04 CRF250x Int valves tight, Shim or not

[smallcarshop]

I`ve been having starting problems and running problems. I found the intake valves very tight (.001 clearance). I replaced piston and installed a R cam 20 hours ago. (I know I should have done a valve job then). My question is do you think it`s safe to adjust valves for one more ride this weekend. Valve job is very expensive let alone breaking something. Also is there a great shop for head work.

Thanks Darrel

[MajHazrd]

Tough call, that's a personal call.

I shimmed mine down where I was using a 150 shim. From the look of the valves when I took it apart I wouldn't go any farther. The stock shims are usually around 180 - 190.

Your experience may vary.

Can you tell I have cabin fever sitting here going through TT threads waiting for my cam and the snow to melt.

[highmarker]

If they've never been shimmed before I'd shim for a little more clearance and take that weekend ride. If you don't know if they've been shimmed before it's your call? Mine started new at 5 and went down to 4l and 3r and took a set and haven't moved for a long time.

[condor74]

If you have a ride to go on then go ahead and shim them. They may last 15 hours or may last 3 hours...start saving for new valves and springs.

[99klr250]

Shim them and go ride. Yours has worn about .004". But, going forward keep a close eye on them. From what people say, once they start to move, they keep moving (wearing). Also, plan on having the valves replaced before they move much more. And if you want longer valve life, consider replacing with stainless steel.

I've shimmed mine a couple, adjusting them a total of .009" adjustment. After that much adjustment the valve was starting to cup where it seats on the head, so I shipped it off the get stainless valve installed.

[jsdak]

I`ve been having starting problems and running problems. I found the intake valves very tight (.001 clearance). I replaced piston and installed a R cam 20 hours ago. (I know I should have done a valve job then). My question is do you think it`s safe to adjust valves for one more ride this weekend. Valve job is very expensive let alone breaking something. Also is there a great shop for head work.

Thanks Darrel

You'll probably last the weekend, but who knows after that. I just recently had my right intake zeroed out, shimmed it, and it only lasted a couple rides after that. Went pretty quick.

I had the valves done (stainless), and I can't wait to enjoy the benefits of valve longevity now.

I had mine done by AS Racing (asracinginc dot com), and was completely happy with the service. I highly recommend them!

[yz450fguy]

get those crappy stock intake valves out. My brothers CRF didn't last at all until we put stainless steel faction MX valves in. It has gone over a year without having to shim.

[moto_x2005]

how many hrs did you go previous to the R cam? if you have quite a few hours (being an 04) and you throw a more aggressive cam in it your going to look a smaller valve life.. you could have very well sucked dirt somewhere in the intake track or failed to clean an airfilter..