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Advice/help on valves

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I am looking for any and all advice on my current valve situation. I have had my 250X for about 5 months and have had zero problems until...I checked my valves yesterday. This is the 3rd time I have checked them. The first time after breakin (2 weeks) every thing was spot on .011 on the exhaust and a tight .005 on both intakes. I check again about 6 weeks ago and again .011 on exhaust and .004 on both intakes (starting to go south!?), still with spec. After a hare scramble and a couple more rides I checked again this week, exhaust .011, left intake a tight .004, right intake ZERO!! :cry:

Finally my question to those of you that have been unfortunate to have your valves at zero, I have a hare scramble tomorrow and really would like like to race do you think I am safe to shim the right intake and go for it or am I risking a major head repair. I would like to be able to limp along with the current valves until the KW valves are out at which time I will swap everything.

I have seen that those who just shim and they appear to be back into the head again within a few hours of ride time adjusting the valves which I am o.k. with as long as I am not risking big damage. The shim job looks pretty straight forward with the exception of the cam chain removal/tension release. It appears there is a special tool for this? If anyone has experience or pointers on this it would be greatly appreciated. I would also be curious what your original shim size was on you right intake? I am hoping my local shop will let me buy several different size shims and bring back the ones I don't need, but I need a starting point or range. I'm hoping their tolerance are such that I can at least get a ballpark starting point!?

Sorry about the novel I just wanted to give some background on my problem.

Thanks in advance for any help or suggestions!! TC

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Finally my question to those of you that have been unfortunate to have your valves at zero, I have a hare scramble tomorrow and really would like like to race do you think I am safe to shim the right intake and go for it or am I risking a major head repair. I would like to be able to limp along with the current valves until the KW valves are out at which time I will swap everything.

I was in the exact same dilema as you. I reshimmed and I have 1HS and 1MX race on since plus some trail riding, a total of about 6 hours. After every ride jsut keep checking. Mine still havent shifted yet, it staying right at the .004 that I shimmed it out to.

As far as the cam chain tensioner, f you dont have the tool do what i do.... just completely pull it out, just removed the (2) 8mm bolts and the thign slides right out... problem solved!

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... do you think I am safe to shim the right intake and go for it or am I risking a major head repair. I would like to be able to limp along with the current valves until the KW valves are out at which time I will swap everything.

That's what I'm doing. Plan to check them again after my next ride to see how quickly they are 'going south'.

The shim job looks pretty straight forward with the exception of the cam chain removal/tension release. It appears there is a special tool for this? If anyone has experience or pointers on this it would be greatly appreciated.

I made the cam chain tension release tool with a thin piece of metal and a hack saw. I made two, actually. The first one was spot on, but it was too difficult to grab the darn thing. I made a second one with a larger end that I could easily twist around. Made the task MUCH easier.

I would also be curious what your original shim size was on you right intake? I am hoping my local shop will let me buy several different size shims and bring back the ones I don't need, but I need a starting point or range. I'm hoping their tolerance are such that I can at least get a ballpark starting point!?

Every bike is unique, so you'll need to 'do the math' when figuring out the new shim size. I had to purchase three new shims, but luckily my math was accurate and all valves are now spot-on. Heckler put an Excel spreadsheet together for those who hate doing their math homework. :cry:

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Thanks for the quick response guys!! On short notice I will pull the cam chain tensioner and check the shims. Are the shims labeled or do I need an acurate micrometer? I'll do the math and hopefully get a ballpark figure on the shims I need, then hope like he!! our local shop has them in stock!!

If anyone else has any suggestions or pointers it would be gladly accepted!! If I have time I will try to take some pix of the process and post them later. Wish me luck and I'll post later my results (of the fix and maybe the race :cry:)

With any luck I'll see you at Metcalf tomorrow Jimmy, except I'll be racing with the old guys in the morning.

Thanks again, TC

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Mine were labeled still, some people where off. Good luck with your race, I will probably be getting their around 11 so swing by and say hi, 94' grey toyota pick-up, X with R plates #676.

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On short notice I will pull the cam chain tensioner and check the shims.

If you take out the tensioner to adjust them be sure you release the tension before you put it back in. You can do that with a flatblade screwdriver.

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I wanted to say thanks :cry: to Novaman, Throttlejockey and Coldcase for your advice!! I would not have tried this without some guidance from you guys. It actually was a fairly easy process.

I ended up swapping my original shims which were 195 on both right and left to 192 left and 182 right. My valve clearances are a perfect .005" left and a tight .005" right!! Fortunately I was right on the first try using the calculations in the service manual.

The bike starts easily and ran perfect during my race. For how long only time will tell!? The course was pretty tight for this race so not a lot of high speed throttle pinned type riding, but when I needed it the bike responded perfectly.

I plan to check the valves again this weekend to see if the clearances have changed...hoping NOT!! I have a number of pictures I took during the re-shimming process if anyone is interested? I just need to figure out how to post them. Thanks again, TC

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:cry:

Ran mine this last weekend after the reshimming. The power difference was very much noticeable. I think my power has been robbed over time, and to get it back is super.

Congrats on your bike operation. :cry:

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I also noticed a big difference in power after re-shimming. I guess you don't notice the gradual falloff of power caused by the valves, but I sure noticed the power gain after, especially when pulling long steep hills!! Thanks again, TC

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