1965 40 hp big twin

[freddybell79]

runs kinda rough at idle. and bogs down when trying to go full throttle. im thinking maybe carb needs rebuild but Im no expert. also seems like it throttles up pretty good in reverse. I dnt understand. HELP

 

[Tim Frank]

Do the triple threat.
Check compression, check/verify spark, and then what's left is fuel.

 

[freddybell79]

I have checked spark. note to self. it hurts like hell when its firing good lol. haven't really checked compession as u actually should. done the old shade tree way. hold finger over hole. that's why I figure its fuel.

 

[F_R]

Throttles up pretty good in reverse, huh? Actually, it shouldn't. It sounds like you need to do a thorough inspection including a real compression, ignition, and fuel system checkup. Spark and shock doesn't mean much except there is hope. You have to remove the flywheel to do a decent check on the ignition. And don't forget link & sync.

 

[freddybell79]

compression 110 on both cyl. possibly out of sync. I noticed the lean/rich fuel mixture adjustment not working any more. has spark. has compression. have changer plugs wires and one coil that had went out.guessing fuel related. ordered rebuild kit

 

[freddybell79]

I really know nothing about boats. seen other threads where it cld be points or coils but its got spark. frustrated