GN250 chain adjuster bolt not turning problem

[crazyv]

Hi,

I have run into a small problem while trying to adjust the slack on the drive chain on my GN 250.

Basically when I try to tighten/loosen the chain adjuster it does move, but seems to "roll" on and on without ever tightening or loosening (hoping I haven't lost you yet) - Basically the thread on the bolt is mashed up somehow and not behaving.

So I think I need to somehow cut the bolt and replace with a new one. But how? Or is there another method to get it out?

Thanks for any suggestions on this ...

[Vern]

Hi if it is any help I would block up the back of the bike so rear wheel is just off the ground, then remove the rear axle bolt then you can work on the bench with them. I would clamp the adjuster bolt in the vise and cut the bolt off as close to the bracket as possible, then try getting the other piece out with pliers from inside the bracket. but it is possible that the thread could be gone in the bracket. Vern

[Squiggles]

I've got a couple of spare adjuster blocks off a GN, otherwise just cut the old bolt (got a grinder?) and replace with a new one (hoping the thread isnt toast else you'll probably have to use a tap), flick me a pm if you need a hand as its only a two minute job

[crazyv]

Hi if it is any help I would block up the back of the bike so rear wheel is just off the ground, then remove the rear axle bolt then you can work on the bench with them. I would clamp the adjuster bolt in the vise and cut the bolt off as close to the bracket as possible, then try getting the other piece out with pliers from inside the bracket. but it is possible that the thread could be gone in the bracket. Vern

I was thinking of something similar - I guess I need to consider from which side of the adjuster arm I need to cut it out...

I've got a couple of spare adjuster blocks off a GN, otherwise just cut the old bolt (got a grinder?) and replace with a new one (hoping the thread isnt toast else you'll probably have to use a tap), flick me a pm if you need a hand as its only a two minute job

Thanks Squiggles, I do have a grinder - I will give that a go but as above I need to find which part of the bolt to cut.

What do you mean by using a tap? (hammer it out?)

I will give it a go before i PM you.

[hayd3n]

looks as though you are also running out of adjustmet is the chain streched??

[Squiggles]

Thanks Squiggles, I do have a grinder - I will give that a go but as above I need to find which part of the bolt to cut.

What do you mean by using a tap? (hammer it out?)

I will give it a go before i PM you.

Remove the adjuster block by undoing the axle and pulling it through partways, then pull the adjuster off the back, it looks like the thread is toast so just use the grinder to take off the end with the head, as close as poss to where its screwing in, then you should be able to twist it through(or pull it through if the threads that had it) from the other side w pliers.

Dont use the hammer, by using a tap i mean if the thread is missing off the block and you need to redo the thread to fit another bolt...

[hayd3n]

What do you mean by using a tap? (hammer it out?)
.

tap and die
a die to dress the thread and a tap to dress the bracket and nut
also you could recoil the bracket
still appears you have a worn sprocket or streched chain

[Squiggles]

looks as though you are also running out of adjustmet is the chain streched??

Yep he's running out of adjustment...

A quick check question (may be insulting but ya gotta ask ), when you've been adjusting the chain have you been loosening the axle first?

[crazyv]

looks as though you are also running out of adjustmet is the chain streched??

Yes you are correct, certainly running out of adjustment ... I may have to use the last adjuster block hole or better get a new chain. Both sprockets look good though. Previous owner had the chain replaced too and its only done 20000 Km's.

Yep he's running out of adjustment...

A quick check question (may be insulting but ya gotta ask ), when you've been adjusting the chain have you been loosening the axle first?

Not insulting (for me anyway)
Yes, have been loosening the axle first - I did check a YouTube video before digging my hole

[howdamnhard]

Hi,

I have run into a small problem while trying to adjust the slack on the drive chain on my GN 250.

Basically when I try to tighten/loosen the chain adjuster it does move, but seems to "roll" on and on without ever tightening or loosening (hoping I haven't lost you yet) - Basically the thread on the bolt is mashed up somehow and not behaving.

So I think I need to somehow cut the bolt and replace with a new one. But how? Or is there another method to get it out?

Thanks for any suggestions on this ...

From the pic it looks like the thread has stripped.Remove the split pin from the axle nut and then slacken the axle nut off.push the wheel forwards a little in thedirection which slackens the chain.This should create a gap under which you can stick a flat blade screwdriver.Re-tighten the axle nut now and then using the flat blade screwdriver as a lever to gently apply pressure as you unwind(anti-clockwise) the bolt.Hopefully this will cause some undamaged thread to take and allow you to remove the bolt.Then replace bolt and locknut. By the way your chain and possibly sprockets may be due for replacement as it looks like from the pics you are getting close to end of tadjustment.The original Chinese GN chains are lousy,replace with a good Japanese one.