Vacuum plugging

Scott Nutter

Scott Nutter

New member
No not that void that is left when the hot chick leaves the room...

Has anyone plugged the vacuum tubes on the base of the carb with something other than rubber boots? I was thinking solder or brass, not sure about solder's melting point. The reason I'm asking is that I've got my carb in pieces in the basement because of a nagging loss of power at the end of long straights last year. Of course my car will be running with one of the stock carbs from my parts bin cause this one will never work again :).

Is this legal?

Anyhow the rubber boots where pretty cracked and I would hate to have an unchecked vacuum leak.

Any thoughts are appreciated.
 
The black rubber caps sold as vacuum line caps in the parts stores just don't last on a rotary. They harden and crack from the heat. I have much better luck with the vinyl caps sold in hardware stores as thread protectors.
 
Thanks for the responses. Has anyone use that quick steel epoxy putty to fill the vacuum lines? I would just like a more permenant solution, I did toast a motor once due to a vacuum leak and I still don't check them often enough.
 
If you want the most permanent solution you need to braze them closed. Epoxys can work loose over time. I'd trust the silicone caps over an epoxy.
 
Scott Nutter said:
Any thoughts are appreciated.
Click to expand...

Hiya Scott!

Another vote for the silicone. I wrap a small zip tie around each one also.

This is going to sound strange, but try running more fuel in your tank. For some reason, my stock tank used to run out of fuel at the end of the back straight at Mid Ohio. If you're still running Pat's old car, I think it suffered from the same malady. Car would be fine everywhere but the end of the straight. Seemed wrong, but more fuel always fixed it.

I won't cover the fuel pressure, fuel pump, float level, blablabla. Sounds like you've been chasing all of that already.

Didn't that car have a Yaw carb on it? If so, I can dig mine out and verify what jetting it used to like.
 
Hi Dave!

How's your racing been?

Yes I'm still running Pat's old car and it has a Yaw, but I never had a problem until this year...Maybe I'm getting faster:) ...Probably the car is just getting older :(

My first go around was more fuel, and it seemed to work for awhile. Then I started getting it after a good run out of the carousel @ Nelson and of course Road Atlanta @ the ARRC was horrible.

Silicone it is for the caps.

Next question. Do I use loctite on the jets and all those other little brass doodads? They did not seem very tight upon disassembly, but snug.
 
also check the float level and clearence to the baffle in a yaw carb. Mine expandedover timeand actually lowered the float level. new baffles and a rebuild cured it. While it was apart we welded the ports closed. Very low heat and speed on the mig,and practice on junk first
 
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