Rattling gas tank

[goggles]

I noticed a rattle whenever I slowed to a stop. I thought it was the front fender since the rivets holes are worn. But today I realized it is the tank.

I thought I had left out one of the bushings for mounting the tank but they are all there.
They are only about 3 years old so they are not dried out.

I noticed the mounting hole at the back of the tank does not fit the bushing exactly. The mounting hole is oval shaped the bushing is round. Is this normal?

[Calvin Blackmore]

I noticed a rattle whenever I slowed to a stop. I thought it was the front fender since the rivets holes are worn. But today I realized it is the tank.

I thought I had left out one of the bushings for mounting the tank but they are all there.
They are only about 3 years old so they are not dried out.

I noticed the mounting hole at the back of the tank does not fit the bushing exactly. The mounting hole is oval shaped the bushing is round. Is this normal?

you have some pretty refined ears my friend
I cannot say if its an issue with anything in the tank esp when you state the mounts are newish

is it posible its in another part of the bike?

[goggles]

a little lean forward...

I heard the rattle because it is fairly pronounced.

I discovered it was the tank because I leaned forward and the rattle stopped/was not as loud.

I am going to remove the tank tomorrow to see if there are any signs of it hitting the frame but do not like messing with gas in a closed garage.

[Calvin Blackmore]

I heard the rattle because it is fairly pronounced.

I discovered it was the tank because I leaned forward and the rattle stopped/was not as loud.

I am going to remove the tank tomorrow to see if there are any signs of it hitting the frame but do not like messing with gas in a closed garage.

you can likely isolate the vibration by doing some stuff


for example if you were to squeeze your legs o and forward when th esound beegins would it stop?

I think that the sound is ewither a rubber part or mebbe a piece of wiring that is resonating at a certain frequency

[goggles]

nothing ventured....

I had not thought about other possibilities.

Will see if I can isolate it.

Read on another thread about running bike on center stand to try and isolate sounds.

Maybe I will try that.

thanks.

[chef1366]

Keep the tank full

[chuck hahn]

you can get some 1/2 inch thick peel and stick weather stripping and put along the frame where the tank sits to cushion and nest the tank down better. Also take your hand and put it on your gas cap to see if that is a bit rattly as well. Usually a new gas cap gasket solves this problem. On one of my 750s i noticed the gas cap cover was rattling..a few small squares of weather stripping under the cover solves that as well. Also check to be sure the two front tank mounts..the big rubber disks on the frame..are fitting snuggly into the tank mounts as well.

[FlyingSteve]

I have the same crazy ass rattle when I am downshifting to decelerate and it's fricken annoying and loud. Comes from the front somewhere and I haven't pin-pointed it yet. Let us know what you find out, Goggles.

[chuck hahn]

STEVE...try touching the glass on the guages when you are doing the manouver,,,the glass has a small paper gasket between the glass and the plastic guage housings..time and shrinkage could have let the glass vibrate a bit. You could maybe VERY VERY carefully add a drop or two of superglue in startegic locations to stop it if thats the problem..... keep us posted.

[FlyingSteve]

Ok, I will keep that in mind when I get out the bike again. I never hear it when I am riding normally or when I rev the engine... So it is weird.

[goggles]

so far nothing

I only had a few minutes over the weekend.

Put the bike on the centerstand and ran it.

Of course the rattle did not show up.

I will keep looking when I have the time.

Thanks for all the suggestions.

[JTsGS650]

Keep the tank full

What he ^ said. When my tank is just about empty I hear a rattleing too. I think it's the gas gauge arm or float inside the tank. After I fill it up the rattle is gone.

[goggles]

it will do for now

I had the bike out for a ride. No rattle until I was really low on gas.

So I have concluded a couple things.

1. I had forgotten that the aftermarket petcock had minimal clearance so I am assuming at times it makes onctact with carb cover.

2. The rear mount connection must have been somewhat loose to allow that contact.

3. A full tank of gas does make a difference.

If by chance something more definite shows up I am happy with those conclusions for now.

[Bill Alexander]

What he ^ said. When my tank is just about empty I hear a rattleing too. I think it's the gas gauge arm or float inside the tank. After I fill it up the rattle is gone.

I just got my bike back on the road after many years and over the last 2-3 tanks have noticed a rattle that starts when the fuel gets low. I have been suspecting the sender unit but came on the forum to get some ideas from others here. Looks like you have found the same thing JT and I would agree with your diagnosis.



This forum is awesome. The GSR certainly is a resource

[sedelen]

You never stated what type of bike it is.
I had a problem with big annoying rattle, I couldn't figure it out and it turned out to be the gas tank on a '79 GS1000E I had just got. There
was a cushion missing on the frame that the back bottom of the tank normally sits on,
it was gone. I stuffed a rag under the tank until I got a new cushion.
I found the missing one months later, sitting on top of the swing arm near where it bolts on the frame, I was fixing a flat tire at the time.