Engine only runs with choke full open

[tmecars]

hello
Im still trying to get my Tricart running properly. After rebuilding the carb, I can get it to start and run fine but it will only run with the choke full open. It has a Tillotson HL283 carb. I have the fuel mixed at 20:1 (which is what these machines called for) but it sure does smoke ALOT. it's definitely running rich.

[liflod]

Full open or fully closed?

If the butterfly is closed and it runs, you probably have a vacuum leak. Check the gaskets and the adapter that connects the carb to the engine.

Could also be a crank case seal that has dried out and needs replaced. Rule out the vacuum leak on the intake side first and then suspect the crank seals.

[tmecars]

Fully open...the butterfly most be fully open for it to run. Is that normal?

[tmecars]

Wait a minute...come to think of it, when I pulled the carb off, the adapter that connects the carb to the engine was cracked! I thought I got it on tight enough but could that be the problem???

[Silverbullet75]

Fully open...the butterfly most be fully open for it to run. Is that normal?

Hi,
When it's fully open, that is the normal running position for carb'd engines. Closed means the airway is restricted, or choked, giving it more gas and less/no air.
You should be able to, when the engine is cold, start the engine fully choked... it'll stumble, fart, and stutter... then slowly open it to full open position. If you are in a warm climate, you may not even need the choke position.
Hope this helps.
If the piece below the carb is broken, that probably is not good and should be replaced.

[tmecars]

Thanks, Silverbullet
I had the theory backwards. Ok, do you think the cracked "flange" could cause the idle to be too high?

[ygmir]

yup,
a vacuum leak can cause high idle, especially if your mixture is rich.

Henry

[cj-ate]

Cracked flange defiantly could be the cause. Crack allows extra air in the mix. Closing the choke (butterfly closed) cuts the normal amount of air, thus causing the engine to run.
Mike

[racerone3]

an easy way to tell if that crack is affecting anything is, with the engine running spray some brake clean, carb cleaner or eather in the area of the crack. if the engine revs up, then it's pulling air through the crack.

[tmecars]

THANKS SO MUCH FOR THE QUICK RESPONSES, EVERYONE. I will spend some time on it and report back. I'm trying to get this thing going (and stopping) well enough to get some video footage.

T