FZRSupport: the FZROnline Archive

After an unsuccessful carb. sync. on my '90 FZR engine, I realized that my intake valves are indeed ready to be replaced, (as I was told when I had new seals installed) so I ordered eight new ones. I then called the machinist to have new valve seats cut on the head. After explaining to him why I wanted it done, he admitted he didn't have the tools to do a head this small and recommended lapping the new valves first. He said these problems are usually remedied with new valves AND lapping only.

I understand that valve lapping used to be a very common do-it-yourself procedure; often (best) done without any power-tools. Does anyone have any experience in this? I'd love to learn and don't mind practicing on my own bike. I think I heard you can do it by hand with lapping compound, a small wooden rod and some hot glue.

Valve lapping is a messy, PITA job. I've heard of placing clear tubing over the end of the valve stem and the other end attached to a drill.

Any idea what they were going to charge?

Find an automtive machine shop that specialises in foreign heads-they're around.

If they are worth their salt, they will have arbors/pilots/cutters/stones to fit out valve guides and seats.

I wouldn't get that deep into a 16v head and go to it half-assed.

Well, I lucked out in one sense. I After I realized the seats weren't square and couldn't be lapped into shape for a new set of valves, I went to a couple of professionals. The dealer wanted $250 to cut eight seats and reassemble; a machinist shop wanted to use only a stone, then I found Franz Auto machine in Great Falls. Ray used to race FZRs and knows this engine, having done the job many times, ported and polished them, etc. He'll grind the new valves to let me keep my shim sizes and cut fresh seats for $17 per valve. And he wants to save me money by avoiding the things he knows I can do. Man, does it pay to ask around.