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Buzzing

3K views 19 replies 5 participants last post by  KCW 
#1 ·
So, bought this bike,2007 v star 650 classic. 9500 miles. I put on new tires, changed all fluids, engine, final drive and brake and new pads, pod kit, new exhaust, synced carbs and now it runs great. I am having issues with buzzing, hands, pegs and seat in each gear when giving hard throttle. Then it cruises real good in 5th, about 50 mph nice and smooth, About 60 it comes back. Is this normal or do y'all have any ideas?
 
#2 · (Edited)
I have the same bike 2 years older.

<= photos in my garage page, click on the thumb nails in the garage page to see full size photos.

Without riding your bike myself I cant say if what you are experiencing is normal, or if something is out of balance on your bike. A v twin engine is not inherently balanced, so you will get some vibration.

My bike is fully stock. Winding up thru the gears its pretty smooth unless I really crank the throttle going up a good hill, then I can feel the engine pulsing on each revolution of the crank.

For a reference point, riding at a steady speed in 5th gear at 50mph on level ground the bike is very smooth. If I creep the bike up to about 60 I feel some vibration in the engine. Its there up to about 62..65... then it smooths out again all the way up to 85mph.

Its a good indication when you are riding in a 55mph speed zone that you have crept up to 60 without having to look at the speedometer.

The other thing you should know, even though the 650 is a V twin, its not a long throw engine like a Harley. The 650 piston throw is about the same as the piston width, so its really a hi -reving engine. Not 10k rpm hi like an inline 4 cylinder sports bike. You can lug the 650 down to 25mph in 5th gear if you want if you are riding at a steady speed, then give it some gas and let it wind out all the way to 100mph (about where the rev limiter kicks in and shuts off the ignition).

You can really get on the throttle, the peak HP in 4th gear is at 55, and the peak in 5th is about 75mph. Im not sure what your intake pods sound like, but with my stock intake the engine just growls at those peak shift points, and begs for more.

That brings up another point: with your modified intake pods and aftermarket exhaust did you put bigger jets in the carbs and adjust the PM screws out a bit? If you leave the stock jets in the bike it will be running a bit lean. That would tend to make it knock if you let the RPMs get too low in any gear. If you havent changed the jets you should. Running the bike lean in the long run will burn the seats of your valves, and if you ride it hard it will melt the center of your pistons clean thru.

Have to add, if you are not aware, according to Consumer Reports customer tracking, the Vstar 650 is THE most reliable motorcycle you can buy. Congrats on your new ride. It should be good for at least 100,000 miles on the odo.

If you think your VStar is vibrating, stop next to a full size harley at a red light. I was watching a HD in front of me a few weeks ago, his hard bags on the fender were shaking sideways like he was mixing paint, and his handlebars were bouncing up and down about 1/2 an inch with the bike idling.
 
#3 ·
Being a used bike, it sounds like you went through things like I would have. As KCW pointed out, if you added exhaust or pods, you should have changed the jets...changing both, you definitely should have changed the jets along with adjusting pms screws.
Another simple thing, fairly low mileage, 10+ year old bike...run some seafoam thru it along with some stabil (marine for ethanol, red for storage and upkeep) to help clean things out and swap the fuel filter while you are at it.
How does it idle throughout the rpm range? nice and smooth, or mirrors look like they are shaking at certain rpms?
Might take a few minutes and hit a few key bolts/nuts with a wrench just to be sure....any frame to motor/drivetrain bolts.
Vibration on 4 wheelers coming in around 60 and leaving around 65 usually indicates a tire balance issue, which can shake the steering wheel.
Warped brake rotors on 4 wheelers will also cause some shaking, I have to assume it would be similar on a bike, but not sure to what extent.
 
#4 · (Edited)
Alpha: Ive heard other people say the steady speed vibration or buzz on the 650 at 60mph is normal.

I think its a resonance between the engine and the frame/mass of the bike - or maybe the engine mounts resonate at that rpm in 5th.

Im on my 3rd set of tires on my 650 (put 31,000 miles on it) and its always been there right at the same speed.

Its not excessive, the mirrors dont shake, but you do feel it.

Like I said, its a 'feature' letting you know you are speeding in a 55 zone. :^)

BTW, I agree with the SeaFoam - if the bike sat for several months without being used, there could be some gunk in the carbs that needs to be washed out. A couple tanks with Seafoam will do that without needing to take the carbs apart to clean them.

One other thing I have found: if you can get ethanol free gas my bike seems to run smoother on it. I checked the mpgs carefully on a couple tanks full, and the mileage was exactly the same, but it just seemed to run better. Also: I assume you are running regular octane. The bike is not setup to use premium. The compression on the 650 is actually pretty low - 9:1 (just looked it up). My Royal Star is 10: 1, but it also uses regular octane.
 
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#5 ·
One more thing: when you changed the rear tire did you wipe down the drive shaft spine and re-grease it?

You need to use a 60% moly paste on the splines. If you put regular bearing or axle grease on them it will get thrown off, then your splines will wear quickly.

Most bike shops know this (if you had someone else change the tires for you), but its something to be aware of. There are actually 4 splines in the drive shaft, you have to pull the nose off the rear gear assembly to get to the other three.

If they are properly lubed with 60% moly you should not have to lube them every time you take the rear wheel off. The splines will last the life of the bike. Its only a problem if someone wipes the moly off, and puts bearing grease back on.
 
#6 ·
Thanks, yes The jets were changed and pms screws adjusted, lol, I should have added more. Had the tank flushed and new filter, I cleaned out or replaced everything that was bad. Except for the frame, tins and wheels., I had the new tires and tubes put in by a mechanic shop. I don't know about the splines. Thinking I may take it to the dealer and have them recheck the balances and the splines. I guess it wouldn't hurt. I've come this far, lol.
 
#7 · (Edited)
before you take it to the dealer:

if you have a wheel out of balance you can tell by pulling in the clutch at 62mph. If its the engine the vibration will stop. If its a tire out of balance the vibration will still be there.

The splines will not cause a vibration if they are not lubed with the proper Moly paste, they will wear out faster and eventually will slip and spin on each other. If you had the tires changed at a proper bike shop they should know a shaft drive needs 60% moly paste. If you took the bike to Six Finger Jim's back alley motorcycle shack, then stop by an ask Jim what he put on the splines. If they are not slipping (like a slipping clutch with a horrible noise) there is no reason to take the back wheel off the bike and check them.

An air cooled motorcycle is a noisy beast to begin with, and unless you get an inline 4 cylinder, or boxer engine (inherently balanced by design) like a goldwing or BMW, there will be some vibration at some speeds, and always when you have the throttle WFO.
 
#10 ·
The other thing to try, some new riders have a death grip on the handlebars until they get comfortable with the bike and start to relax a bit.

If your hands are getting numb relax your grip and lean forward to balance against the wind.

Also if you stick out your index finger and rest it on the brake lever, then you are holding the throttle steady with your finger and rolling it under your fist, instead of using your wrist and forearm all the time to hold the throttle position.

A lot of new riders dont realize for a while that at riding speeds a motorcycle is self balancing. Its literally impossible for the bike to just fall over at speed, unless you lock up the front wheel. If you let go of the grips (with good heavy tires) the bike will go straight and balance all by itself. All you have to do is steer the bike where you want it to go, so the constant tension in the hands is not necessary.
 
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#13 ·
very nice.

took me a minute to figure out what is missing...

where is the air filter located?!
 
#15 ·
but where is it? under the gas tank like the Royal Star? on the left side of the bike?

It makes the engine look very different.
 
#17 ·
I should have quoted Newton: A motorcycle in motion tends to stay in motion, unless subjected to external forces.

"Just fall over" implies falling over by itself, for no reason.

Even an 18 wheeler can get knocked over (by a train).
 
#20 ·
There is a photo of my Royal Star in my garage page
<-- over there. click on garage, click on Ursa, then in the garage page click on the thumbnail again to see the full size photo.

Its a water cooled V4, the early ones (like mine) have carbs. The air box is the air filter enclosure and it sits on top of the carbs and below the tank.

Its a pain to change the air filter the right way, you have to take the gas tank off, then disconnect the air box from all 4 carbs with literally no room to get a screw driver on the clamps, then take the air box out of the frame and take 8 or 10 screws off to open it.

When I changed the airfilter last time I just pulled the tank and took the 10 screws off, and then you have to brute force the cover off (while its still attached to the carbs on the bottom). It can be done, but I think you risk breaking the plastic.

I know from taking the airbox off my 650 to do the valve adjustment it was difficult (20 minutes) to get it back on and to get the two clamps to seat correctly. Im guessing its 8 times harder with 4 carbs.

I like the way the V4 engine looks on the Royal Star, its like two 650 engines bolted together side by side. It looks similar to the VS650, except they hid the air filter... like yours now.
 
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