Carburetor jetting, Recommended base line jets for Weber 40s Options

[Slanski62]

Hello. I'm new to the forums here but have been reading and learning a lot. Thank you.

I have a pair of Weber 40s I plan to use on a 2056 I'm building. The carbs are used, and I don't know how they're jetted. Can anyone recommend a base line? I'm at an altitude of 486 feet. I appreciate any suggestions!

Steve

[jmill]

You'll know if it has ethanol in it. There'll be a sticker on the pump that says something like "up to 10% Ethanol added".

Carb pops are usually caused by a lean condition. That means vacuum leak, clogged jets or jets too small. They can even be caused by an improper linkage or bad linkage setup (not synced).

Assuming you have mixture screws properly adjusted
1- check for vacuum leaks
2- check out linkage
3- clean idle jets
4- step up idle jets (as said, 47's are on the small side)

Exhaust pops have a few causes.

Again assuming mixture screws properly adjusted
1- check for exhaust leaks
2- adjust valves
3- idle jet too small