My 02 DS650 Baja has started this cutting out at around 7500-8000 RPM, it used to do it at about 10,500. It's got the ron wood box and dual Keihin FCR 39mm carbs. I've been thinking it was fuel related, but it does it regardless of whether it is free wrapping on the bench or if it's out on the dirt with a load on it, don't matter what gear. I'm thinking I need an ignition box. Anybody got any ideas?

Thanks

 

plug in a stock cdi, and see if still is cutting out, stock is 7700rpm? if so check fuel filter in tank then fuel tank vent to see if pluged . hope this helps.

 

Ok, I'll give that a try, I don't have another CDI, but I'll check the filter, I already checked the vent, didn't realize there was a filter in the tank. I'm gonna clean the air filters for good measure too.

 

The ron woods CDI has no rev limiter. I hope you are using a shim under valvetrain if you are running up to 10K+ RPM. Otherwise you are floating valves. Not good.

 

What was the problem?? fuel or cdi or weak or broken valve springs???

 

I had a woods box fail on me a couple of years ago. Mine did the same thing - cut out in the same rpm range.

Even throw it was 3 years old they still covered it under warranty - now thats service !!!

 

It was fuel, the carbs were both running over, I discovered by accident that if I run it without the filters it ran alot better, so I decided to replace the dual FCR setup with a stock carb, I'd rather have it be a little slower and more dependable. If anyone wants the FCR's, they are posted in the classified section. Now that it has the stock carb on it, it will bury the tach again.