1965 3 hp lightwin only runs with full choke

[Canoe2]

Just finished up a carb cleaning on my motor but it won't run unless it is fully choked. As soon as the choke is adjusted it dies. I'm thinking that it may be the low speed adjustment? There is no high speed on the carb, and i am wondering what my best next step is. I have the low speed out a turn and a half and the motor responds to adjustments, but even if it is running well, as soon as i push in the choke, it dies. Appreciate any advice anyone might have.

 

[Daviet]

Re: 1965 3 hp lightwin only runs with full choke

When you overhauled the carb did you remove the core plug on top of the carb and make sure the little holes in there were clean?

 

[HighTrim]

Re: 1965 3 hp lightwin only runs with full choke

It is still overly lean for whatever reason. Faulty gaskets, air leak at fuel line/fittings, faulty throttle shaft bushing, etc... Number of reasons, just takes troubleshooting to figure out where.

If you back the low speed out more will it smooth out without choke pulled?

 

[Canoe2]

Re: 1965 3 hp lightwin only runs with full choke

Lots to think about there. I think i will start easy with the fuel line fittings - I didn't clamp them down becuase I am swapping parts in and out from another motor so mayeb there is an air leak there causing me grief.I also need to do the core plug and clean that passage. Can i do that without destroyig the plug? I've only ever drilled a hole and then pried it out that way. Happily, I have the entire carb rebuilt done for the other motor so I will swap that in to see what issues it can address. Thanks.

 

[Canoe2]

Re: 1965 3 hp lightwin only runs with full choke

well, I had a better look at my low speed (and only) needle valve. It is pretty misshapen so i think it isn't adjusting the mix anywhere near properly. I swapped it out with a better one and it ran better but still died fairly quickly and i notice some gas dripping from the silencer on the front of the carb. The silencer is a new thing to me; is that normal? My next plan is to take the carb off this one and put it on its twin that I have half torn apart on the garage floor. Come hell or high water, at least one of these is going to run before the snow flies.

 

[Canoe2]

Re: 1965 3 hp lightwin only runs with full choke

well, I had a better look at my low speed (and only) needle valve. It is pretty misshapen so i think it isn't adjusting the mix anywhere near properly. I swapped it out with a better one and it ran better but still died fairly quickly and i notice some gas dripping from the silencer on the front of the carb. The silencer is a new thing to me; is that normal? My next plan is to take the carb off this one and put it on its twin that I have half torn apart on the garage floor. Come hell or high water, at least one of these is going to run before the snow flies.