Hey guys. How's everybody doing?

I'm having trouble with my '05 DS650. Engine is stock. I have a K&N air filter on it, still boxed in. I did have an aftermarket CDI in it, a Dynatek. I didn't care for the ignition curve of the Dynatek, but it ran okay for a while. After a few months the bike would kind of sputter at high RPMs. The last time I rode it, it ran terrible. It would start cutting out at high RPM, then as it progressed, it would cut out pretty much any time I was on the gas for more than a second. It cuts out pretty harsh and sudden. It will drop a few thousand RPMs before the engine will rev back up again.

I thought maybe it was the valves, so I took it to my mechanic. He adjusted them, but it's still doing the same thing. I don't know much about fixing these things, so I'm pretty much at a loss.

Any ideas? I appreciate the feedback. Thanks guys.

 

Nobody?? =/

 

Have you tried putting the stock CDI back on?

 

Yeah I did put the stock CDI back in. I meant to put that into the original post, but forgot.

I think I just solved the problem though. I will have to take it out on a long ride to make sure, but I think it was the air filter. I had cleaned right before my last 2 or 3 rides, so I didn't think it could be cutting out from the air filter being dirty, but I just checked it today and realized that my pre-filter was breaking down and coming apart. it had mixed with the air filter oil and made almost a greasy coating on half of the air filter itself.

I cleaned the air filter and re-oiled it, put it back on the bike without the pre-filter, and it ran great. I test rode it the same way I did a few days ago and it did 100% better. It didn't cut out at all, and I went all the way to the max 7400 rpm the stock CDI allows.