the gear dogs did have wear on them when I rebuilt the motor and trans. the shift fork pins were also below minimum specs. I couldn't find new replacement forks because they are discontinued and buying a crap ton of shift forks to find good used ones in spec didn't seem to be cost effective. I am not sure when I'll be able to ride it again. I know in august will be my next chance. where would I find gears and forks if it is indeed the trans dropping out of gear? and if I have to tear it back down, I will be sending my spare 300 big bore out to get repaired.
my 500 was doing exactly the same thing a little over a year ago...the main problem was a busted snap ring, a snap ring that was only 4 months old....I could run it hard through the gears, and once I clicked into 5th, within a couple seconds it would jump back into 4th...and scare the f**k outa me cause the rpm's went way too high.
Once I got it pulled apart, I also found the forks were worn, 2nd-3rd-4th-5th gears were all worn...the drum had some wear....there were a lot of things that contributed to it failing. So at that point, it made more sense to just replace the entire tranny and shift mechanism...as I had no interest mating new parts to old parts.
I know it may not be the best choice financially, but it might be easier to find a newer year motor where parts are more readily available...or...find a 500 motor and stuff it in there!
Either way, keep us posted...and good luck.
