First kx500 rebuild advice appreciated

[Pmcg]

I've been lurking on here since I got a chance to ride a friends 01 kx500.  I was really happy with my 95 kx250 until that moment.  Since then I have been looking for a 500 motor.  I found a 94 motor for $300.00 locally on craigslist and snatched it up.  I have read the rebuild instructional on this its and its great. Once I tore into the motor it became apparent that the KIPS valve and the piston got way to close


Is this a common problem?  Obviously I will take out the KIPS valves and inspect/replace. 

As a result of the KIPS issue my head has a small ding

Any advice.  Doesn't look like a big deal to me.

I will be getting the cylinder bored and would like to put in a window piston.  Any recommendations on a good shop for the bore?  I see Pinsonnault racing is a forum sponsor so would like to use them but their website seems to be down.  Are they still taking new jobs?  Any advice on where to get the window piston?  I would also like to get the crank balanced any advice on a good shop?

Thanks in advance for the help. 

[Motorrad]

Pinsonault is the BOMB!  PM him   Greenkaw24   if he doesnt chime in


doesnt look like Kips hit.. looks like Meltdown on the edge for a long time..       (signs of detonation,   bad piston wash (lean)... etc)

[Pmcg]

Thanks Motorrad.  Your motor work on the air filter change thread is inspiring.  Can you give me some more info on how you lapped the head/cases? 

I'm going to send the cylinder and crank to Pinsonnault.  Seemed really knowledgable and was nice enough to answer all my stupid questions. 

[Pmcg]

Cylinder and head have been sent off to Todd at Pinsonault Racing.  He will be boring the sleeve, porting and polishing the cylinder, fixing the squish on the head, and cutting the window into the piston.  I plan on sending the crank down for balancing as well.

After splitting the cases I noticed that the clutch pushrod had become mangled.  I am not sure if I need a new case of not but would appreciate any advice.

Here's the case where the clutch push rod rides


And here's the pushrod mangled into the gear shaft.  I was able to bang it out and obviously plan on replacing


Any ideas on why it happened and if I should replace the case or not I appreciate it

[nirvanafan98]

That carbon buildup looks my top of piston.

[USMC 500]

Thanks Motorrad.  Your motor work on the air filter change thread is inspiring.  Can you give me some more info on how you lapped the head/cases? 

I'm going to send the cylinder and crank to Pinsonnault.  Seemed really knowledgable and was nice enough to answer all my stupid questions. 

My "Motorrad" prepped KX500 is as powerful if not more powerful than some of the 90's Team Green built 500's that I've ridden.  Lots of grunt but healthy and easy to use.  Very 4-strokeish down low and very "Charles Mansonish" on top.....hahahahaha