61 Evinrude 40HP Won't throttle up, Please Help

[wtwick]

I have a 1961 Evinrude Lark IV engine. It starts and idles, but when you advance the throttle the engine sputters, runs jerky, and won't throttle enough to plain the 14 foot boat. It seems to be fowling the plugs because after being run for a while it wont restart without drying the plugs off. I've tried adjusting the low speed idle valve. This model has no high speed valve. Any help on this matter would be greatly appreciated. No one in my area will work on this old of an engine. Thank you.<br /><br />------------------<br />Wtwick

 

[adrian bick]

Re: 61 Evinrude 40HP Won't throttle up, Please Help

Test your ignition coils. The spark MUST jump 1/4" in free air, Under compression it takes a lot more to fire a plug. These motors were well know for coils aging and cracking.Coils are not expensive. Good luck

 

[wtwick]

Re: 61 Evinrude 40HP Won't throttle up, Please Help

Thanks I'll check the spark. I think the cole should be ok though, it was replaced three years ago when the engine was rebuilt. Could it be anything else like fule system problem?<br /><br />------------------<br />Wtwick

 

[kyriakos@baynet.net]

Re: 61 Evinrude 40HP Won't throttle up, Please Help

I had a similar problem with my old 33. It sounds like you may have carburation issues. One of the easiest things to do is take the carb off and clean the thing very well. I took mine off and all apart and blew out all the ports with compressed air. This helped things out tremendously. A quick adjustment would be to adjust your mixture on the fly. If you are getting too much fuel, which it sounds like you are, turn the mixture adjustment screw clockwise and hopefully the stuttering stops....Otherwise clean it. Good luck!!

 

[wtwick]

Re: 61 Evinrude 40HP Won't throttle up, Please Help

Thats what I was thinking, carb problem. I'll get a carb kit and see if that helps. I had tried to adjust the lean on the fly but it didn't help. Whats good to clean the carburator with. <br />Thanks Wayne<br /><br />------------------<br />Wtwick