Sneck, BRILLIANT! To my eyes this is a marvelous revelation.
When I read Bobber's suggestion to check the weights I had a moment of skepticism, but I have to say that this is such a wonderfully unexpected observation that it's spurred me to begin checking weights. Our ..."jobs" as professionals, so called, makes us acutely interested in any variable that we can anticipate and thus eliminate. I'm truly awed that you actually found a heavy float, which naturally is going to be less buoyant and tend to overfill. Bravo to bobber for asking and to you for not being an "expert" (read: assumption-making know it all)! Of course this could eventually be rejected as the root cause but it's invaluable nonetheless. Either or both of you get a set of new pilot needles for your efforts. PM with your info (or use firstname.lastname@example.org
) and I'll send them out.
RE, overflowing, let's be clear on the symptoms.
A weeping float, whether due to seat, needle, or **soggy float(?)**, will fail to seal off the flow of fuel into the carbs. With nowhere to go the gas level will rise to the point where it will 1) reach the top of the overflow standpipe and run out through the drain tubes or 2) exit upwards into the throat of the carburetor and from there will obey Newton's laws of gravitation. I've seen both inundated air cleaners and gas-filled combustion chambers. Which scenario depends on how the bike is situated. Resting at a critical incline will locate the top of the standpipe higher than the next lower point of exit and you'll have a catastrophic leak.
A cracked standpipe, on the other hand, will weep fuel out through the drain tubes and NEVER rise into the throats by simple reason of the fact that the bowl is draining before the float lifts far enough to shut off the flow. Think: leaky toilet.
Gas in the throat(s) eliminates the standpipes by default. (This is NOT to suggest that one should fail to verify their soundness as a matter of course--one could be clogged OR cracked.)
If I could prevail upon you to run one more simple test, leave the heavy float in the sun and see if the weight decreases. This will tell us if there's fuel inside or if it's simply defective.
Thanks again for being such an adventuresome sort.