proper fuel/oil mixture (old rude)

[clay mills]

a buddy of mine borrowed his dad's '59 model Evinrude 10hp. is a 50 to 1 mixture ok? also the engine doesn't run well at wide open. after a few seconds it surges as if you were cranking the throttle from idle back to wide open, over and over. we replaced the fuel line and primer bulb, observed no kinks in the line and even tried it with the gas tank cap removed. milking the bulb seemed to help a little only at idle or half speed.

 

[Yepblaze]

Re: proper fuel/oil mixture (old rude)

It wasn't till the early 60's that 50:1 was recomended for those. Stay with the 32:1. It probably didn't hurt it though.<br /><br />A lean surge could be just the high speed jet needs turning left a bit, partially pluged main jet, or fuel system restriction. If the high speed is adjustable try that first. As I recall some of those lever type adjusters had a small screw that would release the lever and readjust that to the mixture shaft if it doesn't go far enough.

 

[clay mills]

Re: proper fuel/oil mixture (old rude)

thx, yep we'll give this a try

 

[JB]

Re: proper fuel/oil mixture (old rude)

Hi, Clay.<br /><br />OMC recommended 24:1 for the '59s but, as Yep says, 32:1 should be safe.<br /><br />Sounds to me like there is water in your tank or carb bowl. Before fiddling with the mixture, be sure that there is no water.<br /><br />Also, you may have a float/needle problem in the carb. If your problem persists give her a kit.<br /><br />Good luck.