Trying to remove the reed valve block really stuck on.

[oldguyRD1964]

Hello,

I have an RD250 and I had to swap cylinders as one was chewed up and I had purchased a spare for situations like this. I wanted to put my original reed valve block on but it seems to be really stuck on the cylinder. I'm assuming some gasket sealer was added at some point by the previous owner. I used a punch and small screw driver but I cannot get it off. How hard would you go with a hammer and screw driver. I did tap about 20-30 times around the block. Appreciate your reply in advance....

[Jspooner]

I take a flat punch about 3/8" in diameter and give that a couple of good whacks with a hammer on one of the sides of the block and that usually does it with minimal to no damage. Just make sure you stay away from the sealing surface for the reed block on the cylinder.

[oldguyRD1964]

Thanks very much will give it a try also thought about putting some denatured alcohol on it as well will test it out tomorrow.
Thanks '64

[m in sc]

throw a bit of heat on it as well. not a huge amount, but some. try to use  a soft drift or punch if you can.

[RDFL]

Wood dowels make good drift for such things.

[oldguyRD1964]

Thanks for all the replies, I got it off by using a wood chisel, with not a lot of hammer... Lucky there, but noticed one thing, the old cylinder reed valve (not sure what it would be called) cutout with female screw holes is not square I tried putting the replacement reed block in and it's definitely off by 1/8"...

I found out the mechanic who did the original seal repair on my bike 5 years ago put longer screws on the reeds and he tightened them at least 20lb maybe more I needed a hammer to get the screws out (allen). 

All good but very strange...

[Dvsrd]

20 footpounds would most likely break an M6 screw. Normal torque for M6 is 10Nm or 6-7 footpounds