Why does my Petrol tank vibrate so much? Tips what check?

[marty400]

Hiya All,

Why does my Petrol tank vibrate so much? Tips what check?

Nc29
Standard airbox, carbs etc set up

My CBR600f's petrol tank is dead still, my NC29's petrol tank vibrates like crazy beneath me. (Not so bad when mostly full of course.)

Anything obvious to check?

Does the petrol tank actually sit on the air box etc? or is it suppose to be suspended above everything with only the petrol hoses running off it into the carbs and overflow etc?


The rubbers on top screw mount and bottom mounts are there
The rubbers on sides on tank are there as well, to stop touching frame

I've had a quick look with a flashlight, the petrol tank is not touching anything, on outside inspection at least

Please advise, be good to know what to look for!

Regards
Martin

[Davez29]

First thing I thought of was those front side rubber mounts but you have them. The only thing you don't mention is the foam stuck under the tank, have you got that? When my tank vibrated it was those side mounts not on. Only other thing i can think of is if you have front and rear mounts correctly spaced its the airbox is not on correctly. Dunno really.

Just a thought, remove the air box or just the lid and see if that helps.

[marty400]

First thing I thought of was those front side rubber mounts but you have them. The only thing you don't mention is the foam stuck under the tank, have you got that? When my tank vibrated it was those side mounts not on. Only other thing i can think of is if you have front and rear mounts correctly spaced its the airbox is not on correctly. Dunno really.

Just a thought, remove the air box lid and see if that helps.

Hiya Again DD! 8)

1) That Foam under the tank - is it all around, or just where the Carbs are?

2) Front and rear mounts correctly spaced - What should they have? Spacers? Can you advise?

hope you can advise

Regards
Martin 8)

[Davez29]

As it happens I'm busy trying to find out why my bike has a damp problem, starting on three and taking a few minutes to get to four. So have my tank off.

http://i62.tinypic.com/ic8j6q.jpg. sorry the forum is struggling with the picture size and I have no time to convert, so hope the link works.

The front and rear rubber bits should have steel spacers in them so the bolts grip them and not the tank or rubber bits.

[marty400]

Thanks DD,

Great photo!

I'm lifting the tank tomorrow, and see if I have the extra foam at the top of the tank.

May also try that "No airbox top" idea, and see if the petrol tank is sitting on top of the air box.

Regards
Martin

[marty400]

Any tips on that sodding tiny bleeder hose? if was a bastard to make sure it was in when putting the tank back on!


Regards
Martin