I was out riding this weekend and my ride starting making a rapid banging noise when I let on the gas. The bike has 40,000 miles on it and I have been trying to get an ideal on where to look. The primary pulley feels tight, so I don't think that has come loose. I also check to ensure that the kick stand was not hitting the frame and that was ok.
Any suggestions would be appreciated.
thanks K.Martin

 

Could it be your rubber motor mounts?
http://www.jpcycles.com/catalog/2005...talog/0456.htm

 

What kind of gas were you using?

 

It could be a loose compensating nut, primary chain out of adjustment (streched). Do you hear it at a idle, my friend recently had a knock at idle and above, it was a loose compensating nut even though the nut felt tight by hand, you could see where the nut was starting to grind away the outer primary cover. We narrowed down the location of the knock with an engine stethoscope.

John TN

 

More info would be helpful with a diagnosis. Noise under load, which gear, accelaration, decelaration, idle, etc. Does it remain constant, increase with engine rpms or speed, etc.

 

Had primium gas in tank.

 

The bike was loaded with myself, wife and T-bag (approx 375lbs). The noise started on deceleration after riding for about 15 minutes. If I kept on the throttle there was no noise and if I held the clutch in the noise would disappear. Later on the noise would continue at idle speed when stopped at a light, but would slowwly dissappear while waiting for light to change. If I stopped for a break or gas the noise would go away, but return after riding for a short distance.
I had the bike out last night trying to replicate the noise, but it doesn't seem to happen riding one up.

 

Check the primary chain adjustment and then if that's correct, check the compensating nut. You need to determine what area of the motor the sound is coming from if you can.

John TN

 

Im thinking you may find your noise from under the primary cover. I would recommend removing the cover for an examination. You should see some kind of markings to go with the noise you are hearing. Good luck.

 

Another thing comes to mind, if any work has been done to the rear wheel ( pulley cover or change), check the pulley bolts, I've seen the wrong type of bolts used that loosened up after a few miles.