Vibration

[Davew]

Hi all, went for a ride after balancing the carbs which definitely made the bike feel smoother. However I'm still getting a high frequency vibration around 3k and then the usual 6k. It comes through the fuel tank more than anything and I feel it if my knees are holding on to the tank. Just wondering if this is normal. Doesn't feel like the carb balancing has made much difference to it if any, wondering whether to do them again.

[fazersharp]

Who rides around at 3k and the answer for 6k is --go to 7.

Actually though I dont thing balancing the carbs will do anything for vibration as the smoothe refers to the engine more than vibration as a whole, and my bikes the same I think 

[Davew]

Ha ha. Fair enough.

[darrsi]

Read on here before where people have had loose or broken engine mounting bolts, might be worth a quick check.

[unfazed]

You could try loosening the 4 engine mounting bolts and torque them up again to 55Nm.

Another option to try first is to fit a large 30mm M10 washer  between the exhaust mounting bracket and the Foot rest hanger.

[Davew]

All seems fine but torqued up the bolts again anyway.

[Davew]

Interestingly I looked at the tank mounting bolt by the seat and noticed the whole mounting is quite loose. You can't tighten it up though as there's tubular spacers over each bolt. I think the rubber padding must compact over time and mean the bolts (and tank) can move slightly. I removed the tubular washer/spacers and tightened both bolts up and it was much better in terms of vibration. I'll see if I can get a new rubber buffer thing or make one that packs it out to the correct width so the bolts can be tightened.

[fazersharp]

How old is your bike - include it in your profile for it to appear on your username.
That bolt is supposed to be not fully tight as it is a hinge for the tank, you undo the 10mm or whatever it is that holds the tank near the bars and then the tank lifts up on than bolt you are trying to tighten.

[Davew]

It's 2001. the allen key pivot bolt is fine, it's the 2 mounting bolts that attach the bracket to the frame and the slatted rubber mount that won't tighten. Ive packed it out now and it fits tightly.

[noggythenog]

It's 2001. the allen key pivot bolt is fine, it's the 2 mounting bolts that attach the bracket to the frame and the slatted rubber mount that won't tighten. Ive packed it out now and it fits tightly.

Are we talking about a 2001 fazer fzs600 heres i cant fathom out what bolts you mean.




By your crotch is a big long allen ended bolt....this is the tank hinge.




At the other end by the stem about 25cm forward of the filler cap is 1 single bolt like fazersharp says which goes into the bike frame........the tank sits on top of 2 rubber bushes or half tubes that wrap around the frame to stop vibration and on mine are just cable tied around the frame....that is it for the tank really.......the front bolt goes really easy....if the bike is dropped the it gets damaged and does t tighten properly......i ran around with mine just half tight and didnt feel anything untoward.

[Davew]

It's these 2 bolts in the photo, attaching the bracket to the frame. The ridged rubber pad doesn't totally full the gap so the braket can move around on these 2 bolts.

Sorry pic is upside down for some reason!

[noggythenog]

Here be the offending article which ive got out the shed and ive flipped it upside down on purpose.




How does it compare to yours?




Mine all seems in order and wasn't causing any vibrations.




Out of interest have you tried anyone else's fazer coz maybe its just a quirk of the bike or like others say it could be engine mounts etc etc.

[Davew]

To be honest it's bettter now I packed the rubber out. I still get some vibration through the tank but I think that May just be normal.

I don't think there's anything wrong with the mounts, it could even be something vibrating under the tank.

[Davew]

Out of interest what bolts should I be checking for engine mounts, just to make sure im tightening all the right ones!  Is it just the 4 at the front?

[Arfa]

I had a similar thing after a recent air filter swap where I removed the tank. I'm fairly sure it was because I tightened the horizontal hinge bar at the base of the tank too tight. Loosening it a little helped a lot. I suspect all that rubber mount and washers is there for vibration dampening and isolation. Tightening the lot up too much will just couple the tank too tight and just transfer vibrations up.

[Davew]

Air filter case wasn't completely tight, so that was t helping. Reckon it's as good as it'll get now. Makes no difference whether the Allen bolt is tight or not to be honest.

[unfazed]

Check if the rubber cover that fits over the air box is under the tank hinge.

[noggythenog]

Out of interest what bolts should I be checking for engine mounts, just to make sure im tightening all the right ones!  Is it just the 4 at the front?

There's 2 at the back also...you need to take a good look under there to see them....tightest bolts on my bike when i was stripping it but if you're engine has been out previously then they could still be the culprit.

[Davew]

I think I've found the culprit.  I've had the bike stood and revved it to the vibration point, and theres nothing coming from the engine at all.  It's where the downpipes merge under the bike where I've patched a couple of small holes.  It seems to be coming from there and travelling up.
I'm going to be getting stainless downpipes soon, so hopefully that may solve the problem.  I'm guessing its just the resonance of the old pipes thats causing it.

[fazersharp]

I'm going to be getting stainless downpipes soon, so hopefully that may solve the problem.  I'm guessing its just the resonance of the old pipes thats causing it.

Stand by for a new "snapped studs thread"

Have a search on these forums for snapped exhaust studs, you are going to have to soak them for a few weeks first