valve cutting

[Ripped78]

I'm replacing the valves on my 2004 crf450 and I am going with this kit [Only registered and activated users can see links. ] I know i need to take it to the machine shop and they charge me $15.00 a cut but do I have to buy the seat to be put in or do they cut the existing seat. I'm very confused on how this works.

[MXtras]

It depends on the condition of the seat. If the new valve sits too low into the head, the seat should be replaced.

Either way, the existing seat will have to be ground - or at least heavily lapped to mate with the new valves. If the grinder guy has a heavy hand, he could easily take more than needed.

I hope you are going to take this to a bike shop and not an automotive guy - unless he has bike head experience. The automotive guys are used to much bigger stuff and can get carried away. Be warned.

Scott

[Ripped78]

Yeah it is going to the bike guys, but I didn't know if I should go ahead and spend the extra $30 to have the seats on hand.

[MXtras]

I would suggest it. The aftermarket seats are likely better than the OEM seats.

It really depends on a lot of things. It's a hard call to make over the net, but if time is an issue, get the seats and be ready for the 'just in case'. If the head and valves are currently in good shape, you might be able to lightly grind the old seats and you could be fine. Hard to say without actually doing the work and that is when you will find out for sure - during the work.

Scott

[Ripped78]

I think I will just go ahead and have them put in just do everything right.

[MXtras]

I think that's your best bet. Not to say you couldn't get away with not doing so, but this way you'll know what you have and you will know it's a complete repair.


Scott

[cetanepusher]

For $574.00 you should have just bought the complete head, and thrown your old one on E-bay.

[Ripped78]

if I do it myself I can save about $150 and that's a new top end and the more work I do on the bike the more I'm figuring these damn four strokes out.

[cetanepusher]

Yeah but thier head is ported and done correctly with a warranty. Not to say your machinist isn't good, but I am sure these guys know thier stuff. That head, a cam and a big bore and your looking at a few extra ponies right where you need them.