1974 Johnson 25 hp

[JohnAB]

What is the compression supposed to be on one of these critters?<br /><br />Checked mine and it is at 70 lbs top cylinder, 68 lbs bottom cylinder. Seems low to me.<br /><br />Added some 2 stroke oil to cylinders and pressure did not change appreciably.<br /><br />I know motor definitely needs a Seafoam job.

 

[JohnAB]

Re: 1974 Johnson 25 hp

Oops should have mentioned motor runs fine, purrs like a kitten except I believe it is running a bit rich unless with those compression numbers that I am not getting a clean burn of fuel.

 

[DJ]

Re: 1974 Johnson 25 hp

JohnAB,<br /><br />Sounds good to me. The important thing is that they are very close to each other.<br /><br />Do a decarb and enjoy the engine.<br /><br />Read this.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000006 <br /><br />Don't forget to replace the water pump and service the lower unit!