My brother has a 98 300ex and it cuts out and revs for a second then cuts out again. It has a new spark plug, carb is clean. I think the oltage regulator is bad because when it will run if you turn on the headlights is instantly dies. Also it doesn't charge the battery. Keep in mind that it does this quite often and is almost unrideable, however sometimes it will run ok but eventually starts acting up. Any help before he spend a fortune replacing parts.

 

Check your pm well get you going again

 

well an update. I bought a new voltage regulator and it fired straight up and run perfect for about 2 weeks then it's back to doing the same thing again any ideas?