Author Topic: KX450 valve clearance  (Read 6807 times)

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Offline ThrottleJunky

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KX450 valve clearance
« on: January 23, 2011, 11:48:49 AM »
Help!
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #1 on: January 23, 2011, 12:09:53 PM »
Trying to piece this 08 450 motor together.  Had to change out the cases.  Acquired a set that were marked 08 but realized they were 07 cases because the oil pump wouldn't fit. Then my new 08 cylinder didn't fit, so I had to get an 07 cylinder.

Overcame those obstacles and can finally see the end of thIs project.

Installed my cams, timed them, checked cam clearance. Now ready to check valve clearance.

Major Problem: 1/4" clearance between tappets and cam. (Yes, my shims are in..)

Compared part numbers on 08 and 07 top end parts. Same cams, same tappets, valves, chain.  The head is the only different part number. 

With all of these top end components the same, how can the heads of the 07 and 08 be so different to give me 1/4" gap?     
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #2 on: January 24, 2011, 04:24:47 AM »
It's hard for me to believe the valve location has moved up 1/4" by reshaping the combustion chamber. Kinda radical change in one year...
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Offline don46

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Re: KX450 valve clearance
« Reply #3 on: January 24, 2011, 05:17:39 AM »
Are you sure you have the right CAMs? I was under the impression that the 06-08 heads would interchange, I have used valves that I had bought for an 07 on a 06, used a 07 crank in an 06. As I see it there can only be 2 problems 1. wrong valves, stems to short  2. wrong cam profile, as an after thought do you have the buckets over the shims (yeah I know stupid question but I had to ask any way)
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #4 on: January 28, 2011, 10:06:33 AM »
Don
i acquired a head, cylinder and a set of cases that needed repair, all marked 08.   I ordered all my 08 parts, fixed the cases and started building.   My new oil pump wouln't fit, it was too thick.  Checked part numbers and noticed the 07 number was different. That pump fit my cases fine. At that point, I realized my cases were 07's. 

The next problem was the 08 cylinder that slid right down onto the piston and case dowels. The casted lug on the timing chain side was about 1/4 inch off front to back on the 07 cases.   

Ordered a 07 cylinder from US Chrome, got that on, slid my 08 head that was equipped with new valves, springs, slid my 08 cam in and set the timing. 

Now the 1/4" gap valve clearance issue!  SHIMS ARE IN!!   Checked the head part numbers and Oh No, the 07 head part number is different!

So I know it was a lil late but I checked all the head component part mumbers. Same valves, springs, tappets, cams. The only part different was the head.

Got a Kawi tech guy that suppose to get back with me soon!
'There's more living in five minutes flat-out on a bike than some men have in an entire life'.

Offline 1989kawasaki

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Re: KX450 valve clearance
« Reply #5 on: January 28, 2011, 10:13:18 AM »
looks like you spent ALOT OF MONEY :cry: :cry: :cry: :cry:
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #6 on: January 28, 2011, 10:18:37 AM »
Yeah, I bought this bike to do  a 500AF conversion and decided to check out the new four stroke power that I've been avoiding. 

This is what I started with...
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Offline don46

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Re: KX450 valve clearance
« Reply #7 on: January 28, 2011, 10:42:47 AM »
I have another head, not sure what year it is, I bought it for a spare, was told it was an 08. I know the valves are the same and looking at a cross reference chart for hot cams they are the same 06-08, so there should be no clearance issues by mix and matching components. and according to wiesco the gasket kits are the same from 06-11 so I would assume the head and cylinder would be interchangeable. you didn't get KLX components by chance, even those I would assume would be the same. something is truly funny here. I don't have an 08 anymore, only an 06, 07 and a 11 but I'll look them over to see if there is a visible difference.
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #8 on: January 28, 2011, 11:49:49 AM »
Maybe I'm missing some parts.  Stacked up the valve, springs, keepers, shim, then the tappet.  Am I overlooking something? 

At this point, I'm not sure what I have.   
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Offline don46

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Re: KX450 valve clearance
« Reply #9 on: January 28, 2011, 12:20:54 PM »
something is odd, maybe the wrong valves. attached is a picture of the valve train does yours look like this?
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #10 on: January 29, 2011, 01:32:27 AM »
I think that's what I have.
The valve/seat contact area on my head was too big on the diameter.  I didn't have all of the special tools to resize the seat angles so I used one of my resources for help.  He sent the head back complete with new valves, guides, and springs. He even installed a new exhaust gasket.  This is his specialty but I think it's time to check out what valves are actually in there...
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #11 on: January 30, 2011, 06:09:17 AM »
More information:

Dug my 08 head out of my buddy's aluminum recycle bin.  Slid an old 08 valve all the way in the guide. Depth mic'd  from the face on the top side of the head to the valve stem.

Did the same with the set up I was trying to assemble (don't know what head I actually have -think it's an 07).

Approx. .200" difference between the two.  That's the gap I had between the tapppet and cam! 

(remember 07 and 08 have the same cams, valves, springs - only difference is the head)

That's hard evidence the combustion chambers were extremely reconfigured between 07 and 08!

Still waiting for the word from my head connection to see exactly what he gave me... 
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Offline 1989kawasaki

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Re: KX450 valve clearance
« Reply #12 on: January 30, 2011, 06:11:33 AM »
4 strokes sound like they are a PAIN IN THE .......
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Offline don46

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Re: KX450 valve clearance
« Reply #13 on: January 31, 2011, 05:56:08 AM »
More information:

Dug my 08 head out of my buddy's aluminum recycle bin.  Slid an old 08 valve all the way in the guide. Depth mic'd  from the face on the top side of the head to the valve stem.

Did the same with the set up I was trying to assemble (don't know what head I actually have -think it's an 07).

Approx. .200" difference between the two.  That's the gap I had between the tapppet and cam! 

(remember 07 and 08 have the same cams, valves, springs - only difference is the head)

That's hard evidence the combustion chambers were extremely reconfigured between 07 and 08!

Still waiting for the word from my head connection to see exactly what he gave me... 

I don't think the combustion chamber being different is your issue, valve train is the same, so if you compared your 08 valve to whatever it is that you have and your off by .200, well theres your problem. it sounds like your builder used to short a valve.

The 06 and 07 were the nastiest KX450f's they mellowed them 08 and newer, I have valves that I can mic for length, you can pull your valves and measure them as well, that will tell you whether or not you have the right valves.
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Offline ThrottleJunky

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Re: KX450 valve clearance
« Reply #14 on: February 02, 2011, 11:01:10 PM »
Problem Solved!!!!!!!!!!!

I aquired a brand new, out of the box,  08 head. Took an old valve and slid it in place and mic'd from the top head face to the stem tip.   Same measurement as my grenaded head. GREAT!!!!!!!!!

Don, your right, my builder put something on me that I can't identify. I thought I was going NUTS!  I do appreciate your  helping me work through this issue.   

Doug, thanks for the help also. 

Time to get busy and finish this project!

George
'There's more living in five minutes flat-out on a bike than some men have in an entire life'.