1977 evinrude 140

[me again]

ok it runs great idles smooth goes in gear plus rev out of water.once in water its a dog wont get out of the hole.some times falls on its face.hard to start sometimes.but if i get it going long enough it will plain out and goes like hell ? im lost on this one

 

[me again]

Re: 1977 evinrude 140

anyone? is it a prop problem?posibley a fuel pump or power pack? like i said once it plains out runs fine.takes aloooooooong time to plain out though. its on a 89 bayliner capri 17 ft if makes a diffrence

 

[emdsapmgr]

Re: 1977 evinrude 140

That engine will seem to run just fine when on the trailer. Does not take much hp to idle with no load. It could seem to run fine and only be running on 2 cyls. Once you put it in the water and get some real exhaust backpressure, it needs 4 cyls to idle well. You may not be firing all 4 cyls. Check for spark on all 4 plugwires using an inductive timing light. The flashes from the gun will show you if you have misfires, weak firing, etc.