My mower isn't running right. I doesn't have much power. It back fires & it uses a lot of gas. It sound loud like something is wrong with the muffer but I checked it and it seem to be ok. I have a Troy Bilt Pony 689 riding lawn mower. Thanks

Did you clean the fuel jet in the carb? If not that could be the trouble.
Pull the spark plug and put a spoon full of clean gas in the plug hole and put your plug back in and hook up the plug wire and try to start. If it fires up and stalls right after then you know you have a fuel problem. Is your primer bulb working? Sometimes I prime my one engine twenty times before it will run. Worth a try. Make sure you are using fresh gas as well.

If you restart it immediately after it stalls will it run for a lot less time then if you leave it for a few minutes?
I'm thinking the needle valve or seat are screwed up by this Ethanol gas and the flow of gas to fill up the Fuel bowl is slower than it should be. I just went through this.

got oil in it, or do you add oil. Left outside alot, fuel line clogged. Is the gas old. Check the blades and the exit portion of the clippings. Does it have a drive train for ease of moving. those can bog down a mower. good luck

check the compression if ok is the gas getting threw the carb spray carb cleaner in the carb with the air filter off and crank it over and see if it fires if so the problem is in the carb

to be honest the enigne ahas a control that the left side must fire and run before the right starts to fire it sounds to me like you have a fuel issue possibly the carb. is gummed up and dirty.

Have you checked the spark plug? Mine was doing the same thing. Not staying cranked and sputtering while running. I changed the plug and it runs like new. Hope this helps

if what you are saying is true that it starts and runs till you let off the key, then your ign switch is at fault. check this with a test light or d.v.m. to see if your coil + has 12 volts to it with the key in the RUN position. sometimes I have seen power while cranking then when you release key the power goes out..or eng stops cause switch doesn't have power to coil in RUN position, keep in mind there are lots of different Ign switches out there, make sure you replaced it with the right kind, use your test light to diagnoise

Did you check the filter? If the engine doesn't get air they it could cause it to die out like that. Also make sure that there isn't anything in the air line to the carb.

Did you check the gas line and make sure that you are getting enough fuel?

carburetor

sounds like a spark problem ,coils once the carbs load up it takes off and the extra fuel in the cylinder is not fireing so you get a back fire check the plug gaps and make sure it;s the right plug , then check to see what kind of spark you have if it's weak replace the coils