Quote:
Originally Posted by Triple Jim
The are easier ways to make it a little richer at the stumbling point for test purposes than shimming the needles. Also safer for the diaphragms. One is to use the starter lever. Another is to temporarily put some tape across the filter or filter box inlet to block a little air flow.
|
Thing is, choke is fixed amount of fuel. The higher and higher engine revs, especially under load, the less this additional fuel contributes to overall AFR.
It's not a valid test to turn on choke to see if 9K-rpm stumble from lean mixtures goes away, because it will not. Simply not enough additional fuel at 9K-rpms and +100% throttle to change AFR.
Conversely, if choke really did add sufficient fuel to fix 9K lean spot, on perfectly working bike, turning on choke will cause it to stumble at 9K from being too rich on other side of stoich. We know that this doesn't happen, as we also know it doesn't fix 9K stumble from lean mixtures either.
Yeah, tape up half filter test, will just make bike slower. Won't stumble though. You have to replace filter with one that actually stumbles,
then do testing with modified AFR to see which way, richer or leaner, removes stumble.