Paul Narramore wrote:I pleased to read others also have problems with carb synchronising. A friend loaned me a set of four gauges, each with a small valve beneath each gauges which I presumed was an anti-flutter valve. They aren't. What seems to happen is that I turn an adjusting screw at which point, the needle stays still, then a tweek of the valve and the needle moves to a new reading. So each adjust has to be followed by a repeated tweeking of these valves.
I have carb 2 and 4 to match No3 (A reading of 4 on the gauges).
No1 though is a pain. No amount of turning of adjusting screw makes a bit of difference and the needle fails to move up or down (A reading of 1.5 on the gauge). Also the revs go sky high every now and again yet pressing down on the screw or it's back plate calms the revs.
In theory I'd like to detach all of the throttle cables from the carbs then the tightness or whatever wouldn't effect the carbs, then once the carbs are adjusted, re-attach the throttle cables.
So far, with three of the carbs reading the same, the bike is misfiring, popping and banging. Rubber tube no2 has an inch or two missing from the end where it goes onto the brass tube, and the popping and banging ejects this again and again.
What's the probability that the oring that seals the #1 carburetor's manifold, to the intake port on the cylinder head, is sufficiently damaged causing an air leak great enough to cause its specific vacuum gauge to be unresponsive to synchronizer screw adjustments?
edit: I reread the complaint again and noted you are tweeking the small valve beneath the gauges quite a lot. A reading of 1.5 never changes on #1. Have you tried switching two adjacent gauges' hookups and observe if that complaint follows the switch?
Maybe the tip of the needle in the small valve is stuck or broken off.
I noted on my 4 vacuum gauge set that if I shut a needle valve completely while the engine is idling, its specific gauge will hold that vacuum reading until the needle valve is opened again.
CliffKeep your eyes and ears open and you'll learn something new, everyday. New users please visit our "Shop Talk" for common tips and help: <---
RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi
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1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
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