Valve Job

[Tiger Tony]

In the continuing saga of the head gasket replacement, now come the valve job. Removed quit a bit of carbon and found the valves and seats pitted and worn. So I'm regrinding the valves and will then lap them into the seats. Anyone know of the spec for the margins on the valves? They seem a little sharp and I can't find any direction in the manual. More to come.

[iansoady]

There's not a lot of material on the edges of those valves. I'd be worried about them getting so thin they get red-hot and start to cause pre-ignition etc.

They're not like the proper valves fitted to our old bikes.....

[Mustang]

not to mention I would be curious as to what size shims you will end up using .............if you took too much off the valves you will not have any shim size to get proper clearance 2.0 mm is as thin as you can go on the shims

12 new valves may be in your future...............

[Tiger Tony]

I know the valve margin's look thin, but what has me confused is I have only cleaned up the one. The one on the right has not been touched. Does anyone know what the specification is on the margin, I hate to make a decision just on looks.

'03 Lucifer Orange Tiger

[Sin_Tiger]

That looks rather a lot of cut surface, you may find you are right on the limits of shimming as Mustang suggests. Did your machinist recut the seats as well? My personal preference is to cut the seats and then lap the valves to check contact, if you have around 0.3mm unbroken contact I'd leave it like that rather than machine the valves. Small valves like these have very little 'hard' meat on them so it's easy to go through it.

Can't help you with the angles at the moment.

[Tiger Tony]

That sounds like a sensible approach to machine the seats and lap the valves to fit. We have only cut one seat and machined one valve. I'm planning on continuing the work on the valves tomorrow afternoon. In the morning, I'll re-inspect the valves and seats. I'll list my findings tomorrow. Thanks again for your input guys. One question, if I need new valves, is there any source besides the dealer?