Ari Rankum
NAFO Karting Champion, 2012
There's more. Apparently, there is some internal engineering research that Yamaha have just barely failed to keep within their walls. From a document called Yamaha Operational Worksheet, Internal Engineering #2006-23, a "sympathetic vibration occurs in the primary drive train as shifting speeds approach a resonant frequency at 5.5 shifts per second." Later in the document, "though not likely to occur under normal use, recent evidence has been uncovered that suggests at least one #%$*@! is shifting his AE 5.5 times per second." And, finally, "therefore, for the protection of all of the other customers, the appropriate step would be to issue a technical service bulletin (TSB) requiring updates to the actuator componentry at Yamaha distribution points."Probably this mounting system is not stout enough to take the back-and-forth hammering of the shift rod linkage. For instance if you pull to a stop light in 5th gear and start downshifting to 1st while sitting still the shift rod and actuator might take a bit of a beating.
Last edited by a moderator: