KLX 300 Valve Guide Replacement

Has anyone had to replace a valve guide for the KLX300? Wondering if this is something I can do myself or should I enlist the help of a Machine Shop?

Couple of weekends ago I had an intake valve let loose and it bent. As a result it took out half of the guide that protrudes into intake port. Luckily there was not significant damage to the head that I cannot easily repair. I reviewed the Service Manual and it indicates too heat the area around the guide to +/- 300 degrees then pull the guide. In looking at the valve guide removal tool it appears to be and hand tool leading me to believe the guide does not require to be pressed in our out.

Any opinions or experiences would be greatly appreciated. Trying to get the Bike back on the road on a limited budget and if I can save a 100 bucks or so by using a machine shop will sure help me out a bunch.


I just had my head redone recently although he did not have to replace the guides. All new valves and installation was $200. If you have the ability to get the guides out yourself you should go for it. The worst that can happen is not being able to accomplish the task which means a trip to the machine shop.

That's my thought exactly. I re-read the service manual and I think I'm going to give it a try...Heat up the area around the guide to 300 degrees and hammer it out.

here is another question though. Ive installed steel bearing in the past by put them in the freezer for while before installation and that has worked pretty slick. Should I also do that with the new guide being that it is cast iron or will that make the cast iron brittle when it come in contact with aluminum heated up to 300 degrees?

So I'm guessing that no one has ever replaced a Valve Guide?

if you have the valve guide driver tools to do it, it is 100 percent easy. without it i couldnt do it. i didnt freeze the guides either. i just put the head in the oven and popped the old ones out and the new ones in. its super easy with the tool.

Need to get opinions again!

If I understand correctly I need to have the valve seat cut after I install the new valve guide. I'm reading on here to be careful not to go too far on cutting or risk trashing the head. Would anyone recommend just installing the new guide, lapping the valve in and doing a leak test to see if the valve seats correctly. I figure it's 50/50 either is seats and I'm good too go or it doesn't and I have the dealer cut the seat.

Valve face to seat area must be precise for a good seal. If your guides were worn enough to require replacing, I'd bet that the seats got out of spec also from the valves hitting them off center.

Ride on


guide removal is easy, installing is another story...the new guide can be damaged if (hammered) in incorectly and the valve stem seal will not fit right. also the guide ID has a tendancy to shrink after its installed making the valve too tight in the guide. too tight means a chance of sticking, hitting the piston, bending, breaking off, ect.. finally the valve seats should be cut after the new guide is in and sized, chances are it is going to need more work than lapping, but you never know...

Thanks for the opinions. The guide wasn't worn and is not the reason for the replacement. I bent the valve and it broke off a piece of it on the combustion side of the head. Thanks for the advice...I'll get a shop. To do the work.


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