1962 40hp runs rough at mid speed

johnnyvelcro

Cadet
Joined
May 20, 2009
Messages
8
I have a 1962 40hp Electric shift that runs terrible at mid speed. idle is ok, high speed is ok. WTF?
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,762
Re: 1962 40hp runs rough at mid speed

I've been plagued with the same symptoms, revs up great gets on plane but to back off a bit to find a nice cruising speed and she runs a little rough, classic carb symptoms, I was trying to find out what size orifice plugs (high speed jets) are supposed to be in there but can't find data another thing I was looking closely at is play in the distributor shaft and rate of timing advance, have you performed link-n-sync? Hopefully you get some good input beyond the basics, I'll be interested.
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: 1962 40hp runs rough at mid speed

carefully check the plug wires. I'm wondering if a wire is going to ground as the stator plate rotates, or advances. On an engine that age, check the coils for burn holes, or cracks.
 

johnnyvelcro

Cadet
Joined
May 20, 2009
Messages
8
Re: 1962 40hp runs rough at mid speed

Carb is clean. Did adjust linkage for spark advance and got much improvement. I think I'll leave it alone now. Can't expect perfect for a "62. Thanks guys for all your help.
 
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