vibration issues !!!!!! [Archive] - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums

: vibration issues !!!!!!


mymark66
03-14-2007, 09:02 PM
OK, here we go, my bike is running well, went 3 hours today, 2.5 yesterday. i have noticed some vibration, in handgrips, in my mustang seat, and feet, nothinmg drastic, but i really think it would bother me on a long ride, say 200+ miles. i have read about handlebar weights? better grips?re-balance tires? new tires? by the way my bike is a "96, 6700 miles, dunlop qualifier tires in good shape, stock grips, and as stated, a mustang seat, standard foot pegs, I have to do something, my hands do not like the vibes !! i have and am still learning a lot on this site, thanks in advance to all, please any and all comments, suggestions are welcome, if you reccomend tires , please name brand and size, same with grips. my girl friends "93 vulcan is identical, except for spitfire tires, front and rear, her bike has 8300 miles and less vibes than mine?

Sky Rider
03-14-2007, 09:12 PM
I would assume you are not the original owner?? If not, it may be that the bike sat in unfavorable conditions and the rubber gromets in the engine balancer have hardened up and are allowing the balancer to shift position as the gear rotates. Is the bike making any clacking or banging noises in time to engine RPM? This is also an indicator as are metal shavings in the oil.
Do the vibrations go in time to the engine RPM?
Dianna posted a pic in the maintenance section of the gallery on what a broken balancer can do. Fortunately, it is repairable, even the damage shown in the picture was fixed with a combination of JB Weld and Redneck engineering. Beavis was the person this actually happened to and his website has the series of pictures on how he fixed it. I dont' have the link handy but someone here will.
Hope this helps and don't get discouraged.

mymark66
03-14-2007, 09:24 PM
I am not the original owner, The rubber mounts may well indeed be "hard". the bike makes no unusual noises at all, the vibes are not in any rythm at all. the vibes are slight but constant, maybe a little more pronounced at higher rpms and higher speeds

Sky Rider
03-14-2007, 09:27 PM
Check to see how tight the motor mount bolts and the like are. It could just be that they are loose and are transmitting the vibes through the frame. That's much less drastic than the balancer gear.

mymark66
03-14-2007, 09:32 PM
OK, thanks, I'll check them out

Ccspinner
03-14-2007, 10:14 PM
You could add Ride on to the tires, It will also protect against flats and balance the tires.

Dianna
03-14-2007, 10:19 PM
One reasonably inexpensive fix would be The Kury Iso grips. They do a lot to tone down the handlebar vibrations.
http://www.customdynamics.com/motorcycle-performance-accessories/kuryakyn-iso-grips-motorcycle-grips.htm#METRIC_CRUISERS

You want the ones for 7/8" (6180) bars and the Goldwing ones are a bit longer to give you more hand room

mymark66
03-15-2007, 06:02 AM
is it possible to use the new grips and the bar weights?

Mark
03-15-2007, 02:20 PM
I feel like I'm more sensitive to vibration than my buds, especially with dirt bikes. I tried the liquid bar snake on my VN and didn't think it helped much. I also have the kury grips but my thumb still goes numb sometimes. Learning to relax my grip has helped a lot. Not saying that this is all you need - since you've been able to compare 2 bikes and find that yours vibrates noticeably more than the other.

The idea about checking the engine mounts is good. I also wanted to suggest that you check your plugs. Getting your bike jetted as close to perfect as possible will minimize the vibration. Perhaps you're running a bit lean due to the colder weather?

Good luck, Mark

JohnBoy750
03-15-2007, 03:33 PM
I have custom pipes, actually high quality chrome pickup truck tailpipes on mine. The vibration is more than factory but the owner before me put on some nice pretty thick foamy grips. I love them :motorcycl ! In combination of the grips and my Joe Rocket gel palm gloves I really don't have any issue with vibrations.

My .02:blah:

mymark66
03-15-2007, 06:42 PM
I have checked the mounts and they may be a little "firm", the tires on my bike are not a matched set and after talking to the original owner, they are 3yr.old - front, 4yr.old in the rear, so i am having me880's put on front and rear, 110 frt., 150 rear. I am hoping this will help? if not I will feel better about the tires anyway. As far as the plugs go , they are brand new, ngk iridiums, also i have completely removed the reed valve and associated air valve and hoses, removed "plugs " covering air screws (set at 2.5 turns) changed oil, greased rear splines and u joint, relocated r/r, added relay to coils, installed k&n filters, gel battery, installed a mustang seat, next i am going to replace/rebuild my plug wires. Other than the vibration, the only other "issue" is some "popping" of the exhaust on deceleration, this may have some correlation to the "vibes", so i adjust some and ride and so on. I really thank all who are and have helped me so far, this is a great site and working with folks who actually care about helping others is a pleasure in itself.

Mark
03-15-2007, 07:02 PM
Actually, I was saying to look at the plugs to see if you are rich or lean. You will probably always have some popping on deceleration, but if you feel the popping is excessive - that indicates that your slow jet is lean. You can adjust that circuit by turning the fuel screws on the carbs.

Mark

hyperbuzzin
03-16-2007, 02:35 AM
I have a pair of gel pad gloves also. Not sure what brand they are, but I really like them.
One thing I did to my throttle side grip, to be able to relax my hand while riding, was to add a Throttle Rocker. Now I don't really have to grip the grip to twist the throttle. I can even do it with my hand just ontop of the grip, giving my thumb a nice rest.
Most people put the Rocker on the outside of the grip (so it's closer to their little finger) I prefer it on the inside, next to my thumb.

Has the bike always had the vibration (even with the previous owner, if ya know) And, is it noticable when sitting still, or just when riding.

mymark66
03-16-2007, 05:33 AM
the plugs look fine, light brown, no soot ,carbon, and not "wet". as far as the vibes, the original owner said he never paid much attention to it, again, it is not bad, I am just trying to eliminate all that I possibly can, to gain a more comfortable ride

hyperbuzzin
03-16-2007, 06:54 AM
Have you checked the rear shocks, for possibly excessive air pressure?
That could cause a rough ride.
Over filled oil in the forks could too.

mymark66
03-16-2007, 10:30 AM
i have not checked the shocks, frt or rear, I'll do that this evening, what psi do you reccomend, and what number on the shock?

fergy
03-16-2007, 10:44 AM
The number on the shock kind of depends on your weight. I have mine on 4, with me at 260. Your rear air pressure on the shocks should be about 10% of your weight. So mine should be at 26 psi. You need to use a hand pump and very slowly and carefully air them up. Also your gauge will let off several pounds of pressure when you check them as they don't hold much volume of air so the pressure goes up and down quickly. It's a little hard to get them right but after several tries, knowing how much to overload them according to how much you'll let off when you check them with your gauge is the key. Don't use a compressor to try to air them up!

I don't think your front forks are adjustable, but I could be wrong. I believe only the first few years are adjustable.

I'd be interested to see if maybe your new tires don't calm your vibes down considerably. Maybe your old tires are sporting too much air pressure and have gotten choppy. Hopefully the Metz's will do the trick.

mymark66
03-16-2007, 10:47 AM
I hopr the new skins will do the job also. I will get a hand pump today and adjust my shocks as instruted, thanks for the advice

Foxhound
03-16-2007, 05:38 PM
I have an actual shock pump. It's basically a hypodermic with a guage and a pump nozzle. It only takes a tiny bit of air be very careful with any other kind of pump as the shocks can be blown easily from what I've been told.

hyperbuzzin
03-16-2007, 09:55 PM
I don't think your front forks are adjustable, but I could be wrong. I believe only the first few years are adjustable.

I'm don't mean air pressure for the front forks, just too much fluid. Not sure what the level of oil should be though.

And yeah, like it's been said, be careful putting air in the rear shocks.

mymark66
03-17-2007, 07:26 AM
thanks again for all the help, should have all this checked/done by the end of this coming week.