Take the seat off and make sure the two nuts that hold the tank on are secure. If they are secure look between the frame and the tank up front , there shoud be a rubber cup on each side that the tank slides on to.

 

Sure it's not the front fender?

 

are even the headlight and tach mine rattled there for the longest time at certain rpms

 

theres a recall on the 02 gas tanks. under the tank is a piece of rubber coated foam. move it around so theres a slight bind on the tank when you push it onto the rear tank studs

 

If the two nuts links refered to are snug and it still rattles then loosen them and push forward on the tank and snug them back up. That puts a little preload on the supports and it stopped mine from doing the same thing. Really annoying - kindof like a buzzing or harmonic "tinny" vibration at certian engine rpms. I pushed down on the back of the tank and it would stop.
Careful though - it doesn't take too much to wring one of those studs off that the nut are attached to. Didn't happen to me but I remember one or two guys having to get the remains out with easy-outs and replace the studs.

 

There is also a bolt on the plate that Pwrcrusr is telling you about. It holds the plate to the tank. It could be loose. That plate came loose after I swapped my tank. I couldn't get it to tighten backdown like it was the first time, but it doesn't rattle.

 

Thanks for your input. I'll give these suggestions a try and let you know.

Update: Checked the rear tank bracket, and it was loose where it bolts to the tank even though the bolt was tight. The problem is the stem on the bottom of the tank that the bolt goes in sticks through the big rubber isolater too far. I put a spacer between the big rubber isolater and the small round rubber washer that has the metal cap type washer and then the bolt. Bracket now tight and the two nuts at the other end of the bracket are tight.

It's too late and too cold to crank it up and take it for a spin down the block to see if it fixed the problem, so I'll do that tomorrow weather permitting. I'll let you know what happens.

 

If it is the tank you may have solved it; however
I had the same problem on me 'o2. I popped the tank,
checked the bracket & rubber spacers, scooted the tank up,
back, smoked a cigarette, etc to no avail.
Me final solution was a strip of cardboard between the tank
and the bracket that bolts to the frame. Didn't even have to take
the tank off. I have had zero rattle since. Good ole' hillbilly engineering keeps me bike quite and is invisable to the eye.
Hope you got it fixed. Them rattles is annoying.

 

Well, that was the problem. No more rattle.

I'm not sure why Yamaha didn't fix the problem since all they had to do was shorten the mounting post on the rear end of the tank. That's all I did by putting the spacer in.

Thanks for all your great suggestions which helped me to figure this out.

FF

 

I can attest to the fact that on a '02 model if you tighten the tank to much on the mounting post vibration will weaken the spot welds that fix the mounting plate to the tank & your tank will develop a leak.

If you want more info do a search, this topic was covered many times during the '02 recall for the tank washer & bushing.

 

quote:Originally posted by Churchkey

I can attest to the fact that on a '02 model if you tighten the tank to much on the mounting post vibration will weaken the spot welds that fix the mounting plate to the tank & your tank will develop a leak.

If you want more info do a search, this topic was covered many times during the '02 recall for the tank washer & bushing.


Do you know if the 03 welds were improved? Maybe I need to put in a thinner spacer that will just barely remove the rattle and still allow some movement if possible. What do you think?

Extended warranty, I knew there was a reason. Spacer gone by the time it gets to dealership.

 

Try this: Return the post mount to its original configuration. use a piece of reinforced gas hose approximately 5/16 inside diameter & cut two pieces approximately 3/16" thick. Install on the two frame studs. Use some rtv silicone or blue locktite on the studs, install mount plate & nuts. Tighten nuts so they are good & snug but not so tight as to mash the rubber spacers.

Check the fit of your seat. The front rubber of the seat touches the mount plate, if it won't latch grind a little off the seat rubber untill you are happy with the fit up.

If you still have a little rattle score a thin piece of rubber or plastic hose that will fit tightly over the post under the tank & install. That should do it, at least it did it for my bike.