My S/G is only two years old so it should be good to go.

I like to recommend putting the ignition on a separate toggle switch. that way you can get the engine spinning then hit the ignition switch, its allot easier on the starter

Summary
 

This thread has run on much longer than I ever expected. Thank you to all that contributed, especially dvogtvpe. Here is what we have so far. Correct me if I am wrong and I will edit.

1. For safety reasons, govern the engine to 3,800 rpm. Maximum torque will be made between 3,000 and 3,400, so additional rpm are an unnecessary risk with a stock flywheel.

2. For a stock 12 hp. engine, it is best to run with a 16 to 17 tooth second gear. This can be accomplished with a 20% under drive. This is the biggest thing to make you competitive starting out. Running in a stock first gear is too low and second gear is too high if you have the standard 13/19 tooth gears.

3. For a 12 hp. engine, run a #26 carb. You get more torque.

4. For more hp. for a 12 hp. engine, bolt on an LP head. It is the easiest way to get an extra 2 hp. without rebuilding the engine. If you can't find an LP head, use a second generation head and have it milled 0.05.


Next year the engine will be rebuilt with a Kerber #3 cam, undercut valves, and a balanced steel crank.

then you probably want to budget in a good carb if you're going with the rest

What do you mean by a good carb? I have a new #26.

New pull results. I pulled in three classes.
Garden modified 10 to 14 hp., 23" tires, Finished Second
Heavy modified uncut, 16 hp., 26" tires, Finished Second
and Light modified uncut, 12 hp., 26" tires, Finished First.

Seems I still don't have enough power to get past the 14 hp. tractors. Doing good to finish second in the 16 hp. class though.
Maybe next year.

Just for those that are green with all Gens of Cub Cadet. 2nd Gen would be your 12hp Kohler' s or 14hp Kohler? I have been following this thread very close and I have learned a lot is good information. Thank you

after you put a cam in it with good valve work you will find a new carb won't preform like a "good carb"

2nd gen is what people call the 10 hp head with a dump area between the valves and cylinder, the so called LP head was really the first 10 hp head

Second generation still has the heart shaped area around the valves, but has the depression below the valves like the later heads. They are much cheaper than the LP head and will give you higher compression than later heads, but not as much as a LP head, which has no depression below the valves.