Marine: Boating, Sailing, PWC, GPS and Navigation - Chrysler 7hp

Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.



PDA

View Full Version : Chrysler 7hp

DennisG
05-29-03, 01:58 PM
Hey guys, I have an older (1960's?) Chrysler 7hp outboard and I am wondering what the compression should be on it? It measured out at 70psi on my guage....is that enough?

Thanks again!

BoatCop
05-29-03, 05:00 PM
70 PSI sounds a little low. Should be a minimum of 100 PSI, even in an older engine like that.

Spray a goodly amount of Mercury Power Tune or other de-carboning product into the cylinder, turn it over by hand with the plug out and let it sit over night. Then pull it a few times to blow any remaining solution out. Test it again. Hopefully you would have freed up the rings, and will have restored compression.

If it's still low, put a few squirts of motor oil in the cylinder turn it over once or twice to spread the oil and re-test. If it's now significantly higher than it was, you'll need new rings, and maybe a hone job on the cylinder.
DennisG
05-31-03, 09:28 AM
Thanks...will give that a shot as soon as I get a chance and let you know how it pans out.