flathead carb issue

jbiros

New member
What would likely cause high idle on a a methenol flat head... cant back the idle adjustment out far enough for it to turn the idle down..... had to borrow a carb to finish the night.
 
Remove the jet.
Check to see if both holes behind are open. Do not use a torch tip cleaner to open.
What did gasket and carb flange look like?
Diaphram, maybe.
Check tube screens in fuel tank. Check cap vent.

Engine is lean at idle. Methanol engines generally need to be rich at idle to run properly, using the very basic carbs required by rules.
 
What would likely cause high idle on a a methenol flat head... cant back the idle adjustment out far enough for it to turn the idle down..... had to borrow a carb to finish the night.

Make sure the tiny spring on top of the butterfly didn’t become undone
 
Very well could be an air leak.
With the carb & tank bolted in place, start the engine and let it idle (as best as it does), then spray some starter fluid (or WD40) around the gasket areas and the top of the throttle shaft. A definite change in engine rpm will denote an air leak that needs addressed.
That spring on top of the link from the t'shaft doesn't do a thing (other than keep tension on the t'shaft to keep it from wearing the bushing.) I strongly recommend using it for this reason, but it is not required, or even a tech item.



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Vector Cutz
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I double them up at the intake and tank and glue them together with permatex copper spray inside and out. Works like a champ(y)
 
^ Technically, that is illegal.
Per rules, no sealants are allowed on the flathead gaskets.
It would take a pretty picky tech man to toss you on that specifically, but it is in the rules. :)
If it were something that could be a potential performance increase, it should be called in my opinion. (ie sealant protrudes into the port, etc.)
 
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