Ok, about a month ago I had my bike idling warming up. Ran in the house for a few minutes. Came back out and it had cut off. It would not start and I discovered that the ecu was burnt up. So, I found another ecu and plugged it in. when I flip the engine stop button on I dont here that little electronic sound. The bike started up but, I'm afraid its gonna fry another ecu. Is there something wrong with the RC valves? All help appreciated.

In general terms there are probably two key areas to look at, the RC Valve circuit and the regulator.

Disconnect the RC Valve motor and put a voltmeter across the battery, it should show about 12-12.5 volts. Start the bike, voltage should now be somewhere between 13.0-14.5volts. Any more and the regulator might be cactus, stop engine and replace. If the voltage is OK, slowly increase rpm, voltage should still be between 13.0-14.5 volts. More the regulator is stuffed, stop bike and replace. Less and something is drawing excess power. So you would need to go through a series of elimination by disconnecting parts of the harness.

If voltage was OK then go through the RC Valve adjusting procedure here -> http://www.nsr-world.com/tuning/250-tuning/engine/ . Making sure to check that the valves and cables move freely through the full range of motion, and have enough slack. Poorly adjusted or sticking valves or cables will make the RC motor draw extra current, and as the power circuit goes through the PGM this burns it out. When you conect and disconnect the TPS the motor should rotate and stop. If it all appears OK, run up the bike again and check the voltage through the rev range with the RC Valve motor connected. If the voltage drops off the RC valve motor itself could be stuffed.

Ok Worked on this bitch all night long last night. Did the process of elimination. Got a wiring diagram and traced all the wires. The red wire that runs from both ignition switches to the regulator to the main and ignition fuse has got lots of power. With the key switch on and I put the kill switch wires together, 1 or 2 of the 4 pins in the ecu start to get hot very quick. Could the regulator be bad sending too much power to the ignition system therefore burning the ecu? I also found that part of this red wire has been replaced with a piece of black wire. So I think this has happend before.

How many volts are you getting on the red (now black?) wire?

Alright, i've changed my thought. I think its the servo motor. You can turn the cables freely by hand but, when I connect the engine stop wires the servo motor should cycle. Mine does not. Is there anything that could cause the servo motor to go bad?[/list]

discrete component failure.

I haven't pulled one apart before so I don't know if they are brushless motors or not.

I'm guessing that these things just burn out their insulation, or the insulation fails with age.