Johnson 88hp compression reading

[DBLD]

Hello,<br /><br />I am looking to purchase a 1994 Johnson 88hp outboard. I want to take a compression test, but as I do not yet have a manual for this outboard, can someone tell me what the range should be? <br /><br />Also, should the test/reading be done when the engine is hot or cold?<br /><br />Finally, any info (good or bad) I should know about this engine? THANKS!!

 

[Luna Sea]

Re: Johnson 88hp compression reading

Hi, welcome to the forum. As far as checking for a new purchase, hot or cold shouldn't matter much. Numbers aren't all that important either, should be up over 100 but the big thing is if they're all within 5 or 10(max) percent of one another. Good luck. You can search on here and find more info, all you need. Happy Holidays

 

[DJ]

Re: Johnson 88hp compression reading

Luna Sea's got it right.

 

[Luna Sea]

Re: Johnson 88hp compression reading

Thanks djohns19! And I learned it all right here. I was in his shoes asking the same question 6 months ago. Happy Holidays everyone!

 

[Waterbugtoo]

Re: Johnson 88hp compression reading

Lemme also add that using 10 different compression gauges will give you 10 different results as to why there are no specific numbers on what compression should read on any given motor.<br /><br />

 

[miloman]

Re: Johnson 88hp compression reading

some other things you should do I would pull the drain plug check the oil if its milky look out if it is discoloed fine if it smells burnt look out if its new I would ask to do a pressure test you can do this in his driveway if hes fine with it. pul the plugs look for condition wet ok white or dry look out as for the compression test of the top of my head it should hold 11psi for 30 minutes you can do this easily lots of post here as to how am I right guys would also be nice to do a vacum test ask for any recipts or the marina he had it serviced at check it out I mean its not a huge investment but $1 wasted on a bad motor is a bugger