Cutting valve seats

[klp]

Does anyone have the technology and know how to cut new valve seats? I have an older xr100 head in need of some attention.

[butcher bergs]

As in lapping the valves?

If so, it's as simple as suction cup the size of your valves and some valve lapping compound.

If you're talking about a multi-angle job, I got nothing.

[klp]

Yeah thanks, I don't need a multi angle job, just 45 degrees as near as I can tell.

I have lapped them already and the exhaust still leaks a bit. The valves show wear on the faces and the seats must as well but you cannot really see it. I was going to get new valves as I want to get everything spot on as the motor is getting a BBR 120 kit. I think the faces should be done at the same time, yes?

[butcher bergs]

Hard to say without seeing it and I doubt pics would tell the entire story.

If you get new valves and lap them to the old seats you should be fine unless there is severe damage to the seats. FWIW; I bent a few valves on my CBR motor and alls I did was purchase new valves and lap them to the existing valve seats. Haven't had any issues regardless of that engine living at 14,000 rpm. Something to think about.

[Kurlon]

The XR head, even new benefits from a good 3 angle valve job, dunno who to suggest in Mass though.

[Stromper]

Some where I have new way cutters but you'ld need the proper
valve guide rods

See if you KNOW what angle is on the valve face.

PM me if you want to play

[tls25rs]

dunno who to suggest in Mass though.

You could try Harry's Machine, I think they are in Northborough ( sp?) right on RT 9 behind the Amazing store. Good work and good prices.

[Speed Demon 828]

we can do that job for you.

[Kitt]

we can do that job for you.

and way less headache than trying it yourself.

[KB]

I have a guy in Manchester NH that does great work! PM me for details.

KB

[BluGixxer]

My 2¢
If you start cuting valve seats, make sure you know what your doing, if you cut to deep trying to get a three angle seat, you need to pay attention to the depth of the valve at the other end. And also after you lap them in, (messes up the geometry somehow) if your a first timer, and your doing other mods to gain HP, bite the bullet and let an experienced machinist do it. It will be worth it
3 angle valve job is probably the biggest bang for the buck, very few people relize how much can be gained by just putting those angles back to spec.