So I got a GT80 from GB. It came with a flex exhaust. The poo poo pipe is way to restrictive. I took my Dremel tool to the exhaust to open that up a lot more than it was stock. I plan on getting a different pipe for this bike soon. But I am using the flex exhaust for now. The next thing I proceeded to do was take this engine apart and correct all the Chinese crappie worksmenship. I'm going to include pictures of most of the things I did to the motor. Yes I did find metal shavings inside of this motor. Yes they're porting was crappy. As with any of these two-stroke kits you have to take them apart to make sure they're put back together how you want them. I ended up correcting the top sides of the transfer ports. As well as opened up the transfer ports on the crankcase. I also put a proper hole in the intake side of the piston to help the Reed valve work better. They put a boost port on the cylinder from the factory. You know the Reed valve the Boost port the three piece clamp sprocket and the exhaust Plus the cylinder head we're all reasons I bought this motor. I'm going to try to include as many pictures as I can of what I did. This way anybody else can see what you gotta do to get these motors up to Snuff. I probably put a good 10 hours of porting into this motor I finally got it together and have only wrote about two miles and so far the CNS Carburetor is giving me fits. But then again I haven't had a chance to take it for a proper Drive. I'm running opti2 at roughly 70:1 for break in.