No spark I have a 1992 KX 250 that is still in showroom condition. Parked it 2 years ago due to overseas work and just went to fire it up and it has no spark. It was running when it was parked. I tried a new plug and did not solve the problem. Any ideas?

Wasted spark system. If fuel and electrical is all good/correct it is often the case in these symptoms that motor cycle spark plugs that although looking good and firing outside of the engine are breaking down and will not fire under compression pressures on a power stroke but will fire unburned fuel on the unpressurized exhaust stroke when the plug again fires in a wasted spark ignition system and when so firing the result is a backfire, usually quite loud.

I can not answer the question about the internal module battery. But wanted to suggest that when you changed the crank sensor you might want to lightly clean off the rust on the crankshaft pulley damper. The pickup sensor for the crankshaft needs to detect the magnet in the damper to fire the pulse. You have 10 years of rust build-up on that part.

I learned of this condition through working with old lawmmowers and tillers. In the off season the crank damper would rust and the engines would not fire. Sanded the parts and instantly there was spark to the system,

Yes

Not sure I am following your story, but you need compression, spark at the right time, and fuel for the engine to start.
If you know for a fact the plugs are firing, and you have compression, you may not have fuel at the injectors.

Change the fuse under the seat that is the start fuse do it and see how it's go

may be fuel or timing.

Please see my tip at http://www.fixya.com/cars/r5821173-doesnt_car_start_gasoline_engines . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

possible bad rings allowing excessive oil seep up and wash spark out on next fire. do a compression check, ck for proper spark, and fuel....hope this helps

sounds like your coil is packing in try the coil on another bike buddy if this works on another nike get back to me

You should have looked HERE (Edmonds.com) Brfore Purchasing this Vehicle! Check out the Complaints ans Recalls. There are a Number of things that it could be. have the Starter Relay Checked out. Then check your Relays.

yes it could and if there is little gas in the tank then gas might not be getting to the fuel pump