KLX Valve and Jetting Adjustments


I have a 2000 KLX 300 that hasn't been ridden much yet, but I have read a lot about regular valve adjustments being necessary. What exactly is required to do this, how often should it be done, and where could I find some detailed instructions?

2nd, If running the bike at higher speeds and then letting off the throttle the bike almost always backfires once, so I'm assuming its jetting is set a little off the mark. Where can I find out how to adjust this? The owners manual that came with the KLX doesn't explain anything regarding these two issues.

Thanks in advance...

KLX Spode

For the valve adjusment, unless you are VERY familiar with motorcyle shim and bucket-type adjusters, save the headache and pay a shop! It's well worth the money and save the agravation.
As far as the jetting: is the bike stock? It's really not uncommon for a four-stroke to pop when you decelerate. If it seems to be excessive, check to make sure you don't have any exhaust leaks, especially around the headpipe to cylinder area.

00 KLX 300 (mine)
00 KX 100 (her's)
94 PW 50 (their's


checking valves on a klx is easy, but you really should have the manual (klx250) and the supplement.

i haven't had to adjust the valves yet, but it doesn't look any worse than adjusting on my klr650. the hard part on that bike is just getting the valve cover off.

-sparkymarky, from norcal


My bike is still stock, however it is a Canadian version, which means I don't have the exhaust plug and no snorkel on the airbox. Just the airbox lid with the hole.

Where could I purchase a detailed KLX 300 shop manual?


The intakes are prone to "cup", if you keep the motor stock, you'll have to adjust the valves less frequently. I have a modified 97 KLX 300 and in the first 2 years, my valves did not need any adjusting. I put on about 20 rides @ 50 miles per ride per year.

In year 3, things changed, I had to adjust the valves for the first time by putting in new shims on both intakes. This job is not to hard, just need to use a little common scense and take your time, work the learning curve and it's done.

In year 4, had to do it twice, and would have had to do it a 3rd time, but ran of specs, so I just recently pulled the cylinder head and you can definitely see the intakes worn.

Never had a problem with the exhaust valves, nor have a heard of anyone else having a problem. If you can't get a manual, checking the valves is extremely easy. Remove (Gas, or Petrol tank), then pull the valve cover off (3) bolts, use feeler gauge, record your measurements, put grease on rubber valve cover gasket (inside w/ the nurls) and reinstall.

I suggest going to http://www.buykawasaki.com, you'll find the valve adjustment specs and all the parts schematics, for the KLX 300.

Hope this was of some help !!!

MC Out !!!

WR 250

I had good luck finding a shop manual for my (gasp) Mojave fourwheeler on e-bay. When I first bought the machine I ordered the manual from the dealer and waited for over 3 months. The dealer kept saying they were back ordered from Kawasaki but that didn't do me any good. I cancelled the order after my wife found the manual on e-bay in a short 5 minute seach. Plus the brand new manual cost less than half of the $48.99 the dealer wanted. :)