carb kit - 3hp 1968 evinrude lightwin

film495

Petty Officer 2nd Class
Joined
Apr 8, 2009
Messages
149
So - I have never done a carb kit on any motor before and am a little worried about it, but I've read here long enough to see that should really be done on my 40+ year old motor. I got a carb kit at the local NAPA, but it did not come with a float - so, I'm not sure if I'll end up treating the original one with epoxy and putting it back, but I'll find out. The motor starts and runs fine for about 45 minutes - then it seems to die and is very hard to restart. On this restart it runs like poo and required the choke out to keep running and then will stall out again in a couple minutes. This time pretty easy to restart and runs fine - don't need the choke out - so, there is something screwey in there so - I'll going to pull the thing apart and clean it and try to reassemble. Please give me tips - I read that the setting is 1 turn out for the high speed needle and 1.5 for the top low speed, but I'm pretty sure I'm going to do something wrong on this and am hoping somebody who's already made that mistake can hook me up and save me some hair pulling. I also already read through the Top Secret files.
 

film495

Petty Officer 2nd Class
Joined
Apr 8, 2009
Messages
149
Re: carb kit - 3hp 1968 evinrude lightwin

gas was squiring out the throat after I put the new carb kit on - I just used a heavier gasket/ring from the kit and put it back together and it was hard to start but, seemed to get up and run OK and tuning it was not an issue. Seems to run cleaner/smoother - we'll see if I have solved the mysterious cutting out issue. Thanks for all the info on this site - I would never have tried this without this resource.
 

film495

Petty Officer 2nd Class
Joined
Apr 8, 2009
Messages
149
Re: carb kit - 3hp 1968 evinrude lightwin

It was interesting when I took it apart - 1st and 2nd time, the high speed adjustment had gas come out of the needle fitting - so, I'm not 100% sure, but as far as understanding what the mechanical function of the 2 adjustments is - the rich/lean seems to affect the flow of gasoline and the slow speed adjusts the air?

I'm not sure, but I think I've seen a few people ask that same type of question on here. It is not really relevant to making the settings correctly, but for people who like working on their old motors, what these 2 needles actually do inside the engine is of interest; certainly I found it very interesting that gas came out the high speed needle fitting when I started taking the carb apart.

I've been spinning those same knobs since I was 10 - and 25 years later, now I have some idea of what they do; I think that's pretty fun. Hopefully, the kids will get a kick out of the old boat and motor come 4th of July this year.
 

harkerr

Cadet
Joined
Apr 29, 2009
Messages
7
Re: carb kit - 3hp 1968 evinrude lightwin

I had strange problems with quitting after warming up on my 3hp. It was the magneto coils. These old coils are notorious for breaking down. You can get an in-line spark checker from Harbor freight for less than 10 bucks. Put in series with each plug and see if you are losing spark. The motor will run very poorly on one cylinder. If you lose spark, you will have to change the coils. Check Wholesale Marine for Sierra replacements. See manual to change. Flywheel puller required, but not a tough job.

Good luck.
 
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