750 Inner valve springs


New member
Nora Sweden
On my 750SF cylinder head the new inner valve springs are interfering with the outer valve springs. When I turn the camshaft the valves hangs up for a moment and then comes banging down into the seats!
I have a set of old inner springs but does anybody know where I can find new wich have the right outer diameter? (Wolfgang only have a few that he needs for himself).
The cylinder head has new guides, the valve gear is all new parts, the inner and outer valve springs are new from the same dealer and the only reason I can think of is that the springs are momentarily binding.
I don’t know if you assembled the head but if guides were tight enough to hold open valve they would be a hammer fit.
Grinding paste residue could do it but unlikely to be repeatable, I would look closely at rocker spindle binding or something just Fouling the head casting and causing the valve to stick. Is it both valves/ one valve/both sides? Is the Tappet foot going past the valve head and catching on the collet?
Sorry guys, I WAS WRONG!
I have made an adjustable camwheel and I had not tightened it enough to the camshaft before I made the first turns.
The bangs came when the camwheel let go after the camtop passed maximum lift....😳
From now I will try to not draw fast conclusions.