I've recently installed an 80cc raw motor engine on my bike. I've done everything that I can think of. But it seems that the chain is bending rather than flowing around the little cog in the engine. I have plenty to tension or play rather. The bike starts and the engine runs, but when I throttle it up it goes no where. The engine stays running but I can't seem to get the bike to go. HELP PLEASE. The tech at raw motors said to loosen the small sprocket a bit. I was uncertain of overall safety after being told this. if I did that. Please give me some insight.