GP200 unable to engage fourth gear

[Wombat67]

I recently had my engine out so saw it as a good opportunity to replace my clutch plates and chain guide. Apart from checking and re-torquing the nuts on the end plate I didn't touch anything else. Put everything back together (as per the manual), took the bike for a run and found I was unable to engage fourth gear (gears 1-3 no problem and no strange noises from the engine/gearbox). My immediate thought was something cable related but having removed the cables and trying to operate the gears by the tie rod the problem persists. It literally feels like I only have three gears. Before I crack the engine open again I wondered if anyone had any thoughts on what the problem might be/what I've missed.
Thanks

[dickie]

Have you got the one piece gp selector arm? I'm just wondering if the arm is out of position so that it fouls outside the casing rather than something inside. I've certainly done this before, but as I've only ever had LIs, they are 2 piece and can be moved around by one spline.

Also, it's not clear to me if you've rebuilt the gearbox etc or just taken a look inside.

[Wombat67]

Dickie, cheers - it is the one piece rod ( bog standard GP200) I had the chaincase side off just to change the clutch and chain guide, didnt touch the gearbox, just tightened the endplate as a couple of the nuts were loose. I dont think the rod is catching as Ive disconnected all the cables and tried to engage the gears manually. I'll take another look with the wheel/hub off.

[Knowledge]

Did you trap the loose end of the gear cable when you fitted and tightened the rear shock?

It is easy to do and more common than you would think. I trapped the clutch cable in the rear shock the other day and the clutch lever would not move at all.

[Wombat67]

No, that was my initial thought so I've removed all the cables and it still only clicks up to 3rd.

[hullygully]

have you got the gear cables in the correct way round? (soz for asking this question bud as I've done this in the past)

[dickie]

Also check if the swivel is fouling on its own base or mounting bolt head.

[nickw]

You've probably done this already but have you lifted the rear wheel and checked the wheel turns the gearbox in each gear and as you try to change from 3rd to 4th can you hear anything rubbing.
Going on your description perhaps something has dropped into the gearbox?
Good luck but it is looking as though a strip down will be needed

[Leotech]

Has the trunion that goes through the tie rod and the swivel slipped down? I had one come to me where someone had put it together wrong and the trunion was through the swivel to far and it was catching on the casting where the engine number is and wouldn't go into 4th gear.

[Wombat67]

Has the trunion that goes through the tie rod and the swivel slipped down? I had one come to me where someone had put it together wrong and the trunion was through the swivel to far and it was catching on the casting where the engine number is and wouldn't go into 4th gear.

Thats a good shout, I replaced all the trunions so might have put it back wrong or got an errant trunion (too long/hole in the wrong place). I'll put the old one back in and see what happens. Thanks

[Wombat67]

So after leaving it for a couple of weeks (other commitments and waiting for parts) I had another go at this today. Replaced the gear pivot and gear lever (both were worn and probably originals), inspected the tie rod (which seemed ok) and worked backwards from the gear shaft. With no tie rod and tie rod no cables attached to lever, engaged all 4 gears, though a few false neutrals. Attached cables and at the lever end can still engage all four gears however at headset/handle end can only engage 3 gears (with cables not attached to lever (or tie rod not attached to lever), handle moves freely). At the headset end it feels like there is slack in the inner cables yet they are relatively tight at the lever end, next step appears to be having a look at the cable routing/headset to see if anything is snagging or loose!!

[Storkfoot]

So after leaving it for a couple of weeks (other commitments and waiting for parts) I had another go at this today. Replaced the gear pivot and gear lever (both were worn and probably originals), inspected the tie rod (which seemed ok) and worked backwards from the gear shaft. With no tie rod and tie rod no cables attached to lever, engaged all 4 gears, though a few false neutrals. Attached cables and at the lever end can still engage all four gears however at headset/handle end can only engage 3 gears (with cables not attached to lever (or tie rod not attached to lever), handle moves freely). At the headset end it feels like there is slack in the inner cables yet they are relatively tight at the lever end, next step appears to be having a look at the cable routing/headset to see if anything is snagging or loose!!

Shine a torch at where the cable outer enters the headset clamp. If one of the outers has come out, that may well explain your predicament.

[Wombat67]

Storkfoot - thanks for the tip, yep soon as I looked in the headset saw cable outer was out. Put it back in, checked other things people had suggested and took for a spin. All good so cheers to everyone who's suggested something.

[Storkfoot]

Storkfoot - thanks for the tip, yep soon as I looked in the headset saw cable outer was out. Put it back in, checked other things people had suggested and took for a spin. All good so cheers to everyone who's suggested something.

Good news. Glad you got it sorted. It’s happened to me many times over the years