1981 140 hp / how to check cylinder compression

[old141fe]

how do i need to check the cylinder for compression and what are acepatble readings for each cylinder, thanks Huck

 

[SparkieBoat]

Re: 1981 140 hp / how to check cylinder compression

pull all plugs..connect psi gauge ..test each cylinder with about 7 or 8 turn overs...anything over 90 is ok above 115 is good...all cylinders need to be within %10

 

[kenmyfam]

Re: 1981 140 hp / how to check cylinder compression

Check this link out.
http://forums.iboats.com/showthread.php?t=313963&highlight=compression

 

[emdsapmgr]

Re: 1981 140 hp / how to check cylinder compression

That engine has high compression heads from the factory. Likely the compression should be over 130 lbs on each cylinder on a new powerhead. The engine will probably run fine with somewhat lower compression, as long as they are even.

 

[old141fe]

Re: 1981 140 hp / how to check cylinder compression

thanks guys, if compression is good what suggestions for the next step of a tune up, i was thinking remove old fuel in tank, running a 50-1 mixture with amsoil, then new plugs, and cleaning air intake system, and checking lower end fluids any more ideas

 

[SparkieBoat]

Re: 1981 140 hp / how to check cylinder compression

new water pump impeller and gear oil in the foot