Can you remove the head......

I need to replace my cylinder head.......can it be removed with the motor in the

frame? And how much time does flat rate give you.. :applause: BC

Oh yeah, 03 YZ450

it will be 6 trillion dollars.if it were a 2 stroke $50 tops. :applause:

can't you just lap the journals again.i'll let you borrow MY socket this time!!!!!

I can remove the head of my 426 with the engine in the frame. It's no more difficult than taking the valve cover off for the valve adjustment.....well, maybe just a little.

Seriously, the hardest part is messing with the carb getting it off and on.

can't you just lap the journals again.i'll let you borrow MY socket this time!!!!!

Im thinking its hurt a bit more than the socket hone can help :applause:

I went out to Sand Hill Friday night and it lost compression on about the twenty

third lap.... :ride: No clank clank just kicks through easy and won't start..

Pretty sure the head is fried.....$$$$$$$$$ It lasted longer than I thought it would...

Something that will make it simpler is to get the chain tensioner and whip guides out of the way. If you really want to avoid pulling the flywheel and stator, you can only do the front whip guide, but that's the one that will give you the most grief if it stays in place anyway.

Lift the head up a little and slip a piece of 1x2 or a screwdriver handle under it to hold it off the deck. Pull the guide straight up out of its socket, rotate it 90 degrees, and pull it out the top. Now the head will come free of the engine more readily.

Bear in mind that without both the front and rear guides in place it's possible to loop and extra link of timing chain off the bottom of the crank sprocket. The absolute best way to avoid that is to pull the stator so you can see behind it. Then you can change the timing chain, too.

ive got a bunch of new oem head parts for your bike if you need them.

sorry to hear of the sucks when it starts to look expensive.if you need any machining let me know.


No clank clank clank, but lost compression?? Maybe the gears spun on the cams enough to throw the timing off. I would definitely check the timing before you tear it apart so that you know what you are working with before you strip it down.

If you remove the water spigot on the front of the head, it comes off pretty easy even with the tensioners in place. Tdub

Thanks Tryce, long time no hear from everything OK? drop me a line once in awhile....Well your socket hone worked for quit comes the $$$ part.

your friend BC

BC did you check with EDCO?? Their fix is pretty inexpensive. Tdub

Edco fixed my can journals for $100 on my yz400. WEll worth the $. Bike is still running strong.

edco has saved many heads for me.

Thanks Tryce, long time no hear from everything OK? drop me a line once in awhile....Well your socket hone worked for quit comes the $$$ part.

your friend BC

i'm in the same boat. i just had to order a new cylinder too. might as well do the piston and rings,new timing chain,tensioner,while your at it.$800 later..ouch! just ordered all my stuff today. it hurts to think about it but, i need to ride!!!

Im planning on pulling it apart this weekend......I have been so tired everyday after work

I just can't think of anything but dinner, hot shower, and hit the sack......

This weekend for sure........

starting the project

step 2

other side

step 3

clean up

thats it........

intake cam bearing damage

Look familar Tryce..... :applause:

Im calling Mike Crowther Monday and taking the head over to see him.....

Its not as bad as I thought....But I guess the valves were sticking open because the lifter buckets are binding from the cam bearing being smeared over the edge of the buckets bores and are so tight I can't spin them in their bores.....Mike will have to hone the bores I guess?

I'll let you know what happens, BC

Just a little tip...before final assembly, make sure the cams spin FREELY when the caps are tightened down...if not, just polish the cam. Then I lube the cams(journal surfaces and lobes) with moly when I final assemble.

PS...just drop the cam chain down, then pick it up after the head is installed...alot less hassle than fighting with the wired chain. Tdub

thats not bad at all.should be a easy fix for them.

I have been running the engine with a flywheel weight over the mag flywheel(Stealth13 oz) I talked with Tom White when I first bought the YZ which was 03 and he wasn't running any weight at that time. Riding mostly Vet MX. Said he liked the way it hit with

a stock flywheel......I cowtrailed ( or attempted to) my bike and felt the weighted flywheel helped me in slow sections. Im more into MX now (having raced all year) and

was wondering if I should leave the weight off? What do you use on your racers...


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