***"I see a couple embers (for a lack of a better word) coming from the muffler"*** I don't think you can use a better word to describe the...uh..embers. That is exactly what they are. These embers indicate a fairly heavy build up of "oily soot" (carbon) in the muffler and exhaust passages from the "oil burning" you stated. Worse (maybe) is the probability of the combustion chamber (piston crown, cylinder head, and the "uncovered" upper margin of the cylinder) being covered with this junk too. If this a very old engine ('71 model, still under warranty, right?), the intake manifold passages and intake valve probably have their fair share of buildup too. Interesting point you made about the embers. I will guess (or bet) that the engine is "tossing embers" occasionally all the while you are operating it, not just at "shut down"! It may be that the embers are just more noticable in the darker inside where you park it. If you ran it outside at night, you would probably see embers out in the open. Run it outside about 3:00 AM and maybe a neighbor will put it out of its misery. :^) Seriously though, the carbon build up inside the combustion chamber could be a factor in your loss of power. When a combustion chamber becomes coated with heavy carbon build up, these deposits can develop "glowing embers" or "hot spots" that can be an "auxiliary source of ignition" causing the intake fuel/air charge to "pre-ignite" which will result in a net loss of power from the engine. As the temperature of the combustion chamber continues to rise, more "embers" will develop until soon, you have nothing but "pre-ignition" and spark ignition takes place as "an afterthought". I presume that this old Kohler engine would normally "shut down" by killing the spark and denying the engine its source of ignition to "light the fire" in the cylinder. You state that it "does not shut down as smooth as normal. Never was great, though. Both times shutting it down, right at the end, it sputters". I believe that the embers in the combustion chamber are continuing to provide ignition (and these old carbs keep on providing fuel as long as the engine is spinning) after you "kill the spark plug" and that is why your shut down is "ragged, prolonged, and sputtering" (complete with fireworks). "Is the poor motor finally giving up?" It certainly appears to have reached a "plateau" in its life. You could probably rebuild the engine (if parts are available) and get another life cycle out of it. It will require a complete disassembly, clean up, and inspection, including "miking" all the components to see if they can be reused, and whether the cylinder would need to be "over bored" (with a larger piston to replace the obviously worn out, old piston). Could be pretty expensive if it's done right. Be a lot cheaper if you can do the lion's share of the grunt work (R&R and disassemble engine and reassemble engine). If you can't perform most of the neccessary work, you'll probably be better off finding a replacement engine to go in. If this sounds like "too much" to sink into a 1971 tractor (even though you've had it how long?), you might as well start hunting for a replacement tractor.

well - I was recently working on an old motor cycle - mechanical lifters ... we were thinking carb - but finally checked the valve clearance --- exhaust side was too tight... the motor would start perfectly and ran great... Then it got hot, started to run poorly, big loss of power, eventually hard to keep running - impossible to start back up. (until it cooled down). Wash rinse repeat - same story every time... we checked the valve lash - it was too tight ... once the motor warmed up the valves stayed open and compression dropped... valve lash reset, motor was a "little" more noisy - not much, but once it heated up it sounded perfect... completely hot - runs great - no power loss - problem solved good luck to you.

From the owner of a 2000 GT235 with B&S 18HP V-Twin Vanguard... Ditto what others have said about getting the _correct_ battery with Round terminals and 500 CCA capacity. To keep your battery conditioned when not in use for long periods of time I recommend a Battery Tender Plus. I have one. They work well  money well spent IMO. http://batterytender.com/default.php?cPath=11_2&osCsid=919c62601bf09f65d3d3feeebde57d89 HereÂs some very good info from a hardcopy I have of a GW thread from back in 2005. A guy had 2000 GT235 that ran fine, but the charging light was staying on all the time. Here is part of ÂEngine_TechÂs reply. "Do you have a 3-wire regulator or 5-wire? The earlier tractor used a 3-wire and a separate "discharge module" (looks like a M80 firecracker) to trigger the low voltage light. Later tractors used a 5-wire regulator, and the regulator controlled the light internally (no separate module). Look for good connections at all of these components. Look for wires backing out of connectors too. The light comes on if the battery or tractor system voltage is below 12.4VDC. ThatÂs pretty sensitive, so if there are any bad connections or voltage drops the light will come on." If you have the GT235 Technical Manual, check out pages 5-34 and 5-35. I have the original 7 year old battery in my 2000 GT235. My charging light has been coming on and off this year. But it starts fine and has no loss of power. I need to check my connections  as stated above. My Battery Tender Plus has helped keep this battery in good working order for 7 years. Ken  PA

With a grossly overfill of oil, this can happen: The crank hits the oil and churns it. The oil aerates, churning heats the oil, lubricity reduces, and oil pressure may falter and at cruising speeds. bearings begin to fail and cam surfaces may be damaged. Due to loss of pressure, hydraulic lifters may not support cam loads and excessive tappet gaps may appear.