Not reving high.

[Daddy_Blasty]

Got an 04 blaster off craiglist and it seemed to be running great only problem was it was reving to high turns out it was just the throttle cable was tangle the quad ran great for about a week then the piston blew. I bought a "cheap" top end kit from ebay that included a new jug and filter we put threw the engine together and it would bot rev out into the highs it would just bog and gurggle. what im trying to figure out is why, it was running fine before then all of a sudden the top end, jug, and filter was replaced and it wont rev out. I then went to the air mixture screw backed it out a couple turns and it wouldnt make a difference just repeat the same thing. Is it an air leak, it it the rings, the coil, the filter, or something else is going on help thank you

 

[DUALSTROKE]

These cheap a** junk china cylinder kits are killing us. There lies your problem. A new piston and bore/hone would have been a much much better solution than these junk kits. Very hard to diagnose a problem when sub par parts are installed. Was the crank good or did you just swap cylinders, bolt it together and shoot for the hills? Piston installed correctly and facing the wrong direction? Did you use that oh so sweet green paper base gasket? As the old OZ would say, did you leak down test it?

 

[dirtysquared]

2nd the above statement. The cheap ebay kits aren't even at a crapshoot level. Boring and honing a OEM cylinder, matching it to a correct sized piston and using Proven Gaskets (OEM or Cometic) is the only way I'd reccomend to rebuild a topend.