Motorcycle Repair: vibration, clutch basket, vibration problem

Question
QUESTION: I have a scratch built, I put together. It's a rubber mount-softail Sundance frame, with a s&s 113 SA eng. Higher compression and bigger cam than normal 113. I have 1700 miles on the bike. It has a vibration problem since new. I had the engine out and apart 4 times. This last time, instead of doing it myself, I had the eng. balanced and assembled by a professional shop that does Harley and S&S racing motors. I still have the vibration. I even tried a M6 primary chain tensioner. I just ordered a extra heavy duty front rubber mount and a isolation type upper mount. I'm wondering if the tranny could be causing the vibration. I thought it was the eng. because it's rpm related. If I accelerate it's fine. Once I decelerate or hold rpm around 2200 rpm- 2600 rpm it rattles the heck out of me, in any gear. If i'm standing still in netural and rev it up to 2200 rpm the back fender jumps all over. Could it be the tranny? If so what could it be and what should I check for.

ANSWER: Ride the bike down the road and when you get to the RPM where you get the vibration, shut the bike off and coast. Do you still get it? Do it again and put the bike in netural and coast, do  you still get the vibration?
Mike

---------- FOLLOW-UP ----------

QUESTION: Hi mike
Thanks for your prompt answer. I just got the bike back together with the new engine mounts and took it for a ride and of course no help. I took it up to highway speed and hit the kill switch. The vibration is the same with the engine running or not. I tried to put it netural but it's a little ruff to get in netural at highway speed, so I tried at slow speed and it didn't seem to have any vibration. So I guess your going to tell me it's not the engine. I guess tranny or clutch basket bearing. I kinda checked (not real good)the clutch bearing when I had it apart before. If tranny then what in tranny.

Answer
If you shut the engine off and dont have any vibration, then its not motor related. I doubt its the trans. I would start by check the tires since it related to a certain RPM. A bad tire will cause the problem, even though they look good. If youa re running spoke wheels, you need to check them for to make sure the spokes are within alignmant. Check your swinging arm and also the tightness in the neck bearing
Good luck and happy riding
Mike