74' Johnson 25hp Compression question

[commosmart1]

My engine is fouling out brand new spark plugs within a few hours. I my gas/oil ration is good and I checked the compression and one cylinder is getting 123psi. while the other is getting 75 to 85 psi. Any ideas and what I should do?

Thanks,
William

 

[SparkieBoat]

Re: 74' Johnson 25hp Compression question

go to secret files section and find the decarb instructions...if that does not work remove your head cover and see whats up..

 

[wilde1j]

Re: 74' Johnson 25hp Compression question

I would pull the cylinder head and hope for a blown head gasket. Let us know what you find.

 

[commosmart1]

Re: 74' Johnson 25hp Compression question

Thanks can you give me a link to the secret file section, I cannot find it on here.

 

[jbjennings]

Re: 74' Johnson 25hp Compression question

I woulde pull the cylinder head and hope for a blown head gasket. Let us know what you find.

Good advice above, here's the link: http://forums.iboats.com/showthread.php?t=299680
Good luck,
JBJ

 

[samo_ott]

Re: 74' Johnson 25hp Compression question

I would pull the cylinder head and hope for a blown head gasket. Let us know what you find.

I would also do this.

 

[boobie]

Re: 74' Johnson 25hp Compression question

Way to much difference in compression readings. As suggested above, pull head.

 

[kenmyfam]

Re: 74' Johnson 25hp Compression question

Agree with all the above. Whip off the head and check things out. For the cost of a gasket it is a small investment that can tell you so much.