Zenith 2 carb
 

is the inside diameter on the cap, main & idle jets all supposed the same?
The 'A' sat for a long time; I inserted a paper clip thru them to clean & have been experience backfire after running temperature is reached.
Thanks.

Re: Zenith 2 carb
 

If you could run a Paperclip through the jets then the opening is way to large on all the jets. As a example, a original idle jet will have a #11 and is usually .021 orface, the comp. jet is usually a #19 .037 orface. All original jets are numbered; replacement jets are not numbered, and some of them are junk.

Your Zenith-2 indicates it was built by Holley Co., providing it has a Holley Top. The Zenith-1 was built by Zenith Co. They both use the same jets.

Ron

Re: Zenith 2 carb
 

REVISION! I was not happy with the readings I got last night in the cold, and with a vernier. Tonight I went back in to do the job right. After screwing around with a couple of carburetors until I got one I could get the butterfly screws out of and remove the throttle shaft. I miked it with a micrometer, not a vernier. Shaft Dia. was .279, that's more like it! I then stuck a 9/32 (.281) drill blank into the bore and shook it around. It was a good fit and I estimated about .001-2 slop so the bore size is .2815-.282 with a shaft dia. of .279 is about .0025 to.003 clearance. I, myself wouldn't bother with oversize shafts or bushings to gain what? Sorry for the confusion last night.
Terry

Re: Zenith 2 carb
 

See attached document. Pages 12 and 13 addresses jet sizes.

Tom Endy