Using a SkyHawk 66cc Angle Fire at over 8000 Feet

For one you have a Skyhawk motor, you don't get a better motor anywhere no matter where you buy it. For two your elevation is going to make any motorized bike motor you get sing like a sick horse. Don't change the Gas to Fuel Ratio, keep it at 16-1 (8 oz of oil to 1 gallon of fuel) for now and after your break in switch to the 25-1 or 32-1 and with your elevation a 20-25 to 1 used at all times is better. The HP/Racing carb that you have is also a very nice Carb...But again if you are not interested in going over 40 MPH (which you really don't want to go this fast on a bike anyway) It don't matter if you use the HP or the regular NT, only difference is at top end. You don't want a cooler spark plug, you want a hotter one and yes the resister type is best (NGK BR6HS is perfect). I thought I also read that you were using 90 Octane fuel? No my friend use 92 octane and use good fuel (don't mess with the ARCO junk, I use Shell) Every 66cc 2 stroke should use 92 octane. I find that Kings motor bikes is the best vender (my personal opinion) its where I got my 7 motors from and there warranty is also 6 months and the costumer service is great. (very good vender/company) Now, the movement of the piston within the cylinder wall is unfortunate but instead of just tossing it and buying a new motor, first check your rings#1. if the movement is a back and forth movement of the piston it could be the rings, if its a side to side twisting your bearing is shot. and the person that told you its almost impossible to fix is incorrect its as easy as just changing the bearing (piston bearing) now if it went bad because of the sleeve (the rod) thats a indication for a new motor. (better to get a new motor then try to fix this problem, that would be a little difficult for the average person). Not to boast my position or anything like that but I do own 7 of these motorbikes and have been fixing and repairing 66cc 2 strokes for years. All the advise you have been given is very informative but you must (a big must) consider your elevation (it sounds like thats where most of your problem is coming from) High elevation make these machines run really weird. Believe me ,been there,done that to many.

ok ,I am pretty sure with the length of this thread that there must still be oxygen that high up

I have even seen the spark problem on a thread on here was caused by the magnito screws being loose,so first off do you have a good plug spark

Its best to use synthetic oil, Your problem is not that of your oil. What kind of gas are you using?

Use 92 only. and check your float.

And use very good gas , not the ARCO junk. I use Shell 92 octane with ethanol.

If you use a 16 to 1 gas to oil and ride your bike on a strong downslope, use a new plug (a hot plug not colder one like it was suggested to you by someone else) use 92 octane with ethanol and bring your bike down to an elevation level of 2000 or less (just tell you get it running) and if possible ride it back up to your 8000 feet level with the motor this should work
(((REMEMBER))) Elevation means everything with these 2 strokes.

It will not start huh?
If you are suspecting your clutch I gotta ask: is the engine turning over or is the clutch just slipping when you try to start the engine?
Let's start with the basics.....

Take out your spark plug and look inside the hole while pushing the bike a bit in gear and see if you see the piston move as your pushing.

Yes, make sure that the pads can free float in their pockets. As they are from the factory they typically need a little trimming with a razor blade to float properly. Do not cut too much off, just enough so they will not get hung up.
Also, if there is any grease or oil on the pads, inner plate or outer plate, clean it off with brake cleaner or similar solvent. Do be cautious to avoid washing out the grease that lubricates the teeny ball bearings in the clutch hub though. If you do happen to wash the grease out, those teeny bearings need to be routinely lubed anyways.

If I were you I'd let it run in abit before you get to worried, mine honestly ran like a dog at run in but after about 600km's she really found herself.

Dont forget to match up the ports on the intake and exhaust with a dremel or round file after the carbon has had a chance to give you a mark, it makes it easy to do the gaskets while ur at it. It'll take about 2hrs and a six pack on a free day if ur fussy.. that alone will make abit of a difference. The bug keeps biting though

With ur speedo ya win some ya loose some IMO now, dont bother spending too much time trying to make it work if u put that in coin for what u could make an hr u would have bought 3 other types already some will just work and others just won't not worth the head ache.. Personally I found a wired speedo branded SIGMA to do the trick...

Have you tried running the motor on the stock 44tooth setup??

oops disregard apart of my msg just read the whole thread.
If it doesnt pop at all when ur forcing it to start and ur sure ur carb is sweet u have found ur problem.
To check the fuel is coming through if u pull the plug out and turn the motor over by hand at the wheel with the fuel on you should see vapour coming out the spark plug hole.
I always remind myself to go back to basics comp., fuel and spark. Good luck bud

oh yeah with the sbp kit its abit of a biacth to start until u get the knack of it might b easier if u revert back to the standard setup for a tad till u get it sorted helps rule out any crap and makes it easier to fault find