1981 xj650 4KO (uk model) rebuild @ 32k miles

Apologies for my confusion on differing threads. Firstly, I did have the engine apart to change the primary drive chain.
It now transpires I had 2 problems,
1- Rear wheel binding, but gave it a first test run, (didn`t have the the axle spacer at this point), it made the very nasty grinding gears noise when selecting second gear. (rode the short distance home in first gear)
2- after the spacer was fitted, and wheel turning nicely with no binding, the second test run resulted in grinding reappeared as before (when selecting second gear), but this time the transmission locked completely. had to push it the short distance home with the clutch pulled (still very hard to push).
k-moe suggested a clutch issue after the first run, but first gear engaged and pulled away as normal, so I though it was good. I am planning to take the clutch casing off tomorrow. I hope k-moe is right (what I have read so far, he usually is), or this could get expensive. Never mind, it will be fixed in the end, the help on this forum keeps me motivated, massive thanks to all!

 

Nil desperandum my friend. Stick with it, you have one of the best looking xj's made. There are loads of used bits around so whatever is wrong can be fixed. If I

 

As in split cases, and was that the guide breaking up?

This thread is similar, but had a broken guide and after repair they had a lockup in 1st, which was attributed to not finding all the chunks the first time through

https://xjbikes.com/forums/threads/1982-xj750-starter-chain-guide.45503/

There is also caution about the second gear shift fork and being a bit tricky to get in place. I am not sure if that can be an issue or if you paid particular attention to that. The above thread mentions it but states the cases will not go together if not positioned correctly.

 

aye. split the cases, new chain (and oil feed quill as these are trashed with the worn chain bouncing up and down) and guide, I believe the design of the guide was modified because of this fault. The gear forks were tricky to assemble, but all the gears selected when the engine was back in the bike. I am starting to wonder if a stray bolt was picked up by an evil magpie and dropped into the cases while I wasn`t looking.

 

Engine now on the bench again! When I split the cases the lower casing gear shaft would not rotate. I couldn`t get the selector fork shaft out, as the fork that sits in 5th gear was jammed, I had to tap the adjacent bearing out from the inside with a thin drift to get the selector fork shaft and gear shaft out. The gears all look ok, which was a relief considering the horrible crunch when I engaged second gear. ps - I guess I should take this opportunity to service the starter clutch, is it ok to take the rod caps off, to lift up the crank, rather than remove head and barrels?

 

Yes why not? just be careful, remove one at a time and push down out of the way, so that they aren't getting in the way when you replace the crank - you'll need 3 hands....

 

I'm not sure what type of bolt they use but I would fit new rod bolts if you do

 

Damage report---shift fork #1 scored, selector drum groove deformed (this is what put the groove in the bearing housing getting it out)
the parts are all available (used), but I would like to know what caused the jam up in the first place.
Is there a suggested method of positioning the shift fork #2 so it locates in its correct position as you lower the cases back together?
I am determined to sort this problem once and for all soon, to take my mind off the `dry January` torture I put myself through every year!