buzzing from radiator area

[tmdoth]

The clogging of the vent hole prevents the venting of the gas tank...obviously. The best I can figure out, is that when the vent hole is clogged the vent won't function as it should, and you prevent air feom getting into the tank to balance out the vaccum being formed in the tank by the drain of the gas out from the petcock. Honestly I would have figured that it would have resulted in the gas flap being sucked tight against the tank, but obviously something is resulting in the flap rattling instead. My hypothesis is that it is close to the same principle that brings about the throttle release snarl that occured in my exhaust system. Something to do with increasing vibrational amplitudes. Could be something completely different though, I would love to hear other peoples thoughts on the subject.

 

[lowlife]

No need to haer anyone elses thoughts TM. You nailed it on the head if that is anyones particular noise

 

[lowlife]

Hey Willy

What do you call a drummer without a girlfriend?


Homeless

 

[Shlim1]

As far as the noise coming from the fan area (very common), you can check by doing the following: Start bike up (preferrably cold) and when possible, rev up to 1400-2500 rpm (this is where I had the issue). Look at the radiator fan from the right side of the bike, in the gap between the tank and the motor. If the fan is spinning slightly when the noise is persistant, there is a good chance that is where it is coming from. You can verify by holding or putting a slight pressure on the fan while the rattle is happening. If the noise goes away, you found your issue!! Bad thing is, the reason for the rattle, is usually worn bushings / bearings in the fan assy, and the fan runs $300++ if it is still available!! I have tried to counterbalance one that I had, and also tried to put some felt behind the fan to put some slight pressure on the fan, but it only made it slightly quieter!! Never got it to go away until I replaced the Fan!!

Good Luck!

 

[ron]

Wow!
I ran a piece of wire through the vent hole and the rattling sound is totally gone! I gotta admit, I was skeptical, but it definitely worked!
:dancingfool:

Can someone explain how clogging that little hole can create so much noise? Oh, and don't be afraid to use small words - sometimes I'm not too bright on the uptake.
:drunken:

I'll have to try that, I just have a rag stuffed in the top of the cap, can't see it when closed. Still not nearly as loud as this:

 

[MikeC]

Found a great solution to the fan buzz. I isolated the noise to the fan by removing the cover and shroud and an open flat hand SLAP to the radiator. This sound is the 2 cm or so gap from the fan post going in and out. Removed the retainer ring to find 2 finely machined washer/bushings. Picked up 1 washer thicker than both and sanded with it down with super fine bit by bit until I was comfortable. With the gap size vs. drag potential, oiled it up and it's never been quieter. I can actually hear the engine now! Been about a month since the fix with no problems. Plan to hit it with some oil whenever its accesable. If the only solution is to replace the fan then there's really nothing to lose.

 

[[email protected]]

Had the same issue on my 85 ZL. It was the gas cap. Stuck a short piece of peel and stick foam weather strip so that the cap presses on it when closed. Best two cent fix ever. Tony W

 

[samuelc]

Funny but mine just started rattling last week.

 

[R. J.]

The radiator is held on with 4 bolts/screws that mount to the frame. The rubber grommets have spacers in side & they can cause a buzzing sound if the grommets are dry rotted.