I have this carb on my 270. It has set for a while and the adjustable jet was seized. I removed it to clean it up. What packing seals the adjustable stem when you tighten the nut? I had some gray, lead like material crumble out on disassembly. Also looking for a source for replacement if necessary.
Thanks for any and all responses.
Jeff
"Do not walk behind me, for I may not lead. Do not walk ahead of me, for I may not follow. Do not walk beside me either. Just leave me alone, you're starting to freak me out."
Contact Jon (Carb King) at The Carburetor Shop. He's a member here, but I don't think he accepts private messages. His phone number is on his website. Jon has (or can make) parts for everything since Fred Flintstone put triple carbs on his dino-mobile! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
A number of different materials were used, but felt was the most common used by Zenith.
If you do not have access to felt, try an older hardware store for the graphite impregnated string faucet packing.
OR
If you need to do a carburetor rebuild, the felt is contained in the kit we make.
Jon
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify If you truly believe "one size fits all" try walking a mile in your spouse's shoes! [image]http://www.thecarburetorshop.com/Avatar.jpg[/image]
Thanks for the replies. Are there new adjustable jets available for this carb? Thank you
"Do not walk behind me, for I may not lead. Do not walk ahead of me, for I may not follow. Do not walk beside me either. Just leave me alone, you're starting to freak me out."
You would have to have the identification number of the carburetor, and then check a bill-of-material. It isn't a one-size-fits-all-works-on-none; there are variations.
Jon.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify If you truly believe "one size fits all" try walking a mile in your spouse's shoes! [image]http://www.thecarburetorshop.com/Avatar.jpg[/image]
I'm fairly sure the 1955.2-60 GMC Master Parts Book only lists one adjustable jet assembly for the 1 barrel Zenith carb. Heading out to a graduation party in a few minutes, but I'll look it up when I get home.
Jeff: Where in Hays County? I'm about 10 miles mostly west of Fredericksburg.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/13 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
My brother's over in San Antonio. If I ever come out there to visit I'll have to look you guys up.
1939 Packard Standard Eight Coupe (The Phantom) 1950 Chevrolet 3100 (Ol' Roy) 1956 Cadillac Coupe de Ville (The Bismarck) 1956 Cadillac Sixty Special Fleetwood (The Godfather) 1966 Oldsmobile Toronado (The Purple Knif) 1966 Ford Mustang (Little Red) 1964 Ford Galaxie 500 coupe 1979 Ford F-100 1976 Ford F-150 (Big Red) 1995 Ford F-150 (Newt)
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/13 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
I was wrong in stating that the 55.2-60 GMC Master Parts Book only lists one part number for the Zenith adjustable main jet. That book does not list the adjustable jet at all.
The 1939-53 GMC Master Parts Book DOES lists just one part number for the Zenith adjustable main jet. 2233002. According to that book (see first picture below) it was optionally used on 100 through 350 series GMC trucks in 1939-50.
The second picture shows this part number (2233002) in a "GMC Engineered Accessories" catalog from 1950. There is a very interesting (to me anyway) statement in this document that says "and can furnish normal mixture when the convenient adjustment is turned all the way out". To my feeble brain that means that the original high speed jet is still in place while the adjustable jet is installed. How else would the "normal" mixture occur when the adjustable jet was full rich?
To support my opinion I've included the third and fourth pictures which are taken from a Zenith service manual dated 2-1-61. Item 53 is either a cap or the adjustable jet. Note that there are two parts listed for the adjustable jet, one "used with main jet" and one "when no main jet is used.
I'd like to get CarbKing's opinion on my comment about leaving the original jet in place when the adjustable jet is installed, even if it is that I am full of $#it.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/13 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
Bill - you pretty well summed it up; some of the "adjustable main jets" are complete (different orifices), others are an "adjuster" to lean the mixture of the main jet (still in place). As I posted, not a one-size-fits-all-works-well-on-nothing.
Additional research with the part number of the carb would be involved; plus one needs to look at the carb in question to see if the original main jet is still in place.
Sometimes, folks will replace the main jet with a LARGER main jet, then add the adjuster.
Jon.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify If you truly believe "one size fits all" try walking a mile in your spouse's shoes! [image]http://www.thecarburetorshop.com/Avatar.jpg[/image]
