66 40hp Evinrude Model 40652B running on one cylinder

Milford1971

Cadet
Joined
Dec 12, 2005
Messages
8
Motor seems to run on one cylinder and every so often catches on both, could it be because of wires, they are carbon core? All electrical componants seem fine. Any and all ideas will be checked out to try to get the old twain running good again.:$
 

BoatBuoy

Rear Admiral
Joined
May 29, 2004
Messages
4,856
Re: 66 40hp Evinrude Model 40652B running on one cylinder

If it were mine, I'd do a compression check to be sure it's worth working on. Then I'd check for spark on both plug wires. Carbon core wires don't work well on outboards. They need to be copper core. You can get the wire (7mm) from your local Johnson/Evinrude dealer or a small engine shop.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 66 40hp Evinrude Model 40652B running on one cylinder

carbon core can't take the vibration, yes it could be the problem, could be a coil going bad, and i agree w/ boatbuoy.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: 66 40hp Evinrude Model 40652B running on one cylinder

Yep, get rid of the carbon core wires. You might want to check the points and see if they are in good shape and need replaced. Condensers also.
 

Milford1971

Cadet
Joined
Dec 12, 2005
Messages
8
Re: 66 40hp Evinrude Model 40652B running on one cylinder

Thanks Guys, the wires were on the motor when I bought the boat. Compression is good and all the other electrical parts checked out to spec. but the motor just does not want to fire on both under a load. Remebered reading someone else had a problem because of the carbon core but really did not think it would cause the problem. Will pick up new plug wire this weekend and see if it solves the problem, thanks again
Milford1971
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 66 40hp Evinrude Model 40652B running on one cylinder

what are your compression readings, good don't tell us nothing. when was the last time it was run for any length of time. have the carbs been rebuilt, has a linc and sinc been done. when and what was the last maint.
 
Top