Whats causing this vibration?

[Grungy]

07 FXDB, slipons, Nightrider 02 ied, 5500 miles.This vibration is driving me crazy. Thought it was the drive belt, checked and re-checked, seems to be adjusted right. This is too wierd, it vibrates after I ride for about an hour and gets worse when making long turns. It only does this when the bikes hot. It feels like I have a nobby rear tire. I wonder if that Nightrider thing is making the 02 sensors send out a jacked up signal.

[hdnt1550]

Have you adjusted your clutch lately. That can give you the shakes if not properly adjusted.

[Grungy]

I have not done this yet. This would cause vibration when hot or cornering?

[frisco-rigid]

Hi Grung

Is this a rubber-mount motor.? If yes, then I'll just try to build on the info you've supplied..

The 02 sensor is the King of the closed loop and it commands the second-to-second Tune of the motor, so, if the sensor is reading or sending incorrect info when Hot and making the motor run jagged it just might be amplified by the rubber-mounting.. I'm guessing it did not do this before the new 02 sensor was installed.. Yes, no..??
Next time it occurs feel and/or look down at the motor and see what you can see..

The sweeping turn thing is cofusing though.. I wonder if it's aggravating that lean-angle sensor too..

Only when hot huh,, let's see what else you can tell us..

Oh Yeah, I forgot this--- when you say hot do you mean just full normal operating temp or waaaay more.?

[Wrightturn]

Hey guys,
Frisco and Wright talking EFI ?? I think Frisco is on target. Not sure exactly how much the Nightrider takes over. The 07 would (will??) get hot from being super lean and default into open loop mode. You go from too lean to super rich. A rubber mount bike going super rich would have the rough symptoms.

Check the plugs for black wet look. When the sensors fail or wiring comes loose this will happen. I am sure Nightrider has dealt wih this and can give you volt/ohmeter readings to test. Like Frisco asked "how hot is it?"

I have an A/F meter now and have welded bungs into headers for a carb Dyna. The findings will be interesting for both carb and EFI. Going to a swap meet to look for headers. My plan is to eliminate dyno crimes that happen on stage 1 efi. So far have only been surprised about decel pops. Will post when I know more.

[Grungy]

Thanks for your reply. I think I will remove the IED's and see what happens. I will let you know. Thanks
Rubber mounted, normal temp.

i have a 07 ultra with a sidecar - vibration starts after a full hour at over 70 - then last all day - but only when im really on it - at lower throttle position, no vibration - its not screwing up the mixture since its still got full power - but there is a definite increase in vibration once its all warmed up, especially if i run over 80 for extended time. runs perfect just shakes & only with the throttle up. if i back off the throttle just a tiny bit the vibration goes away - but whats the fun in that when in a hurry on I35? also its not a engine lean heat issue - its when the whole engine and trans are heat soaked issue. running around town the cooling fan will come on every so often and that wont bring on the shakes - only really getting on it for a hour will make it shake - and once it starts it keeps it up all day till it sits for 6 or 8 hours then the shakes are gone.

oh, its worse when making long right hand sweepers at speed - you know over 80 with the sidecar tire just about to lift up. but once it starts its all day till it cools off for over 6 hours.

any ideas?

[Grungy]

Whats wierd is, the bike ran great for 5000 miles or so, then one day the vibration started, it's kind of pulsating, on and off. Seems to be worse at higher elevations.

[4cams]

If it's surging, I would check the intake for a loose fitting. That should be easy enough. My bike was vibrating more than normal at 3100 rpms, it was a broken exhaust mount on my Thundertheader. Other times this has happened on my FL only in a different spot. Check your intake manifold if it's surging.

[Grungy]

Not really surging, feels like I'm riding on a bunch of little speed bumps, vibrates the whole bike, foot pegs, handle bars, my rear, maybe it's running on one cylinder. This is at normal RPM's. When I go full throttle it runs good.