2002 Islandia compression test

[alucard2391]

Anyone know what each cylinder psi should be on the 240 merc

 

[poppie]

I believe its supposed to be around 125 psi.

 

[alucard2391]

Thanks for the reply I have misplaced my owners manual somewhere time to rip the house apart and find it. Thanks again

 

[Tim75]

Anyone know what each cylinder psi should be on the 240 merc

The last time I tested mine, it was 135 psi; tested with battery charger ON, all spark plugs out, and wide open throttle.

According to Dr. Honda, 120 is weak, but should run. IF they are equal.

 

[Dr Honda]

It's hard to say exactly. The Merc's had different pressures for different HP and different years. at 125 psi... it should run. FYI... my 240EFI is well over 145 PSI cold. BUT... I did shave the block when I built the engine. (I can get 6300 RPM, and will push my big a$$ Islandia to 50 mph with the top back, and just me in it)

Normally... on a fresh build... with an "O-ring" block... you should see at least 135 psi.

With a 2-stroke.... as the rings wear... and you get blow-by... it will displace oil, and eventually the pistons will fail. so... while there is a "Spec"... if you notice compression starting to drop... do a rebuild before a meltdown. It will be cheaper in the long run.