I think my XJ650 has a gearbox problem

Tonight on my way home from work, I changed in to 2nd gear and slowly started to roll on the throttle. Just around 4000rpm my 1980 XJ650 (Australian) made some 'clunk' noises, as though it wasn't quite in gear.

I tried to correct it, and settled for another gear. A little later I gently tried 2nd again. Exactly the same problem. Clunk clunk, no real power, clunk clunk...

It doesn't happen in other gears, and is definitely not clutch slip.

Can anyone guess at what the problem is? And perhaps best case and worst case for what will need to be done to fix this?

Thanks

 

start by looking under the shifter cover for loose screws or broken/missing springs
then
either the drive dogs on the gears are rounded off or the shift forks are bent or both

 

Just spoke to my mechanic. He said it's the gear dogs... and it's basically not worth fixing at min $1500 AUD.

 

If you are a patient man you can do the repair yourself at home over the winter (maybe even before winter comes). Do you have a die-grinder or other rotary cuting tool? If not then you can look for a set of good-used gears to swap in.

 

I don't have the mechanical know-how to really do it myself. I could work on it with my Dad - we'd already done some work, and had more planned. The bike hasn't missed a beat until yesterday

It's also currently my only transport.

 

don't give up so easy, look under that shifter cover. there's a cam wheel on the end of the shifter drum that's held on with one screw, if it gets loose it could be the whole problem.
if it is the drive dogs it would only take about a hour to do the grinding and you can hold them in your hand and know if their fixed. if you keep riding it, just skip second and go right to third.
that grinding is doing bad things to the forks and dogs

 

http://www.xs11.com/forum/showthread.php?s=&threadid=5090

http://www.xs11.com/xs11-info/tech-...106-the-second-gear-repair-illustrations.html

here's some links to look at, your motor is different but the gears are the same

 

Thanks mate

 

personally I would look for another engine. swap it in, then try fixing the original.

FU

 

Yea, partially agree with CN....

Drain the oil and pop your covers off. Check out the insides first... Eliminate your easy fixes first.

If it isnt an easy fix.... Look for a motor swap, then fix yours as time permits.

 

That screw Polock is talking about is a Philips head screw that holds a part Yamaha calls the "segment" onto the end of the shift drum. If it's loose it'll tend to rock and not properly shift. if it's broken the previous owner will think the tranny's shot and sell the bike to you for $30.00. (that's how I got my 550)

 

Thanks everyone. It'll have to wait a week or two, but I'll attempt to fix it.