Advice on smoothing out 640 adventure

[rockclingerjim]

Hello all. I am after some advice on smoothing the engine down on an 2003 640. It just seems to me that it would be pretty hard work riding off road all loaded up with such a violent snappy engine. Every time i drop below 3000rpm it seems to want to shake itself to pieces!

Anybody know anything that could help this? I see that people have played around with jetting etc.
Any advice welcome,
Many thanks, jim.

[KiwiBruce]

Increasing the flywheel mass should help, don't know if there are any bolt on weights available, does any one else know?

[Island Hopper]

You could try switching your CDI to the low octane setting.... This is simply done by disconnecting the brown/black wire to the CDI under the right side cover. Don't disconnect it with the engine running...

I've switched mine and found that it mellows the engine a bit and you can always reconnect if your not happy with the results....

[kobold]

Hello Jim,

You can find lots of info about this subject in the thumper section of advrider.com. I used those info and changed my carburator settings, jets and bought new exhaust which helped a lot for vibration. Also, I took out the Secondary Air System and another system which slows the bike in 2nd gear. I added some weights to handlebar too but that didnt make a big difference.

Ozgur