the other day running my baja5b i managed to flip it on its roof more than half way down the road with the engine still turned on so it took a while until i got to it , anyway when that happened the engine has run like crap eversince , the plug got flooded with fuel and so i changed that and it went a little better but still not 100%, took it home and started suspecting the ring so i put a brand new ring on the piston and it goes alot better , but when i changed the ring the top of my piston had at least 1.2mm of black gunk carbon build up so i cleaned that off as most i could , but still it doesnt run exactly 100% . am i missing something could fuel have gone inside the air filter and wet the sponge causing it to run like crap , i want to just replace the piston with a brand new clean piston and maybe try how that goes .

Never heard of this to be honest... I wonder if being upside down is definitely related to the problems? My RCs have been upside down plenty, sometimes for a minute or so, without ill effect. <shrug>

I too have had my RC gassers flip and turn turtle still running. No ill effects for me either.

I dont know what to say. Changing your wing and all the build up could be a sign of another problem. Maybe you carb is askew and either too rich? I dont know. Can you post a pic of your piston and cylinder of when you had it open to replace the ring?

Also, give your carb a check, make sure it didnt get knocked loose or bent the bolts such that teh intake manifold block was mashed or warped, and/or the gaskets were springing leaks.

Also, is your pipe still on nice and tight? Again, check the pipe where it bolts on. And look at the pipe itself. If it got a significant dent in it, that could ruin your return pulses to the exhaust port.

Also, check the stinger, makre sure it is not pinched closed or clogged up. If it is only clogged up, that fortunately is a very simple fix.

yup a fuel filled air filter will make it run crap ... id give it a squeeze [ if its a foam filter] and see what come out .