FORUM RULES UPDATED - The forum rules have been updated to continue to provide a friendly and safe environment for our member community. Please take a moment to review the updated rules and our terms of use and privacy policy. Click here for Forum Rules which has links to the 'terms of use' and 'privacy policy'.
In Other News . . .
You will notice a few enchancements to the forums to make your experience better. These include: Email Notifications, Thread Previews, Thread Starter Notation, and Emoji Options on the 'Like' icon. . .
Additionally, the merchant portions of the website have been updated and are now operational. . . . Check out iBoats for all your boating gear.
Just got an 1988 Johnson 70 HP have not tested in the water yet runs on the hose OK compression is equal in all three but at 75lbs. I assume this is low. I could see if only one piston was producing a low number but all three what could cause this?
confirm the compression gauge you are using, check @ operating temp., if it is still low decarbon engine w/seafoam and seafoam deep creep, those engines where lugged alot and will build carbon.
The gauge could be showing a bit low, the cranking speed may be slow, maybe it didn't turn over enough times, which head it has, etc. There are lots of variables. That's why OMC never gave a specific number but rather a range.
I'd have to agree with X -- do a good decarb and test again. I'll bet you're OK.
