[kahiki]

Have any of you experienced a slight vibration at around 2600-2800 RPMs? I have a 2002 LowRider and have been chasing this problem for quite awhile. It seems to be more noticeable at times, sort of intermittent. My tires have been re-balanced, I've checked alignment, belt tension, primary chain (recently added a M-6, vibration was there before), all motor mounts and upper stabilizer link. Anyone else notice this? Thanks in advance.
Lenny

 

[Kags]

You had no vibes at 2600 -2800 before what?
The post sounds so simmiler to what my bike did.
You may be chasing a real nothing at all, but rather the motors actions given differant verables. Type of gas, air temp, how hot the motor is, humittiy, to name a few. Have you check for air leaks? Next time it seems like a lot of vibes turn the petcock to rev, to check for possible gas flow problems to the carb. even a vacum problem to the petcock .
Inless its a realy bad vibe I think it may be the nather of your beast.

 

[Thealien]

I agree with Kags, could be the nature of the beast. One of the complaints when they switched from FXR to Dyna was a little more vibration. How many miles do you have, have you always had the vibration...??

 

[kahiki]

Thanks to both of you for the reply. The bike has 8000 miles on it. I first noticed it around 1000 miles. Like I said nothing extreme, just worrisome. The bike has been jetted, SE air kit, SEII Slash Downs before delivery. I suppose it could be an air leak, but have no performance isues. It runs like a scalded ape with no lags throughout the RPM curve. I too have considered that it's just the nature of the beast. Possibly being amplified by something else that occurs at those RPMs. Just wondering if other have noticed it. Kags did you find anything with yours?

 

[Maj]

I tend to agree with the other guys. I've never had a tach on my bikes but both my '94 and '95 Evos shook the pegs pretty good at around 43 mph in 5th gear. When I rode a '02 FXDWG at the Biketoberfest demo rides I was surprised to find the same peg vibration at the same speed. My guess is normal HD vibration.

 

[kahiki]

At 43 MPH in 5th my bike would be lugging and I would expect severe vibration, also would be damaging to the engine. Mine occurs at around 2600 RPMs in all gears. It's mostly noticable at 60 MPH in 5th which is around 2600 RPMs.

 

[Kags]

Your not realy "lugging" the motor in 5th even at 40 mph as long as you dont jump on the gas. I can ride dowm the road at 40MPH on my bike at about 2000 RPM's all day, as long as its flat & I dont hit it. Lugging comes in under load. You want to play it safe- cool.

I only made my bike run better but Ive never got it like it once was when it was1450. At about 3000 miles on my bike after I had rejet the carb It was running so smooth for a wile seemed almost un-Harley like. Then one day I was showing off and hit the stock rev limitter in 3rd gear. The bike never ran as smooth after that intill I whent to the 1550 & change out nearly everthing. The 2600 to 2800 is where it was the worst. This was not a major vibe mind you, just had alittle more of the stock stuff than it did before I hit the rev limitter. Ive road other new Dynas that didnot have as much vibes, but the stock set-up helps the quill out some vibes. Free flowing pipes & A/C make for alittle more in the way the motor shakes. Oh course we also know not all motors are the same and a motor made next to blueprint with a good set of stock casting heads will run smoother.

 

[kahiki]

Kags, you just brought up an interesting point, the rev limiter. Around the time this vib showed up (1000 miles) I was starting to romp on it pretty hard at times. I know that more than once I hit the rev limit. The feeling of the vib has always made me wonder if it wasn't a timing issue. Do you think it may be possible that by hitting this limit it may in some way damage the ignition module?
Thanks,
Lenny

 

[Kags]

According to the Mo Co no. But what about the crank sensor? Or the MAS ? I dont know if somehow they could go out of cal. but I could never find out. Its realy funny its seem like theres nothing left to check and to hell with buying new parts, it ant broke so I wont fix it. Then again its not realy a issue for me now. If you find out anything be SURE to ley us know!

 

[kahiki]

Will do, Kags. Thanks for the input. I've heard of this from several others on other forums. As far as I know none of them have ever come up with an answer. It always seems to be Dynas though. One thing I find interesting is the way the engines are mounted. There is lots of play/movement in the lower mounts, but essentially none at the top isolator. I've seen a new top isolator made by V-Thunder that seems to be a much better design.