx]

i just bought this boat used with no knowledge it.....engine runs great while its not in the water, as soon as i give it a push in the water it dies out like theres water getting in the engine or the motor doesnt have enough power to push the prop through the water...any suggestions? does the motor need a rebuild?

[SteveM]

Inboard or outboard? What fuel are you using? Sounds like the motor is a bit too lean and I suggest opening up the needle maybe a half or even whole turn. When tuning a marine motor on the stand there is virtually no load and you may have tuned too lean.

[jimbo12mx]

its an outboard motor, and i have tried just about everything you can think of to get this thing to run...ive richened it to the point that theres excess fuel coming out the exhaust.

[jimbo12mx]

running 30% fuel

[SteveM]

Race boats often need a hefty launch otherwise the prop just cavitates and the boat goes nowhere. Are you just dropping it in the water or giving it a good toss?

[jimbo12mx]

nope im throwin it about as fast as i can...it almost seems like theres water getting in themotor somehow...but all seals are good and bolts are tight...i cant figure it out...could it just be that the motor needs a rebuild? out of water the motor sounds great and starts great..otherwise...no good

[SteveM]

It might need a rebuild but I can't be sure. Maybe you have a bad bearing.....I'm guessing at this point.

[HOTWATER]

The same thing happened to a guy I ran boats with. He tried everything possible (well...almost everything). We checked everything from fuel flow to glow plug, then while he tried starting it again, I noticed that the prop was spinning in the wrong direction!!! I switched the starter cable leads, fired it back up and He was running around the pond with no problems!!! Hope this helps!

[chiefss]

The K&B outboards do run in the reverse direction (CW) but it sounds like you have too much prop. My first boat had the same problem. Ran well out of the water but slowed way down in the water. The K&B engine will not run well backwards in or out of the water so that doesn't sound like your problem.