TRX 3.3 bad performance all the sudden
 

Hello, just drove my T-maxx for a couple of min's and I think there's a leak somewhere there seemed to be exhaust coming out somewhere else from the exhaust pipe, seemed to be facing the front of the engine. I think there's a hole in the plastic exhaust but it kind of went away after a bit, I did not notice any fuel leaking out the heat sink so I'll have to check again. Another thing I noticed was it was emitting a barely noticeable high-pitched whirring sound when at idle, and when accelerating it seems slower and when I go to stop the engine does not go down to idle smoothly, it kind of slows down in bursts seeming like it goes up RPM then drops down a lot and continues doing that for about 2-3 seconds until it gets to idle. I'm guessing its a bad bearing but I have to tear the engine down to tell, I'll do that later today, I'm planning on getting some Boca bearing if that is true, if so should I get front and rear or just rear?

Change both bearings while you are at it.

Replace both bearings. If the rear bearing is really worn, check the crankcase between the front and rear bearings for score marks. The crank will wobble in the case and wear the case and in some cases ruin the crankshaft to crankcase fit enough to cause major tuning problems that cannot be tuned out.

If the engine ran good with the current carb settings before and isn't now, don't mess with the carb. Disassemble the engine, replace the bearings, reassemble, and test run. Have a new glow plug on hand too. I just did bearings in a pair of 3.3s - one of which is at 8.5 gallons and the other 5 gallons. They run like new now.

Ok, finally got around to tearing it apart, I don't see anything wrong with the bearings, they are smooth and don't have any corrosion, maybe its my spur mesh being to tight, I thought I set it pretty good though, oh well.

One thing I did notice is my piston sleeve is really rough near the bottom and was very difficult to remove, I had to heat the case up and very carefully using grippers remove it, I did score the surface around the top a tiny bit and around the outside but I can't see that effecting anything.
https://imgur.com/a/xDlgu