Hello
I am having trouble with my 13HP Murray riding mower.Model 40541x99C OHV130-206810D. TECUMSEH ENGINE.
First it was backfiring REALLY loud:eek:.. in all gears, all speeds.. I cleaned gas tank, replaced fuel filter, spark plug, cleaned carb, replaced air fiter. The engine:
(1) BACKFIRES
(2) Has loss of power
(3) Surges, then starts to stall
(4) runs rough
(5) BLACK, dry soot was found in old spark plug, and inside muffler..
** I NEED TO know EXACTLY where TDC is in SIMPLE terms.. some say TDC is when you line up coil with the 2 magnets on flywheel.. but if I put a pencil in the empty spark plug hole, MY TDC is like 6 o'clock instead on three o'clock where magnets line up with coil..
I have been on numerous Tecumseh web sites, and no one knows where TDC is!
I adjusted valves to .004 (intake and exhaust); does NOt backfire like before,but stalls out after running a minute or so.. FLYWHEEL KEY BROKE?? BURNT VALVE?? PLEASE HELP!!
THANKS I also smell something burning under valve cover.. :confused:

I recently bought a John Deere riding lawn mower and had been having a lot of backfiring and was using a lot of gas till someone pointed out that I had not been using the choke correctly. My experiences were pretty much the same as yours. The engine make a loud backfire noise and ceased to run. Lots of black smoke and it ran roughly. Turns out that you shouldn't run the choke at full throttle. So now after I start the mower, I remember to lower the choke down. Not sure if this helps with your mower -- Ace

Your carb. Is running too rich.