I have a Troy-Bilt TB230 push mower. I left gas in it throughout the winter and went to crank it and it would not turn over. I've put in new gas, replaced the fuel line, changed the oil and air filter and it still will not start. I have also cleaned out the carburetor. I do not know much about engines and took a lot of it apart at the beginning, but I believe everything is where it should be, minus one piece (looks like a type of guard). I know I did something right because now it at least backfires and tries to turn over where as before it wouldn't even do a thing. Any suggestions of what else could be keeping this from not turning over? These are some of the specifications of the mower from Lowe's website. Engine Brand Briggs & Stratton Engine Torque (Ft/Lbs) 7.25 Engine Displacement (Cu. Centimeters) 190.0 Cut Width (Inches) 21.0 Transmission Type Self-propelled Start Type Pull start Drive Type Front wheel drive Speed Control Variable Series Name TB230

I have a briggs and Stratton 20 hp engine 31P977-0575-E1 OHV on a craftaman rider. Just bought from somebody claimed only 40 hours or so on engine and has sat for few years. First time mowing with it there was some white smoke coming from exhaust not too bad figured it would clear up with more driving. This time finished lawn seemed to be smoking more just about got it put away and it began sounding like it was backfiring loudly would not restart let it sit for a while and tried again did not want to turn over much seemed like too much compression. Pulled plug cranked for 10 seconds or so and put it back tried again still same problem cranked then stopped like it was getting full of compression. pulled bolt on flywheel to check flywheel key it is fine. pulled head looks like new head gasket cant see any problems with it. Piston and cylinder full of oil and carbon build up intake rod is bent. Should I replace intake rod and try again or does engine need more work. How is the oil in the cylinder and what steps should I take from here? Thanks for any help.