Evinrude 140 problems ?

[rlguns]

I have a 1979 evinrude 140. got it from a friend who was told it was not worth fixing , it had water in a cylinder , well with nothing to lose i started tearing it down and it was a bad exhaust gasket . it runs fine most of the time but some times taking off it wont get over 2500 rpms but i can stop and high idle it and it goes fine and on plane about 35 mph it cuts out ( sometimes ). well i changed gas and clean carbs . but still does it . I noticed that around the crancase gasket area on the starboard side that when i accelerate it in neutral it puffs air out and i see a little bit of flame . So i think the crankcase gasket is bad .would this cause the bogging and cutting out ? Please let me know what yall think . By the way the compression on the cylinder that had water now is 90 and the one above it is 105 and the other side is 120 and 115 .

 

[JB]

Re: Evinrude 140 problems ?

Howdy rlguns. Glad to see someone who is willing to make an engine run again. With the compression numbers you gave, you have a stuck or broken ring in that cylinder. Run some ring free additive through it with the next tank or two of fuel. It just might clear it up.<br /><br />It is likely that the puffs and bits of flame you are seeing are from a bad gasket on a bypass cover. If the crankcase were loose enough for that to happen at the case junction you would have alloy shrapnel all over the place. A bad bypass gasket will bleed off crankcase compression, which runs your fuel pump, and cause your other symptoms.<br /><br />Good luck.<br />JB

 

[rlguns]

Re: Evinrude 140 problems ?

rings look good and are not stuck . going to replace gaskets on bypass covers and spray engine tune in the cylinders to see if that helps . Thanks