Hey I need help. I just replaced Intake valves on My sons 04 crf 250r.I got them from rockeymountainatvmc.They are the prox stainless steel valves and spring kit.I replaced because I was constantly haveing starting issues.After inspecting old ones the old left valve was cupped. So my question now is should I have to go back in and reshim.Since changing he has riden about 25 hrs,and bike is back to having a hard time starting. Thanks for any help

You had the valve seats re-cut or replaced too didn't you?  If not, that could very well be your problem.  At a minimum, they should have been re-cut.  Even better, replace the OEM seats with copper beryllium.

New valves means re-cutting the seats, springs to match, and while you are in there, change the timing chain and adjuster. 

If you are on your 2nd piston, you should consider changing the valve guides too.


All this work requires profeesional tools and experience.


I'd send it out.

Yes you need to check the valve clearance.

You should never replace the valves without having the seats cut by a reputable machine shop that uses a Serdi or comparable machine and checks to make sure concentricity is within spec. Not doing so is going to be a complete waste of money spent on new valves. I also agree that you should replace the valve springs the same time. They are cheap. With a fast pro racing one of these they should be able to get close to 50 hours on the valves. If its a beginner junior that doesnt bounce of the rev limiter they should be able to get even more hours on it. 25 hours is a very short life for a new set of valves and you are risking breaking a valve as concentricity is probably not within spec. does valve jobs on a serdi for $79 plus parts, and we have stainless valve kits for $210. Yes that all 4 valves,springs, retainers, and bases. 

Just FYI.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Kevin from Wiseco
      Jeremy Martin Leads the Charge for Wiseco Riders at Daytona Supercross
      Christian Craig Turns in Career Best in 450 Competition
      MENTOR, Ohio (March 13, 2018) – Jeremy Martin showed the way for Wiseco-sponsored riders in Saturday night’s Monster Energy Daytona Supercross presented by Honda. In a season marred by bad luck and misfortune, Martin put together a near flawless ride to earn his first Eastern Regional 250SX Class podium finish of the season.
      Martin qualified eighth for the division’s annual visit to the World Center of Racing, finished fourth in his heat race, and came home second in the 250SX main event, missing his first win of the year by less than a second.

      “It’s Daytona, a real man’s track.” said Martin who sits fourth in points. “It was the toughest race of the year as far as fitness. I had to slow down a little bit, halfway through the main. I was getting close to (race winner) Jordon (Smith) and I was starting to think about where I could make a move on him, then I made some mistakes and he got away from me. Couldn’t quite get close again, but it’s good. We’re on the podium and in contention for wins again. That’s something I haven’t been able to say in supercross in a while. We want to get wins and now we know it’s coming.”
      Martin’s podium was a bright spot, but the rest of the event was rough for the GEICO Honda/Factory Connection squad. RJ Hampshire crashed hard in his heat race and had to be transported to a local hospital. He injured his back and ribs, but shoulder pain left him with the most concern.
      “I felt good on the bike all day,” said Hampshire via his Instagram account. “Had some pretty good speed and my foot just slid off hitting my shifter in those rollers during that heat race. After seeing the pictures from the crash I’m very thankful I didn’t take a shot to my head. I have some fractures in my T3/T4 in my back and ribs. Also have some damage to my lungs which is why I’ll be spending a couple nights in the hospital. I’ll be getting some more checkups this week on the shoulder also.”
      Cameron McAdoo, the third member of the team, was unable to compete at Daytona after being sidelined with a hand injury two races ago in Atlanta.
      Across the paddock, in the premier 450SX Class, Christian Craig got the call to fill in for Team Honda HRC. With the team’s regular riders Ken Roczen and Cole Seely out with injuries, it was up to Craig to carry the load for the factory team, and the upstart rider didn’t disappoint.
      The San Diego native was solid in both qualifying sessions, won his heat race and snagged the holeshot in the division’s main event. After relinquishing the lead to eventual winner Justin Brayton, Craig continued to show he was up for the challenge. The 26-year-old rider raced for second and third for most of the 20-minute-plus-one-lap feature before losing one more spot in the late goings to bring his No. 32 Honda CRF450R home fourth in the final rundown.

      “I had a great week testing with the team,” commented Craig. “They came down to Florida right after Atlanta and I feel like we really improved. Just getting more time on the bike and getting more comfortable was huge. I started off race day feeling really good. My qualifying position didn’t really show it, but overall I was happy with my riding. It’s all about having fun out there, and man, that’s what I did tonight. I was up front in the heat race, fell to third, but then the two guys in front took each other out so I ended up winning. You can call it luck or whatever, but I just put myself in a good position to capitalize on people’s mistakes."
      “I had a good gate pick and some confidence going into the main. I grabbed the holeshot and led for almost the first lap, but [Justin] Brayton got by me pretty quick. I stayed second for quite a while. I just rode my hardest and did my best. Unfortunately, a couple guys got by me so I ended up fourth. The track was so tough. This is only my second time racing Daytona and last year didn’t go well, so I really wanted to get some revenge this year. It’s better than the week before, but man, I was so close to a podium. I just need to keep putting myself in good positions and work on getting better each weekend.”
      Monster Energy AMA Supercross rolls on this weekend when the series visits the “Gateway to the West” for its annual race at the Dome at America’s Center in St. Louis. The 11th of 17 races on the 2018 supercross calendar will be televised live on FS1 Saturday, March 17, beginning at 8 p.m. Eastern Daylight Time, 5 p.m. Pacific.

    • By ThomasM.
      selling Hot Cams Valve Shim Kit that i bought for my 2005 crf250x, will also fit crf250r.
      used 1x 1.30 and 2x 1.55 shims. the rest is still there.
      $60usd shipped in the usa or canada
      please contact me for pictures or if you are not sure if it will fit your bike
    • By DirtRider250x
      Hi all,
      My main question is how can I make my 250r more reliable. I have owned it for 2 years and it was spent about 1 year in the shed probably needing new valves and piston rings (i have been putting it off) Will steel valves last longer and work well in the engine? Also, what are your thoughts of me selling it and buying something newer? is it worth it?

    • By Throttlejockey
      Please post pics only. All other posts will be deleted so it doesn't get out of hand. PM the poster for more info or create a post.
      Violators will get a one day ban from the forum.
    • By bull413
      I checked the valve clearance on my 06 crf250r and both exhaust valves is at .007 and the intake is (left side) .005 and (right side) .000??? idk my feeler gague only went down to .002 and it would not slide in.
      Is that ok for the exhaust? Do I need to just shim the right side on the intake? or does both need shimming?