She vibrates at a certain RPM

[J-Rail]

I agree w/what Chief said about the vibration. I have dual exhaust and it vibrated quite a bit. Makes sense, the pipes will vibrate off the motor. If they are attached to the bike firmly, the bike will vibrate.
I got some rubber spacers, loosened up the pipes, put the rubber spacers between the bracket holding the muffler, and the other end of the bracket at the rear pegs. Took it for a ride, cold and windy as hell, so I only went a couple of miles but I could tell a big difference in the bike. I guess it's 80% better. I figure the rest is probably "the nature of the beast".
PS- you don't even have to take the bolts all the way off. Loosen it up, cut the rubber washer and slide it over the top and tighten up.
Even if it doesn't help, it can't hurt. Hope it works for you.
Later
J-Rail

[edwar355]

Welp I got one more answer out of someone....what do yall think?
"I have owned my 1500 since new, the vibration around 50mph I would say is normal for this motor..I think it is just the resonance of the engine at this RPM...On my own bike I replaced the U joint( which wasn't defective) wheel balance and brg problems eliminated,etc. As for the remaining vibration by pulling in the clutch and the vibs go away.Gagets stated in an
e-mail it could be rubber harmonic balancers in the engine that got brittle may be the problem..Also I think worn motor mounts may contribute to the problem. My only concern is getting stuck somewhere...My drivetrain is ok so I'll live with a little vibration until I have to take the engine apart for some reason."

[edwar355]

I was wondering........I know mine has the defective clutch and I know it hasn't been changed because it is slipping when you get down on it real good.........could that be my problem??

[edwar355]

Welp I checked out my U-Joint today and its fine.......no play and moved freely all the gears and teeth looked fine as well...... so now I'm waiting for another good idea

[chief]

Yeah, anyone who has hardmounted their aftermarket pipes will have problems eventually. Personally, I couldn't stand the vibration from the moment I started mine up after mounting the pipes. I shut it down and fixed that problem right away.

[49Reo]

Regardless if it is the pipes being hard mounted that is causing the vibration, it is adviseable to rubber mount the rear mount; my 1500 had the vibration problem to the point it broke one of the mounting bolts on the rear mount. That much stress is eventually going to cause other fatigue related failures; it would really SUCK to have something major break in the middle of a good run.
Cheers, Regards, and such;
49Reo

[edwar355]

I'm going with the idea of the U-joint being messed up, after talking to several shops and other people they all said that this was a good place to start......I ordered one a few days ago and it will be in tomorrow....this weekend i'm going to put it in and see what happens. I'm going to go ahead and give you the link on the repair now before I lose the link http://www.gadgetjq.com/ujoint.htm       If you have any more questions feel free to ask

[edwar355]

Thats about the same pattern mine is going through.........what we are talking about on the pipes is if you look at the rear passenger foot peg where your pipes are mounted....is there any rubber anywhere to allow the pipes to move? If there is not you need to buy a right passenger foot peg for a 2000 Kawasaki Vulcan Classic this has the rubber mount built in (make sure you buy the rubber as well) BUT if you do so you will have to make a bracket for your pipes because it will be different than what you have............However if you do not buy the peg this is your other option.....................What I did when I had my Vance and hines was drill out the bracket that bolts to the foot peg and put some rubber inserts in....I bought the inserts at a local motorcycle shop for a few bucks...If you explain what your doing i'm sure they won't mind helping you.............So if your wondering why we are telling you to do this is, it is because the motor needs to move, as you know....before I did this little modification my pipes actually broke there welds at the heads and I had to go get them welded back into place.

Also another trick when buying the other bracket is if your ready to buy new pipes you can buy them for a 2000 Kawasaki Vulcan Classic (which is what i did) and get a wider variety of pipes. You can do this because the only difference between the two bikes is that particular bracket.     I hope this helps

[steve]

Desolate rider, some more details about the symptom: I don't have a tach so I don't know what rpm this is happening at, but...I accelerate in 1st and about 13-17 mph I feel the vibes. After this speed its gone. I shift to 2nd and about 23 to 27mph its back, then gone above 27. I shift to 3rd and around 33 to 37 its back, but above 37 its gone. This pattern continues through 4th and 5th. When I down shift the vibes occour at the same speeds, even though I am coasting, with no throttle applied. Also, the talk about hard piping is confusing. My pipes are Cobra's, they come out of the forward and rear cilinders and are supported by a bracket that also has the right rear passenger foot peg on it. Is this hard piped? Just boughgt this bike a couple months ago so I don't know if this problem is new or not.  Any info greatly appriciated!

[edwar355]

got one more Hi, I had the same bike a few years back with the same problem. It was u-joints that were worn. When I pulled in the clutch, this removed torque to the rear wheels and less stress on the driveshaft, when you accelerate this placed enough torque to take up the play, therefor eliminating the vibration. These bikes did vibrate naturally, but not like you are describing and your symptoms lead me to believe the your drive shaft needs some attention. I'm also assuming the engine is running fine and not missing slightly. Just an educated guess at this point, but something to look at.

I have a U-joint on the way for mine be here tomorrow....I wasn't going to go into it without having one sitting beside me.

[jcf]

Try checking your shaft drive.

[pcarrell]

Seems to make sense.

[edwar355]

got another reply (this one makes more since to me)
Since it is a specific RPM range, this indicates a harmonic imbalance in your engine...not the drive train. Also when you engage the clutch, you remove the load...and I am sure decrease the rpms as well so the vibration goes away. It is most likely to be an imbalance in the flywheel area, rather than an internal part that is warped or out of balance..Have you made any modifications to the bike, has it been this way since you got it or is it a condition that has just revealed itself? If it is new, something has slipped, ever so slightly as to cause this only in a specific RPM range... Good Luck! I hope you find this to be very helpful!

[edwar355]

I put our problem on fix ya.com and this is what one of the guys said.....
Hi,
You probably won't like this.
It sounds to me like wear in one of the input shaft bearings to the gearbox.
Unfortunately it can be worse than this because if the housing that the bearing sits in allows the bearing to move, then it can become oversize - allowing the whole bearing to rattle within it. It often only happens at specific speeds, and ends up with a mounting hole looking like a 50p in shape.

It may be something else, but vibration usually gets worse over time - indicating wear of a main bearing somewhere.

[edwar355]

Chief is right........those vance and hines i had actually broke the weld on the pipe at the head and i had a horrible exhaust leak

[chief]

Are they aftermarket DRIFTER pipes - using drifter right foot peg?

If so, you have the pipes hard mounted - which causes a ton of vibration. This is a problem in a sorts of ways. You have a rubber mounted engine being held by the pipes.

I suggest you get a classic right foot peg and fabricate a proper hanger. There are instructions in the mods/tips section of the web site. It isn't difficult at all.

This MAY not be your problem, but it is something that needs to get fixed in any event.

[edwar355]

Mine does the same thing......but I kinda got used to it but now that you have said something its made wonder a bit. Ill tell you what i've done....
I have:
Changed tires (one had a broken belt in it) but still shook after being replaced
I had vance and hines exhaust that were hard mounted (no rubber) on the passenger foot peg....Then i bought a vulcan classic foot peg (rubber built in) and Hard Krome exhaust for a vulcan classic (the one mount is the only difference).......still shakes

Just replaced the seat....gotta corbin with little padding and noticed that I can feel mine more from the rear.....I always felt it more in the handle bars....

So now I hit up google and have seen that it maybe a bad injector (kinda makes since) and also I found this http://www.gadgetjq.com/ujoint.htm which makes since ....so says my dad....he says a U-joint can sometimes have a sweet spot in them to...

Maybe we will get our answer soon............If I can find a U-joint tomorrow i'm going to be replacing mine

[steve]

Hey Friends,
I need some help. At a specific RPM range, through all 5 gears, my newly purchased 2000, 1500cc drifter vibrates. The vibration is like driving over a washboard and is a big mystery to me. I am new to the drifter and haven't owned a motorcycle for years.  I would appreciate any help you can offer.

Someone suggested that it might have something to do with my aftermarket pipes.

How do you check the fuel/air mixture?

Thanks for your help

-Steve