[Leardriver]

Here is my dilemma.

I want to put a new piston in my '08 450X after 200+ hours, just for the sake of maintenance and boredom.
I switched to Kibblewhite SS valves when the bike was a week old. I bought it in 2010 as a leftover. I had the valve seats cut, and the clearance hasn't changed in 9 years. SS valves do exactly as promised.

I can't handle the idea of opening up the motor and changing a piston, without also replacing the valves. Since I don't need stronger springs, I can replace all four valves for less than $100.

I don't live anywhere near someone who can cut the seats, and I don't want to mail it off somewhere, and not get it back in time with a Moab trip coming up in three weeks.

Since the valve seats have held their ground, how many of the seven deadly sins will I be violating if I lap the new valves into the used, but in nice condition, seats. The valves are not coated. I know, the correct textbook answer is always to cut the seats, but most people are changing Titanium valves over to stainless valves. My valve clearances haven't even changed .001 in 9 years, so my seats are not a mess.

Just trying to have someone forgive me of my sinful thinking.

[JimDirt]

I am sure Ken could tell you for sure , but I would think that a "slight" lap (use a Sharpie to see the pattern) would tell you if the seats need to be fit/cut to the new valve face or not , more than a minimal hand lap (not sure what seats are in it) I would think would necessitate a recut if the pattern shows minimal seat area contact ... In other words , I think if you do a minimal hand lap using a Sharpie so you can see what is exactly touching and where , it will tell you weather the seats are fine and slap it together , or that the seats need to be cut to the valve face (as angles can slightly differ) , basically , you want to make sure you are getting a full face of the valve coverage with the seat , if the surfaces mate up , then I think you are good to go , if not , then you must have someone (Ken ?) recut them ....

[Aussiecrf230]

I would actually be concerned that lapping paste may become embedded in the seat and continue to lap when it is back together. I always cut or ground depending on material and checked fit with Prussian blue.

[Leardriver]

I am already planning to do any lapping as an experimental procedure, and let the coverage pattern tell me what the next step is. I have a shop about an hour away that will cut the seats while I wait, so maybe I will shake the dust off the Gold Wing and have an excuse to go for a ride.

I just get in a groove when I am disassembling, and want to put it back together right away, but after the years of flawless service, I suppose I should honor the cylinder head with the reward that it deserves.