slow engine

My engine is a GT5 Stinger with a Jakes head and a ported cylinder body. I'm running a yz700 exhaust and a boost bottle. I also have an rt carburetor and an SBP shift kit, with an HD freewheel. My Bike frame is a Felt Vintage Iron Bolt, with a sealed gas tank. Im using the recommended NGK spark...

ok, so, i have built my second engine on a bike, the first one was with a friend on his bike, everything went fine except the carborator filter kept falling off. i built my bike on my own with a little hole drilling help from my girls dad. And my bike is solid no problems at all, everything is...

This is making me scratch my head help :/ How much is the max speed for a 2-stroke 66CC engine because mine will go only 6-7(km/h) or 4.3mph. Should I use the warrenty and tell the seller to get a new one? thanks,