Engine vibration 4500 rpm

[Rk-rider]

Trying to find the source of vibration that peaks around 4500. Felt on foot pegs, exhaust, and handlebars. Vibration can be reproduced revving engine to 4500 standing in neutral. Completed torque checks on bolts, rebuilt clutch, rebuilt carbs and synced. Vibrates slightly less starting out cold. Any ideas?

 

[Rob S.]

Let's assume Suzuki.

What exact model?

What year?

I'm sure I won't be able to solve your problem; I'm just preparing the ground for those that will.

 

[Steve]

Let's assume Suzuki.

Easy there, Rob, don't go too far out on that limb. :-\\\

.

 

[Rob S.]

Come on, you 'wrenchers.'

Engine vibration. It doesn't matter Honda or Harley - just solve it.

OP - we're just funnin' ya. No offense.

 

[Steve]

Can't solve it until we have some more clues.

And, ... the easiest way to keep a Harley from vibrating is to pull both plug wires. :-\\\

.

 

[chuck hahn]

Tighten ( check ) all the engine mount bolts would be my first step.

 

[tkent02]

Can't be a Harley. He says it happens at 4,500 RPM.

 

[Steve]

Can't be a Harley. He says it happens at 4,500 RPM.

Maybe a V-Rod? :-k

.

 

[Big Rich]

81 GS450 L. To the OP: that is everybody's subtle way of saying you should put the bike in your signature.

A little bit of vibration is normal, but excessive vibration is not. Does the bike feel down on power at all? If so, I'd guess your camshaft timing might be off a tooth or two. Do you have the stock L bars? They look like huge tuning forks to me...... maybe heavier bar end weights if that vibration is just buzzing thru the bars....

 

[Rob S.]

easiest way to keep a Harley from vibrating is to pull both plug wires. :-\\\

.

I would've said turn the key off...but I've never ridden one.

 

[lrgguy]

Im having a simular issue ... after two hrs of riding your hands are so damn numb , you can barely hold on anymore !!
Going to check my motor mounts ...

 

[posplayr]

Im having a simular issue ... after two hrs of riding your hands are so damn numb , you can barely hold on anymore !!
Going to check my motor mounts ...

After getting my 1100E head ported (with 28mm 1150 intake) and flow balanced , a lot of buzz left my bike.

 

[Gorminrider]

Not sure about whatever bike this is, but my Suzuki twin has very little vibration anywhere compared to other twins I've ridden, and certainly not especially at 4500 rpm.

Big Rich has some good ideas there..handlebar weights do help a lot on handlebars (I found this out on a Honda, when I took them out)

 

[Steve]

I would've said turn the key off...but I've never ridden one.

Turning the key off will certainly stop the vibrating, but to keep it from vibrating, pull the plug wires.

Yeah, it's just a play on words, but that's all I have to play with.

.

 

[Guest]

4500-5500 is where they vibrate the most.

Its that way so that the balance is good at 7-8000.

If you can ride at 5000 for 10 minutes you should not be able to feel your hands or feet

One thing that helps is rubber shock mounted handlebars.

 

[Gorminrider]

What bike are we talking about? I can ride my GSX400 at 5000 rpm for more than 3 hours at a stretch and not have any "symptoms" except caffeine withdrawal....

 

[Rob S.]

I think the old Grab On sponge type grips are also helpful with 'numb thumbs'.

 

[Guest]

In my experience, once these engines feel smooth at 5k, chances are your engine mounts are all loose

All mine were loose when the engine wore the powdercoat down but it was much smoother These things should be ruber mounted!

 

[Gorminrider]

Seriously, I had no idea these bikes were all so different!

It might be interesting for me to attach a camera (with a high frame-rate in movie mode)to handlebar end or maybe a footpeg and see what the vibes are...I have cameras where you can turn the Auto-stabilisation off. Stuff like this intrigues me usually after a coupla coffees and smokes ...it'd be pretty interesting after carb-synchs and to compare various bikes that come within my ken.

 

[GregT]

In my experience, once these engines feel smooth at 5k, chances are your engine mounts are all loose

All mine were loose when the engine wore the powdercoat down but it was much smoother These things should be ruber mounted!

Never owned a British twin ?..........