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Carbs again

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6

69tr

Jedi Trainee
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I bought 2 used carburetors from Team Triumph (1973 model)and 2 rebuild kits from Moss Motors. When I removed the bypass valve to replace the gasket I found that the gasket in the carburetor was solid so as to blank out the holes in the valve. The ones in the kit had an elongated hole to allow passage between the holes. I have heard that the difference between the '69 and the '71, besides being able to adjust the '71, is that one is external vacuum and the other is internal vacuum. The ones that I bought have what looks like a large vacuum port on each carb and one small vacuum line on the bottom of one of them. The ones that are on the car do not have the large ports, Only small ones for the vacuum advance.

Can someone help me out?

Thanks, Pete
 
Not sure I understand the question, Pete. Using the wrong gasket in the later carbs is sometimes done to disable the bypass valve (which most people feel is just a nuisance). With the earlier carbs you can just disconnect and plug the external vacuum line to the valve.
 
Just to be clear since you have mentioned buying 73 carbs yet seem to be refering to 71 carbs. Which ones are you asking about ?
If it's the 73's then you might be asking about the Anti Run-on Valve/ idle speed float chamber vent nipples. They are on the left side of the carbs, close to the carbs' air box mounting flange and they point toward the cockpit ?
 
Randall is correct. The diaphragm over time can develop a hole causing a high idle that just can't be adjusted down. The options are blanking it off or replacing the assembly(the '07 price I'm looking at is in the $85 range /each). If you can round up two good used valves, great. The other part of the high idle fix is to run the nyloc nut in the temperature compensator down snug. Check the nut before making your decision on which direction to go.
 
If it's just the Throttle Bypass valve Diaphram that need replacing, you don't need the whole valve assembly, just the diaphram kit which also includes the gaskets; about $12.00
The temperature compensators don't allow fuel to enter the carb, on the contrary, they act kind of like a mini choke in that they restrict some air from getting into the mixing chamber until they open up, at which time they allow whatever amount of air that can get thru a 1/4 inch diameter hole into the mixing chamber of the carb. It's really hard to hear the difference between a closed and an open temperature compensator port.
 
I was told thatt he carbs that I bought are from a '72 or '73. They have the 2 large vacuum ports on the top of the throttle body and one small port on the bottom of one of them.
When I removed the bypass valve the ports were blocked with the gasket. The kit I bought has an elongated hole to allow passage between the ports.

The carbs on my '69 have 2 small vacuum ports on near the mounting flange. I don't remember what the gasket looked like when I rebuilt them a coupe years ago. I might need to remove one of them and take a look.

Sorry if I did not explain this very well. I aint vury artikulate.

Thanks, Pete
 
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