Flippin' primary tensioner

[Tee]

Just went to change the OE primary chain tensioner for an automatic one I bought a while back and found that the bolt holding it all in place is jammed solid, and the head is messed up as well so I can't really do anything with it. I have tried an impact driver on it but it won't shift.

Any ideas?

Does anyone know the right size allen key to use as well (Just out of curiosity).

Here's a link to a photo of the mashed up part:

http://i97.photobucket.com/albums/l2...20709_1843.jpg

I didn't notice it when I did the 15K service so it must have been done before and that was at 10K (Dealer serviced)
Still, it's not as bad as my brother in laws broken compensator sprocket nut
Sorry Swede.

[Steppenwulf]

Nut splitter?

[panheadpete]

Tee, I've just had a look in my 2000 RK's case and mine is a cross head screw..no help there, then.
All I can suggest is that you measure the key that 'fitted' but wouldn't shift it - most impact drivers use metric bits. You then need a slightly larger key, by which I mean that the key you tried may have a slightly larger imperial version, if that won't fit, try tapping it in with a small hammer, that may also loosen the screw's grip: impact drivers devote a lot of their force to turning, you need direct, inward, force to seat the key and loosen the screw. Having trouble explaining this sensibly...I've always thought that countersunk Allen bolts are rubbish; not enough depth if any degree of tightness is needed.
Good luck,
Pete

[Tee]

Thanks for the advice guys but I can't work out what size of key should have been used initially as it's pretty mashed up, and that would give me a starting point. I have tried metric and imperial but neither appears to fit because of the mess that's been made of the countersunk socket. They could so easily have used a bolt in that position as well, and it would be much easier to remove if things went wrong.
I don't even know where I can get imperial bits for an impact driver so I might have to cut down an allen key

[Scotty]

Take the top off it with a drill and pull the tensioner bracket of, with a bit of luck you will have enough of it left to get a grip of it with mole grips, heat the casing up around the bolt and it should spin out.....Or cut a slot in the top of whats left of the screw and use a screw driver in conjunction with the mole grips with heat!

[banquo]

Not sure if it's the same as this, and I can't look at your photos at work, but I'm pretty sure mine was a Torx T40 (might be obvious from the photos, but i can't see them either..)

An old T40 bit could perhaps be held in there with a wee blob of weld, and the heat should help free it off...?

[Mr B]

Looking at that picture, you won't get anywhere using an impact driver now, it's too badly damaged. You will need some oxy acetylene with a small jet to concentrate the heat. Heat the head up, taking care not to burn anything else. Using a centre punch with a longish point, knock it undone while it's still hot.

The heat will travel down the length of the screw and melt any loctite that is holding it. Also countersink heads are notorious for being a bastard to undo, because they stick on the taper..heat will expand this and give a small degree of clearance.

Good luck, it's a 2 minute job with the right tools.

Brian.

[Tee]

Thanks guys - very helpfull. I will have to try some other method though as I don't have access to Oxy and don't know anyone who has.

[spinlondon]

Get a chisel, make a slot in the fastner and using a flat bit on the impact driver, remove the fastner.
You can obtain bits for impact drivers from SnapOn.

[Phil]

Tee, have you had the bike since new?

That is not a stock fitment.Stock is a Philips head style tapered screw.

You have had a service done at a Dealer, but I don`t know why the would have messed with that fastener.