Is it even possible to change? For a couple days it ran fine, then it won't start. It fires, it has gas, it just doesn't seem to fire at the right time. I hate carbs, so I've been having my brother (who is a carb fanatic and a mechanic) dicking with it but this is kinda where we've been reaching a dead end. The timing tensioner seems to be fine as well, might just replace it for the hell of it. You can sit there and feed it starter spray and it'll fire (a nice flame backfire too) but it'll never get to the point of starting. Any ideas?