KX80 to 100.. I think im pissed

AdrianL

Member
Nov 1, 2005
4
0
Hey guys. Hope somebody can help me out with some info here. I am pretty new to Kawasaki and dirt bikes in general I guess. First let me say I have searched and couldnt find exactly the info I am looking for. So it starts with a KX80 I have had for quite awhile 1993 I was told was what year it was. I bought it with the top end toast. Looks like one of the c-clips for the wrist pin came out and just ruined everything. So I got on the phone with the local Kawi dealer and had looked into big bore kits on the net ooOOo. The fellow I talked with on the phone told me the kx80 and 100 used the same bottom end and that I could use the cylinder+head from a Kx100 on my 80. So I ordered up all the parts gaskets and everything.
So today I got to work tearing apart the old an rebuilding with new. It was going pretty well got everything together and noticed the difference in the exhaust ports.. CRAP! So I done some searchign and reading. It is this powervalve. My 80 cylinder had none of this powervalve stuff. And the 80 pipe is just a tad too big to fit in the new port. I've got everything together except for this exhaust so I figure try to fire it up. After I get gas through the system she fire right up LOUD! Obviously with no exhaust OK... So thats my story I guess im just hoping somebody here can enlighten me a bit more about this reguards to the exhaust/powervalve crap. I am a little but choked after some reading I found out that some of the power vfalve setups are run off a geared shaft driven by the crankshaft. I was looking forward to not having to tear into the bottom end of this thing. So what are my options. WHat exactly is going on here. I can't be the only one that has done this before. Thanks for any help and sorry for rambling on!
 

MXP1MP

Member
Nov 14, 2000
1,845
0
You should have given back those parts!!! they ordered you too new of year parts you wanted parts no newer than a '97 -'99 whenever the damn bike got the power valve. It's true that the earlier non power valved years should bolt right on. You should have looked up the parts on kawaski's website and found out what the actual part numbers where.
 

gwcrim

~SPONSOR~
Oct 3, 2002
1,881
0
Sounds like you have a later model 100 top end. You can't retrofit the powervalve assy as there would be none of the drive mechanism. MXPimp is right. Ya shouldn't have fired it up. Now you have used parts and there is likely no returning them.
 

AdrianL

Member
Nov 1, 2005
4
0
Yea. This is what I figured. Im just going to block off the power valve covers for now. Thanks for the responses. Any bright ideas? I managed to get the pipe to fit nice and snug.
 

AdrianL

Member
Nov 1, 2005
4
0
So if I just made a block off plate for the power valve my low end power is gunna suck?
 

motometal

LIFETIME SPONSOR
Sep 3, 2001
2,680
3
you'll want to find a way to wire/rig it so that the valve is open all the time, that is the flapper valve is "up" when looking at it through the exhaust port. The powervalve system on these is a poor design anyway in my opinion, I think you will like how it runs once you get the powervalve to stay open. The exhaust pipe that belongs with that cylinder probably has different specs, if you find a newer pipe (stock) it might give you a bit more power but not sure if it will bolt right up on the frame. Tempting to stick with the one you have unless you run across a newer one cheap. Silicone is your friend.
 

bikepilot

Member
Nov 12, 2004
804
0
I'm pretty sure the newer pipe will fit on your frame. I belive 01 was the first year of the power valve 100, but not sure. eithe way, I do know that the 01 used an exhaust pipe with a smaller header (where it goes into the cylinder) than the 02+ models. The result is an 02+ exhaust pipe will not fit in an 01 cylinder. you can put an 01 pipe in a newer cylinder, but its a tad loose.

good luck
 
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