….were in the same boat…had monroe motorsport do a top end  on yamaha…clip broke and it was hurt ..lol .finished 2nd. at michigan international…pipe class….all we do is run road race…grtattan, mid-ohio…etc.etc.

Alan,

I know it’s a long way from Michigan, but shipping is less than driving these days.

Send your engines to Jesus @ P1 racing engines. You will not be disappointed.

P1 racing engines
10572 Acacia C6
Rancho Cucamonga‎ CA‎ 91730
(909) 948-2717

There are many builders in the country, but his performance, quality, honesty and prices can’t be beat.

Stu

If you’re going to box and ship your engines, the whole country is available to you. Contact LAD Specialties for a builder in the Midwest. You might have to wait until after Daytona for a response.

L.A.D. Specialties Inc.
9010 South Beloit, Unit F
Bridgeview, IL 60455
708-430-1588.
http://www.ladspec.com/

You should be able to do a quality upper end yourself is not that hard the keys are having a nice round cylinder getting the right piston fit, I kind of like a little tighter with slow break in as it seems to last longer than a lose fit . Now the other thing is if it has been blueprinted the piston has been cut you can stand the new piston next to old and see the height difference you need to cut the skirt to match as that controls your intake spec. I use a lathe but anyway you can keep it even is fine. Be careful with the c lips have had some that break the one with the tab seems to be worse. When putting back together the split on the ring goes to the intake. There is a pin there to hold it. Reuse the base gaskets as the thickness controls the exhaust port height. Do not over tighten as they bend easily and will distort the bore.  Would give you something to do on these cold nights. lol If your near chicago could give you a hand. We don`t run kt100 anymore but has some great memories. Take care

The ideal way would be to measure bore then measure the old piston see what the clearance is for those. If you run road racing clearance could be somewhere around .003 have run well at .004 but with the larger clearance tends to wear by the exhaust ports but is ok if you keep an eye on it. On sprint only engine I will start just over .002 and break in for a long time. Some people like running the hard gold ring and they do last problem being they tend to wear the block. so thats your choice. If you take the piston out and it still has cross hatch and is round just some clean up with some fine sand paper and your good to go.  If you have to hone it that should be done by a pro with a torque plate and special stones. While it is apart you will want to clean carbon from ports but dont use anything that would damage the aluminum as this could be a tech violation. As far as the engine that failed this is an ideal time to learn. Take the upper end apart look that over then see if the rod is blue at the big end the rod is junk if it is. if not locked may have a main bearing failure. To rebuild is easy. Until you get some hands on would leave that to the pros You can just send the crank out.Dont be surprised if the pto half is worn. to take apart you will need a rotor puller and allen wrenches after the rotor is off pull the allens and split the cases face the halfs face down in the oven or hot plate and after heated the bearings fall out make sure its clean and and drop in new bearings do not hit them. There should be some endplay on the crank ideal is about .010. There is no timing to adjust just use a biz card to set the magnet on the ignition. Seals should be able to be pushed in by your fingers keep them straight. Where the pro`s have it is when they take a new engine they square everything up but if yours has been done it should be ok. Hope this helps Have fun.