1988 Yamaha 115 V4-Compresion?

[thehermit]

Motor has between 100-95 basically. It seems used and weak now. what is the normal compression?<br /><br />TH

 

[rodbolt]

Re: 1988 Yamaha 115 V4-Compresion?

no set numbers. all must be within 10 psi. if ya really want to know the condition of the sealing capeabilities have a leak down test done. a world more accurate than a compression test.

 

[thehermit]

Re: 1988 Yamaha 115 V4-Compresion?

thanks rodbolt. All are within 10 and prop is turning @ 5600 @ WOT. Guess I could re-prop to compensate for loss of power and boost WOT to 5800 or 6000. TH

 

[rodbolt]

Re: 1988 Yamaha 115 V4-Compresion?

the 88 115 max rpm is 5500. if you suspect a problem have it run up on the test wheel or a dyno.