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 very sturdy with a perfect fit. They are both the same engine, a grubee skyhawk GT5 2011, my friends bike is pulling at least 30 mph and faster passing all the trafic (he does have a speedometor), the advertised speed is 30 mph. My bike is only pulling at LEAST 20, working its way up slowly once it reaches 15, any ideas what i did wrong? my own thought would be that i probably over oiled it (which i did at first) but will that effect it that much?