250s stalling

[Labadie250s]

when the engine is cold the car tends to stall at the first few red lights. So lest say I'm pulling up to a stop sign, I shift into neutral and then brake and the red light comes on and the car stalls. Now If I'm careful I can let up on the brake and rev the engine a little and it comes back to life. I assume this is a vacuum leak? If so how do I hunt down the leak?

[Skippy]

On my 250, the chokes open way too soon, making stalling a bit of an issue until it starts to warm up. You might want to check that on yours.

[mak]

there is a cold running idle adjustment screw to adjust if not to specs . this is visible when you move the throttle to the full open position and it comes up.
normally its the idle bleed jet getting clogged . A squirt of carb cleaner in the small intake hole on the carb top suffices.
Among others, JC Whitney carries a excellent carb synchronizer ,German make for 30$ or so. i got it about 30 years back and its still available !!
mak

[Layton]

I purchased a Bayou 250 in January of this year. It has been back into the shop three times now because it consistently stalls on idle, even when warm. Assuming the idle speed isnt too low, it could be a low or high float level, dirty air filter,partially plugged idle jet, misadjusted mixture screw.

[axdrikqwbn]

I accept with information:there is a cold running idle adjustment screw to adjust if not to specs . this is visible when you move the throttle to the full open position and it comes up.

[ja17]

Hello,

There are very few mechanics left who know how to set up these Zenith carbs. Setting up the linkages, adjusting the chokes, and making sure the carbs are functioning like they should will usually solve the problem.

Often times one of the small idle jets will be plugged in one carb.

Yes a vacuum leak can also cause issues. The gaskets at the base of the carbs shrink and leak air from age, heat and inactivity.

Make sure the car is in good basic tune and the compression is good on all six or you will just be wasting your time.

There are some good instructions on line for these Zenith carbs. The Zeniths on the early models like your 250S are the best. They do not have the added emission devices found on the later cars.

These carbs are complex, but when put right, they work well and are trouble free.