Hi.

I've been trying to get the boyfriend's XTRS working and I'm running in to a weird issue. Basically it wasn't starting which I narrowed down to a compression issue; I replaced the piston rings and the compression tests fine.

Now it kinda starts but dies after a few seconds or if I touch the throttle. I believe the problem is with the carb since there's a good spark and compression is fine. While experimenting I found that for whatever reason, turning the idle mixture screw all the way in and applying maximum throttle allows the bike to idle perfectly fine and, with a little throttle, it will rev up but too much throttle will kill it.

It feels like a fueling issue but what exactly is a mystery; as far as I can tell there are no intake leaks, the carb is new and the problem persists with the old carb too, I've tried cleaning and replacing the spark plug but it makes no difference.

So if anyone could throw me some ideas on what to try to fix the problem that would be great because I am really confused at the moment xD