1989bayliner w/85hp force, starting problems

[catdaddy77]

i recently purchaced this boat and motor, im having problems starting the motor. i have fire at the spark plugs, fuel is ok, copression is 100# on top cylinder, 75# on middle cylinder, and 65# on bottom cylinder. i took the spark pluds out and the motor spins like a top. i put the plugs back in and it sounds like a car engine when the timing is off. i hope some one can help me.

 

[roscoe]

Re: 1989bayliner w/85hp force, starting problems

Well, the compression is for poop on two cylinders, and marginal on one. You should have 110+ on all three, and with no more than 10# variance between them.<br /><br />Pull the head and inspect. If you are very very lucky, it is only a blown head gasket. Good chance it was caused by an overheat, bad water pump.

 

[Schoe]

Re: 1989bayliner w/85hp force, starting problems

Roscoe is correct, but also check the battery. Force engins develope higher compression that regular engines. I had a weak battery and it did the same thing you discribe. I had to go with 1000 amps and that did the trick. You compression is bad. If the heaad gasket is good check for carbon on the rings which can sieze the rings in their slots and not allow them to expand to prevent blowby. Synthetic 2-stroke oil really cuts the carbon and smoke down to nothing.