40hp Evin. Carb Swap??

[Low Water Nut]

Hello,<br /><br />Was wondering if anyone could shed some light on swapping carbs from a 50hp to a 40hp Evinrude.<br /><br />I have a 50hp parts motor with a burned piston that I was using for parts. I have a 40hp currently on the boat. There is a Jet Unit on the motor which is really only putting out 28hp with the 40hp head. I would like to know if the carbs from the 50hp head will fit up and work without any problems? If I can get the 50hp carbs to run on the 40hp that will give me almost 35hp at the jet.<br /><br />Motor Info:<br />40hp - E40ECEC<br />Serial # G02279961<br /><br />50hp - J50JETB<br />Serial # G03252905<br /><br />I am positive the 40hp is an 1989. The 50hp I think is 1993?<br /><br />Thanks for any advise or help with this!!!<br /><br />Aaron

 

[surlyjoe]

Re: 40hp Evin. Carb Swap??

well, if theyy are both big twins,, the carb will bolt on, but I would guess its the same CFM as the 40hp carb. the carb has very kittle to do with power unless its restricting the motor. all a carb does is mix the fuel to the proper ratio of air. a bigger carb will not get any more mixture into your motor, horsepower is dependant on displacement and compression/stroke, and port placement and other stuff like combustion patterns. the carb just mixes as much fuel/air as the engine can gulp.

 

[Dhadley]

Re: 40hp Evin. Carb Swap??

Welcome!!<br /><br />You are correct on the years. The carbs will swap, no problem. With a jet you might see a slight improvement, maybe not. The real difference in the two is the reeds. Specifically the reed stops. The stops on the 50 are open a bit more than the 40. Using the 50 carb and reeds may help.<br /><br />If it were mine and I was going to do all that, I'd just stick in a set of Boyesens and be done.