F650GS engine chugging?

[mapperjay]

Hello,
I just picked up a 2001 f650gs with 42k miles and it has this odd problem of the engine cutting out between 3k and 5k rpm. It seems to do fine below the 3k tach, but then I'm drawing a fine line between the engine lugging and chugging. We replace a bad spark plug and it helped a little, but didn't do the trick.

has anyone else had this problem, or have an idea of what it might be?

Thanks!

[beemergirl]

Don't really understand what you are saying, you might want to further explain when your bike cuts out, when you are riding it?

The F650 likes to be around 4000 rpm or more when on the road. If you riding at 3000 rpms you are in too high a gear, downshift.

Anytime this bike starts cutting out, always check the battery cables and the battery. The cables seem to loosen with vibration and this is a common problem.

[mapperjay]

Good to know about the RPM--quite different from my other bike. But on that note, when is it best to shift (I mean aside from listening to the engine). 3K? 4K on the tach?

But I digress. Yes, while I am riding, once the tach reaches about 3K the engine will cut out, there'll be a loss of power and the tachometer drops about 1000rpm before going back to normal. This usually is more pronounced while riding two-up (I guess the engine is working more?) or with heavy roll on with the throttle (i.e. getting up to highway speeds).

I'll check the battery cables to see how tight they are. Thanks for the tips.