rattle or ehh resonance --- what could it be...

[cobra407]

so i tipped my r65ls a couple weeks ago. didnt do much damage but there is a new annoying resonance at around 2000 rpms. sounds like a loose baffle in the tank? or mufflers? any ideas? thanks peter

[Barry]

I had a similar resonance when something was touching the underside of the tank. I took the tank off and put it back with a little extra padding on the rear rubber buffers. The noise went away.

[Bob_Roller]

There's no baffles in the fuel tank .

Check the center stand and possibly the side stand and see if they are contacting the frame or exhaust .

[Rob Valdez 79 R65]

Possibly a muffler.  Did you hit it hard enough to leave a mark?

Check your centerstand fasteners for tightness, while you are down there.  They come loose when you need them most!

[cobra407]

well it was the ignition coil. the bracket holder weld broke. i used some wire ties and reattched it to the frame.

[Bob_Roller]

If it's the forward coil mount, all of the grounds in the electrical system go through there .

You might get some odd electrical anomalies until it's welded .

[Rob Valdez 79 R65]

If it's the forward coil mount, all of the grounds in the electrical system go through there .

You might get some odd electrical anomalies until it's welded .

If it is a real LS frame, he won't have the troublesome front coil mount.

[Bob_Roller]

I over looked the LS part of the posting . [smiley=huh.gif]

[Rob Valdez 79 R65]

I over looked the LS part of the posting . [smiley=huh.gif]

Your post made me go back to see if he mentioned it.  I didn't remember, either.

[cobra407]

so are you all saying it needs to be rewelded ?

[Bob_Roller]

If you have the single dual output coil, it's not an issue, the '79-'80 year bikes had two single coils, the front coil mount was also the grounding point for the entire electrical system, if the mount broke, you'd get all sorts of intermittent electrical problems .

[Rob Valdez 79 R65]

so are you all saying it needs to be rewelded ?

If the bike is running fine, you probably have a real LS frame, and the ground may not be an issue if the coil mount broke.  I have never examined a post-'80 frame, so I can't be sure.  
Remounting the coil like you did should be fine.  
I have my front coil ('79 bike) strapped on with giant hose clamps I got at the hardware store in the plumbing aisle.  They have these giant rubber pipe connectors that come with giant hose clamps.
But I also have round coils that make this a little easier.

If you do have it welded, disconnect ALL GROUND wires connecting to the frame.

[cobra407]

thanks-- seems to run fine now-- peter