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High rpm vibration?

11K views 8 replies 6 participants last post by  PeteH  
#1 ·
Took the bike on it's first highway ride. 03 Fatboy, 44k.

At higher rpm's either in 4th or 5th I felt a high frequency vibration through the grips. Speeds of 65+ in 5th, less than that and it was substantially less noticeable.
Goes away when the clutch is pulled in.
It was accompanied by what I would describe as a rhythmic, very dull thudding, not a spark knock or engine knock.

Just adjusted clutch and primary chain. Bike ran out beautifully.

It drove my carpal syndrome nuts.

Any guidance?
 
#3 ·
All tight, everywhere.
Pulled the cam cover for what I believe is the first time in 45K. Surprised at how good it looked. I will start assembling the parts for tensioner change in the next 5K or so.
I was hoping for an answer to my vibration problem but I don't think it's there.



Gonna dig into the primary side this week.
 
#5 ·
What does the back look like. I see pitting. I would change the tensioners and check oil pump for wear.
As for the vibration check comp sprocket as suggested!
 
#6 ·
Can you duplicate the vibration while stopped and the bike in neutral at the same RPM ? I guess what im getting at is have you for sure narrowed it to engine RPM only and not speed?
 
#7 ·
I had a similar vibration and felt a difference when I pulled In the clutch at speed ,but the amount of speed I lost after I pulled in the clutch made the vibration go away. I found a hill long enough to kill the engine and maintain the speed of the bike with the clutch pulled in and vala STILL a vibration in the bars. Had the front wheel rebalanced and it was gone. I had dyna beads and they didnt work so well for me.
 
#9 ·
Yes back tensioner is similar but still more than 50% left, so my thought is to change both at next service interval. Cam lobes were very nice and shiny, oil in the bottom of chest was perfectly clear with @ 750 miles on it.

Vibration drops off in time with engine rpm while bike is maintaining speed- down hill of the Skyway bridge. I am scheduled to balance front wheel this week.

Compensator check is next. Ran the VIN through the local dealer. They did "a bunch" of primary side work in 2010 (before they sold the bike to the previous owner at 40K). I will call back and hope they tell me what they did.

I will check runouts if I get no satisfaction from the primary side. At any rate I will thoroughly go through the cam chest at next service.

Thank you all for the replies!