First time Valve Adj. on 01' 426, Help? Chain Advice?

4 replies to this topic

Posted February 18, 2002 - 04:07 AM


Hey Guys,
Finally got to get some ridin in this past weekend after the mud dried up! Under decel, bike seems to be popping and backfiring more than normal. I have not yet attempted to adjust my valves but am ready to do so here shortly. Have service manual but just wondering if anyone has any good advice on doing this job. I was told that the valves are shim under bucket style and will probably need to be shimmed if they are out of adjustment. Probably have 30-40 hrs on the bike. Will be performing the BK mod also. Any tips on the valve adj. will be great. How far in or out were your valves when checked. did it help the performance etc. etc. Thanks!
Next stock chain is on last adjustment and wondering what chain you would recommend, oring non oring, what brand? Probably will replace the stock sprocket with a 50t. Just let me know guys. Thanks a bunch, Frank

  • skthom2320

Posted February 18, 2002 - 04:45 AM


Sorry, no valve adjustment tips but the popping on decel may simply be from your fuel screw. Is it colder than when you rode last?

If so, try 1/4 - 1/2 turn OUT from where you are now. Use the next size larger pilot if you need to go more than 2.75 turns out.

As for chain, I've installed the DID x-ring from Rocky Mountain. It was about $70. I haven't adjusted it since I put it on and have put about 20+ hours (8-10 rides) on it!

I also have a 50t rear but will probably go back to the 49t on the next sprocket change. BTW - Rocky Mountain has steel rear sprockets for $14.99. They weigh quite a bit though ...


Steve T

[ February 18, 2002: Message edited by: skthom2320 ]

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed

Posted February 18, 2002 - 06:54 AM


Thanks Steve, It was cooler than the previous times I have rode. In fact it was snowing (flurrying) like crazy. It was messed up 30 mph winds snowing and the sun was shining, still was a good day of riding though!! Appreciate the info on the chain. Why do you want to go back to the 49t? How is the gearing of the 50t? more bottom or mid range? Thanks again, Frank

  • sirthumpalot

Posted February 18, 2002 - 08:05 AM


Mine pops on decel on cooler days (I'm too lazy to play with the fuel screw) but with that many hours on the motor it's probably a good idea to check the valves anyway. It's really easy, just follow the manual as it's very good. I did not have to remove anything but the tank and seat.

As for the chain I just tried a DID x-ring on Saturday for the first time and it worked great! Look for the thread here called "the x-ring experience".

  • skthom2320

Posted February 18, 2002 - 09:25 AM


I would agree that checking the valves is easy to do and that you should do it anyway.

As for the gearing, I personally don't notice that much difference between the 49 and 50. I just liked the 49t a little more for my favorite track. Makes second gear a little more useful there I think. Early on I ran a 13/49 (about a 14-52) thinking I would be a tree-bumpin' trail rider. I didn't like that at the local MX track at all.

I think it really depends on the track you are riding on.

For $14.00 from Rocky Mountain, it won't hurt you to try or keep a couple of different sizes for different terrain/tracks.


Steve T

Related Content


Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

Wilson the Blue Privateer by jetfuel

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.