BF 115 no compession

[HD_Bob]

I have a 22' Boston whaler with 2 BF 115s on it. I was told that one of them one day just wouldn't start. When I started checking I found no compression on all cylinders. Further investigating I found it has a new timing belt. Will this engine bend valves if the belt brakes or is installed wrong?

Thanks, Bob

 

[Mas]

Re: BF 115 no compession

Check your compression tester on the good motor.

MAS

 

[Mas]

Re: BF 115 no compession

I do not know your particular motor, but if you have zero clearance valves, like Honda did on some of their cars, the pistons will bend only the valves that are open at the time (been there done that). The ones that are closed will not open to bend because the belt broke. Now if you have zero clearance valves and the belt was reinstalled incorrectly, then conceivably, all your valves could be bent.

MAS

 

[HD_Bob]

Re: BF 115 no compession

Thanks for the reply. I checked the tester on the good motor it had 210 PSI. Here is what I found. Mud dobbers had built a nest on the crank pulley for the timing belt. When the motor was turned over it ran all that mess through the gear and belt filling in half of the teeth. This caused the belt to jump about 30* every revolution of the crank. When I found this I pulled the head and all 16 valves are bent. I just wasn't sure if this was an interference motor, now I know.
Thanks, Bob

 

[Alumarine]

Re: BF 115 no compession

Wow, good luck with that.

Those are nasty little things aren't they.

 

[steelespike]

Re: BF 115 no compession

The scarey thing is it could happen again.

 

[Mas]

Re: BF 115 no compession

Replace the belt on a regular maintenance cycle. I'm not sure what that interval should be, but know that you'll be rebuilding the heads again if that $30 belt breaks.

PS Check for dobbers everyday???

MAS