Problem Need Advice Please
 

So I'm new to the Remote control scene and want to get into it , when I was younger I had small toy rc cars but now I'm interested in bigger faster and more complicated kits.Recently I got a HSP 1/10th scale On Road touring car it was working fine broke it in and tuned it well (As far as I could see) and used it very often for a month.I stopped using it as I hadn't the free time so yesterday I got it out.It wouldn't start at first but I got it going it had dead fuel in it from not burning it off from last time I cleared it out and it started up fine.So after a while of running I encountered a problem my car would not shift gear from 1st to 2nd and I didn't know why so when I stopped it I inspected the underside of the car to find that the one of the two gears showing has worn down and the teeth have lost material I planned on posting a picture but I don't have enough posts. I have no idea of the problem or what I can do about it I need Help ASAP and help or advice is greatly appreciated thanks:)

your engine may be a little rich, lean the top setting just a little at a time and run it to see if will shift or it can be your 2speed setting

If you intented to stop play for a long time, it is better to put few drops of after run in the engine and make sure the cylinder is in the upper side and tighten it. Everytime you start playing again with engine cars which you have put aside for a long time, put some feul direct into the engine like a solvent to clean the engine before starting it, check the cluth bell and start with more richer setup, also check the one-way bearing as this bearing is most easy to get stucked with the shaft, in your case, most likely either the one-way bearing is locked with the shaft or the cluth bell is too loose that when the engine starts, the gear turn and destroyed the plastic gears.

Looks to me that you have to replace the worn gear. Do you have the car manual? Do you think you can replace the gear by yourself?