Small Engines (Lawn Mowers, etc.): Blades quit turning, electric clutch, overhead valves


Question
I have a White LT1850 46" rider with a 20 hp v-twin, overhead valves, dual carburetors. It was purchased new in 2002.

A few months ago, without incident, the blades quit shutting off when going into reverse. I wasn't too concerned, as it was kind of a hassle anyway as cutting my lawn requires a lot of stopping and turning around. A few days ago, while going forward, the blades just stopped. I push the knob in and pull it back out and the blades again start turning. I might go 20 feet, it may be 200 feet, and then again they'll stop again on their own. I can do this over and over.

All the pulleys on the deck appear to be straight and turn freely. The belts are all tight and in good shape. The battery reads 12.4 volts at rest, 14.4 when engine is running. I've checked all the connections I can find and all are tight. Seat contacts are clean and nothing is bent. How about the electric clutch? Looks OK. My grass is growing very quickly. I don't want to use my push mower on 4 acres. Can you please help?  

Answer
Post your tractor's model numbers so I can see if the clutch is adjustable, adjusting the gap
might be all you need, but I would look at a voltage problem as well, as well as a poor ground
in the front area.  Check the voltage running with the clutch engaged and see what it reads.