Putting in New Intake valves on my 2001 yz250f

I am getting ready to replace all 5 valve seals and valve springs, along with the 3 intake valves. I've never messed with the valves before except to shim them, will this be a very difficult task and does anyone have any helpful tips or comments that may help me along the way? Any help would be greatly appreciated.



You will be removing the cylinder head. It's a fairly involved procedure that will result in there being a large number of small important pieces that all need to go back exactly where they came from. Do not attempt it if you have no shop manual, or don't feel you have a decent amount of mechanical experience or good sense.

> Read, understand, and follow the procedure as laid out in the manual as exactly as possible. Understand is the key word. Do not stumble ahead blindly just because you are told to.

> Lay out your work area so that it will not be disturbed at mid point by people shuffling through your disassembled engine.

> Use a divided parts tray, several small containers, or some other way to keep things from getting lost.

> Take pictures with a digital camera for reference later.

Oh, and the head bolts have washers on them that like to turn up missing just after you realize they are there so that you can search the entire area to be sure they didn't drop in the crankcase. Don't ask me why I brought that up.

The front chain guide will be a bit of a nuisance. Be certain it is in its proper place BEFORE you bolt the head down. You will be about 80% finished by the time you find out the hard way.

The actual removal and replacement of the valves should be handled by a good machine shop. Find out who your Yamaha dealer uses to send their heads to.

And replace your cam chain.

Two of the head bolts are slightly longer than the other two. Might want to label them. A,B.C.D. OR 1,2,3,4 to reoriantate them.

You should also have your valve guides checked/replaced. If you don't you are wasting your time!!!!


I have decided that trying to change the valves myself will be a bit too much work for me, I am from Indiana, does anyone have any suggestions as to where I should take the bike to have this done?



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