HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
cropduster

03 450 Shift Problems

5 posts in this topic

I'm new to the 450 after being out of mx for 20yrs, I've had the bike for two months and last race I couldn't shift to third or fourth under power. Just putting around and it will shift fine, under power on the track and no deal. The shop has ordered me a shift retention spring, anyone ever had this problem and if so was this the fix, thanks.

Share this post


Link to post
Share on other sites

If you mean that you can't shift under power without the clutch, you shouldn't be able to, and you shouldn't try. But if you mean that you can't shift at high engine speeds, even with the clutch, that is another matter, usually a transmission bearing gone rough.

Can you be more specific in your description of the problem?

Share this post


Link to post
Share on other sites

That's it wont shift with the engine speed up, right? But just putting around is OK?

If that is the case, then it sounds like a problem a guy I know with a 250F had with a bad mainshaft bearing. The best way to quickly check this would be to remove the clutch cover (run up the engine first to scavenge the sump and you won't loose any oil to speak of), and remove the plates from the clutch. Keep them in order, the ones on the ends are a different compound because they run on aluminum parts.

With the bike in neutral, the clutch boss (center hub) should feel smooth, free, and easy to turn by hand (you're directly turning the mainshaft by doing this). If you feel dragging resistance and/or roughness, you have a bad bearing as the cause of the problem.

What this causes is that the bad bearing puts enough of a load on the engaged gearset by itself at speed to make the undercut of the gear dogs hold it in gear against your efforts to shift.

Share this post


Link to post
Share on other sites

I think I found the problem. Switched boots right before the problem started, tried my old boots and shifts good. I am going to the track later and try both the old boots and the newer ones to do some testing.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0