first gear slipping

[robichjr]

I'm about to dive into my old bike, tear it down and build it back up. I've got a 1987 250 X that has plenty of work to be done on it. Anyway, a few years ago I had it worked on because of the common 3rd gear slip. After I got it back from this shadetree mechanic, 1st gear acted like 3rd gear did prior. Well, I was a kid and didn't care, so I just never used 1st gear.

Now I want to do it right. I am suspecting a worn or bent shift fork. Is it a good possibility that I am headed in the right direction, or am I barking up the wrong tree?

Thanks in advance for any replies.:)

[RIDER11X]

Ahhhhh, the ole' 250x. I had one and loved it!

Anyway, what kind of oil are you running. Automotive oil does those trannys no justice. Make sure you have good motorcycle oil in it. Mine shifted much better with Honda HP4 in it. BIG DIFFERENCE!!!! It takes up to an hour of riding for it to work into the clutches well.
Then if that don't work check your clutch for problems. First gear will show probems like this easier than other gears because it is more abrupt. Try this and post your results if you would. Hope this helps.:cool:

[robichjr]

I can't remember exactly which one, but I know it is a synthetic motorcycle oil. I'll try an oil change, but the engine's got to come apart because of old weathered seals.:( Thanks for the suggestion, I hope it works. If it does I won't have to split the case.:D

[phatswinn]

try some mobil 1 full synthetic but make sure there arent any friction modifiers in it that will mess ur clutch up, if used the oil for years and its done wonders