Inlet manifold, or carb bushing leakage, causing engine to run lean.
Check spark plug colour - this may indicate it is running lean, although this may only be occuring at low throttle settings so it may not be apparent.
This occurs as at full throttle, you have low vacuum, so leaks are not really apparent. But at low throttle, or with choke on, engine vacuum is very strong, and only a small amount of extra air will cause extreme lean mixture.
You can look for this as follows :
Buy a can of ether - like "start ya bastard".
With the bike idling or as close as it will get to idling after a long run, spray all around the carb, and inlet manifold. Dont spray near the aircleaner Intake, just all around the carb and inlet manifold. A sudden increase in RPM indicates a leak.
This may be a manifold leak, or a dodgy bushing or seal on the carb.
David must play fair with the other kids, even the idiots.
Bookmarks