One thing I wanted to point out here is that there isn't such an animal as an 80cc in one of these china girl engines, they are either 66cc or 48cc.
Many of the problems people have with these kits are self inflicted but there are lemons as well because any of these kits can be a crap shoot like has been said many times, I suggestpulling the head off, the intake off and removing the cylinder/jug before ever even running the engine, replace the upper bearing/wrist pin bearing with a quality one, make new better intake gasket or purchsase upgraded ones from a vendor, replace the mounting hardware with higher quality bolts or allen head cap screws, make sure gaskets match the ports, remove any burrs in the intake or exhaust ports with dremel, and use a good fuel resistant sealer like Seal All or Permatex High Tack Sealer on jug to case and intake gasket, these engine aren't hard to put on many bikes but time should be taken to make sure everything is right or you will have solid heck from the get go.
Just make sure things are right and ask lots of questions on here if you're not sure.
If you do choose to replace the upper cage bearing here is the part # KBK 10X14X13, you can get these from www.motionindustries.com
or if you have a motion industries industrial supply local just go by and tell them what you need, they may have to get it out of a warehouse like mine did but I had them in just 4-5 days best I remember, these bearings are one of the weaker points in these little engines, I have one with about 1500 miles on it now with it's original bearing and I've had engines go 200 miles and that bearing let go and trash the entire upper end of the engine, NOT a must replace item but one that many of us on here would point someone to do since they are known to fail probably more than any other critical internal part.
There are many things that can be done to these engines and components but what I have listed above is what I think is a good idea from the start based on my own experiences with the ones I have.
Originally Posted by Len455
Well thanks for all of your help guys. I just ordered the pk-80 from pirate cycles. Cant wait.