Mk 2 Powervalve removal

[Trevt]

Hi all. Reborn CRM owner here. I've actually owned mine about 12 years but due to life getting in the way its been laid up the last three. I was a member on here but it was so long ago I cant remember my username or password so have kept it simple and re-registered.
Any way I recently decided to do the bike up and its currently stripped down. On pulling the barrel it was in need of a rebore. I saw a barrel on a local site which had been rebored and came with new piston kit, gaskets etc and as mine is damaged around the exhaust mount, decided to buy this other one.
All seemed well except the piston was too tight for my liking so I had a local firm hone couple of thou out.
Since then I've noticed that the piston is rubbing very slightly on the powervalve. I decided to take the valve out to clean it and possibly lightly sand it - cue problems. Looking at the manual it looks like it just pulls out from the left (cover side) after removing the cable pulley etc but mine won't budge. I tried removing the plug on the right which has an allen key type socket to see if that made any difference and it's absolutely solid. I've tried heating it and no joy - If I put any more pressure on it I'm just going to totally round off the key socket.
So I'm wondering do I need to remove the allen key cap on the right side or not before I damage it beyond repair or am I missing something?
Sorry for such a waffling first post but I'm well wound up tonight and considering throwing it all in a box for another three years. Cheers

[Ewan67]

Hi.

One I tried to get out was like this. I ended up fabricating a slide hammer that threaded on to the PV shaft. A few sharp knocks and it was out. The thing that looks like an Allen key cap is just part of the casting I think. It doesn't undo.

Cheers

Ewan

[knackeredMk1]

A few things here.

You need to have the cylinder rebored with the power valve insitu so the PV is cut away for precisely the reason you found. I.E. the piston/rings catch PV with potentially catastrophic results.

The PV shaft should just pull out from the cover side quite easily. Pull out the shaft and then the PV should just pop out of the exhaust port with a little bit of jiggling. Be aware that though the MK2 and Mk3 barrels look and function the same and are interchangeable the PVs are actually different and I'm pretty sure they won't fit across the models. You do not need and should not try to remove the Allen headed plug. It is to seal the machining work done on manufacture.

If the PV shaft won't come out easily give it a tug with a pair of pliers, but don't damage the thread. Or do as suggested above.

[Trevt]

Thanks for speedy replies.
The barrel was rebored before I bought it unfortunately but I'm pretty sure its just catching on carbon build up.
Its not enough to impede the piston but you can feel it touch if you move the piston in the bore. I'm hoping a thorough clean of the valve will be enough - hence wanting to remove it to do it properly.
Will the shaft pull the seal out with it or will the seal stay in situ?

[Trevt]

Slidehammer it was.
The shaft was almost welded to the valve with carbon so took some getting out.
All's well now, valve cleaned and back in with a new seal because I broke the old one.

Big thanks again for pointing me in right direction.