1979 evirude 15hp carb problem?

[Elliomcmh]

Hi, I have a 1979 evinrude 15hp, mounted on a 1965 alumacraft 14ft. F-7. I am having some problems that might or might not be carb related. The motor cranks and idles great after it warms up. But it kind of bogs down alot when I give it full throttle. It also bogs down when If it's at full throttle and I move it to half throttle then try to throttle it all the way up again. All in all, it lags just about any time I apply throttle.
It also does not seem to be hitting top speed. I can barely get The boat to plane off, unless I ease the choke out just a little while at full throttle,but even then it takes a long time to plane and still doesn't reach full rpm's. I replaced the plugs just for the heck of it. I just bought this boat and motor, and really like it except for these issues. Any suggestions?? Thanks

 

[ONERCBOATER]

Re: 1979 evirude 15hp carb problem?

since choking appeared to help , i would guess you have either a weak fuel pump or clogged high speed jet.... that said try pumping the primer while accerating and if that helps look at fuel pump... my best guess is high speed jet though as with weak fuel pump most times will accerate well then fall on face. Also when done with carb cleaning suggest you do link and synch.... betting you will have great performing engine. One last thought as it crosses my mind.... check spark on both plugs and compression.... the darn twin cyl can idle wonderfully and run remarkably well on one cyl.

Sean

 

[Elliomcmh]

Re: 1979 evirude 15hp carb problem?

I tried squeezing the primer bulb, and it really didn't help.. I am going to order a carb kit, service manual, and clean out the carb. And I will also check compression and spark, thank you so much for your help

 

[cr2k]

Re: 1979 evirude 15hp carb problem?

Have you done a compression check? Are both cylinders able to produce power? Spark to both plugs?
Is it overheating?