motor compression

[sylvain N]

hi every one i have problem with my evinrude 1985 150 hp start to change my electronic first i have a crack on one power pack order new one from evinrude they send me a replace number for my new pack install it run great at idle but don't have any power in gear every time motor stop but whith the old one no problem put brand new carburator kit still doing same thing check my compression is 75 on all cylinder i know minimum is 90 but 75 it is badfor this year run great before any HELP please

 

[jbjennings]

Re: motor compression

I'm thinking your motor has great compression for that year model. I doubt it had 90psi on the showroom floor. I'm suspecting from your description that you have bad spark on several cylinders and that is why it's falling on it's face when you give it throttle.
JMO,
JBJ

 

[JB]

Re: motor compression

There is no real minimum, sylvain. Differences in testing conditions, guages and technique can make as much as 50psi difference.

If your cylinders read within 10% of each other, and I see that they do, your engine is healthy.

The big JohnnyRude V6s usually test from 60 to 100psi when in good condition.

If all conditions were ideal, you had a very good guage and you used perfect technique (see The Top Secret File ^^) you would probably measure over 90psi, maybe even 100psi.

 

[sylvain N]

Re: motor compression

i test my fire with test light all good i don't know if is the coil went bad at some point
when i am in full trotle higth speed look like fire cut

but my biggest problem is why new powerpack don't work and the old one work
new one was ordering from evirude

 

[sylvain N]

Re: motor compression

were is the secret file

 

[wilde1j]

Re: motor compression

See here:
http://forums.iboats.com/showthread.php?t=299680

 

[Fl_Richard]

Re: motor compression

OT but I gotta say - Whoever named the most important section the secret file was crazy. (hope this wasn't you JB - just looked sorry tdaddy) Everyone has a hard time with both finding it and understanding that it contains all the secret information they need.

Cant someone make this easier for the newbies to find? At least give it a meaningful name.

 

[wilde1j]

Re: motor compression

The name probably doesn't make a difference. People fail to read the big message about replying to old posts too.

 

[Fl_Richard]

Re: motor compression

Too true

 

[JB]

Re: motor compression

Well, we wanted to call it "ADULTS ONLY!!" but that title is already used elsewhere.