Valve's and cam's

My klx450r has about 1500km of off road on it now and the inlet valves are screwed.

The bike became very hard to start recently so i checked clearances and the inlets had none. So i re-shimmed 0.17mm smaller and finally they were back in spec. Now 3 rides later 0 clearance again.

So i have pulled my head off ready for new valves. Should i go stainless? Are they the same as the KX?

Has anyone tried different cams? I don't want to go too wild just a little more excitement.

Sorry to hear about your troubles. Always thought the KLX was bullet proof. The KX and KLX share the same sized intake valves (36mm titanium) but the exhaust differ. The KX has 31mm (titanium) and the KLX has 30mm (steel).

Someone else has asked about the differance elsewhere on this forum and have had more indepth answers about the top end differance between the two

As for the valves on the move, have you checked your airbox for dust making it past the filter ?.


I'm assuming dirt past filter is your problem(I believe it to be mine). I have nearly 4000miles on my KLX, and up until a month ago, my valves stayed put...all four hadn't moved in 2yrs of riding. Always starts. I went riding in a dust bowl for a week. Just last night I checked and found some evidence of dust getting past the filter. I checked the valves and the right-side intake has closed to .004. :p

How did the dust get past the filter? Please elaborate so others can check their bikes.

How did the dust get past the filter? Please elaborate so others can check their bikes.

Can't be absolutely sure. I ran two filters that week. I had a well oiled No Toil for most of the week, and changed to the OEM on race day. I used Maxima fft on both of my filters. I was in a hurry, so I didn't look into the airbox throat when I changed them. The race was 4hrs of dusty hell, and both times I pulled them out they were heavily soiled. A lot of the dust in the area is volcanic ash from Mt St Helens in the 80's. Fine stuff that gets everywhere.

I used the stock filter for one year of riding. I held it up to the sun one day while it was drying and i could see straight through it. The holes are just too big.

I'm just not sure on what brand and type of valve to use.

will be having a good look at my filters out in the sun after reading this

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