Johnson 150 Compression

[Huntoon]

Hi Folks,<br /> <br />I'm considering a deckboat with a Johnson 150, year 2000. Compression test is 1-100, 2-95, 3-105, 4-95, 5-110, 6-100. <br /><br />I've read that below 100 could be a problem, but also that maybe that's OK with a V6 and also maybe OK if all cylinders are within 15 (particularly on the same side).<br /><br />The engine runs fair -- might be months from last run and might need carb overhaul.<br /><br />What do folks think? Thanks!

 

[JB]

Re: Johnson 150 Compression

Howdy, Huntoon.<br /><br />Welcome to iboats. <br /><br />I see you've done your homework. Yes, the compression numbers are marginal, but inside the envelope.<br /><br />She probably needs a good decarb. You need an on-the-water test to tell much about the carbs.<br /><br />Good luck.

 

[ob]

Re: Johnson 150 Compression

Make sure the engine is propped to turn in the upper end of its recommended WOT range.Say 5800.If overpropped and lugged ,it will lead to coking problems.I agree that the compression numbers look acceptible.If I'm not mistaken,it is common for some of the V-6 engines to produce lower compression numbers than say,130 to 135.One of the pros can confirm.

 

[walleyehed]

Re: Johnson 150 Compression

I ain't no pro, but 100lbs. on a std V6 is very acceptable.

 

[Dhadley]

Re: Johnson 150 Compression

Especially on a 60 degree V6. Those numbers are just what we'd expect.<br /><br />Good luck and welcome!!<br /><br />PS -- Kenny is a pro. Dont let him kid you.....