Bandit 12 head skim

[Sam-Jaffa]

Evening chaps, I've acquired a cylinder head of a really nice Yorkshireman that I would like to give it a fresh start to (the head not the Yorkshireman) how much can be skimmed off safely without worrying about clearances?

[clivegto]

I did read some where about some America lads just dumping the base gasket to raise the comp.

[Sam-Jaffa]

1 hour ago, clivegto said:

I did read some where about some America lads just dumping the base gasket to raise the comp.

Cheers Clive but it needs a skim as it has some small marks and imhonma start fresh with it, new seals and all 

[clivegto]

1 hour ago, Sam-Jaffa said:

Cheers Clive but it needs a skim as it has some small marks and imhonma start fresh with it, new seals and all 

Sam I am thinking it should be safe to skim the thickness of the base gasket of the head. Do a dry build is all ways best though.

[wraith]

I've heard someone on here that had had his head skimmed (bike that is ) by 0.50mm, which thinking about it is about the size of a base gasket.

 (can't remember who, but it was to do with a post about b12/DOT heads) 

[canamant]

I took 50 thou (1.25mm) off an 1100F head with B12 pistons to fit following careful measurement on a dirty build.  You really need to build it up with the old gaskets, time it properly and then do a valve to piston measurementon the inlet at 2 degree intervals from TDC forwards and from about 20 degree BTDC on the exhaust.  The valve to piston clearance will get smaller then bigger as you go.  Then you decide what clearances you can live with and skim accordingly, how close you want to go depends on the use of the engine and the type of rider who will be using it.

If it is just to remove a few marks then there should be enough leeway to get them out.  Or skim the thicknes of the base gasket and fit a 2nd base gasket for peace of mind if you don't want to do the measuring ?