You could try an engineering supplies shop.
Have you installed new guides?
Have you ever reamed guides before?
You will have to check/recut valve seats if you ream guides to ensure everything mates up properly.
Might be easier to get a shop to do the lot.
C30F Power Up needle
2 turns out
Baffle out, Screens In
It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas