Phantom noise.

[fiddle mike]

I'm hearing a medium pitched buzz, that sounds like it's coming from the area of the timing belts. It sounds almost like a fly buzzing against a window. I haven't been able to pinpoint it. but I first noticed it after adjusting the belt tension.
I replaced the top radiator hose about the same time.

I torqued the bolts behind the radiator that some people have had trouble with, while I was at it.

Has anyone else experienced similar?

[Jess from VA]

Sounds like the buzz (rattle) bolt to me.

[fiddle mike]

Sounds like the buzz (rattle) bolt to me.

I torqued those bolts when I replaced the top radiator hose.  I removed the horn mounting bracket, though, so that's worth a re-visit, at least.

[Jess from VA]

Sounds like the buzz (rattle) bolt to me.

I torqued those bolts when I replaced the top radiator hose.  I removed the horn mounting bracket, though, so that's worth a re-visit, at least.

Well when mine started driving me crazy, I torqued it hard.  It only decreased rattling a little bit, so I went back and torqued it as hard as I could physically pull (nut squealing on the threads).  I think I was pulling/bending the frame members the bolt runs through together.  The rattle is not the bolt, it is the internal spacer the bolt runs through, inside the frame members, that rattles.  Some have got in there and added a washer inside the frame members and/or spooged RTV sealant inside the spacer.  

I suppose it could be your timing belt tensioners or the radiator itself (top bolt?).  When noises start right after maintenance, the noise is most often related to that maintenance.

My rattlebolt noise just started out of the blue, no precipitating factor I could ever discover.  Irritating as hell though.

[fiddle mike]

I'll be looking at all that stuff.  I was told that the belt leaves deposits on the tensioners that can cause  noise, too.  I have over 200K on the bike, so ordered new tensioners, anyhow.  I'm headed to Oklahoma, Sunday.  I rode 800 miles with the noise, two weeks ago. No problems, but that kind of thing drives me nuts.

[Patrick]

You said you didn't notice the noise until you adjusted the belts.  What did you set the belts at ?
I find leaving them loose [ 3/8"] keeps them quieter. These engines 'stretch' a lot as they get warm.

I'm not a Wing guy but read somewhere that the belts on them are set at 1/2".

[fiddle mike]

They're set at whatever the service manual calls for .2"- .3", I believe.  I'll try a little looser and see how that works out.

[Ricky-D]

Figuring the belts will either wear or stretch is an appropriate reason for readjusting the tension.

Let the springs take all the work out of the job.  Take all the slack out of the tension side of the belt

and let the spring take up all the slack on the relief side of the belt. So simple and full proof. These cam belts need

no tension whatsoever, they simply need the slack removed.

***

[Chrisj CMA]

They're set at whatever the service manual calls for .2"- .3", I believe.  I'll try a little looser and see how that works out.

If you did it by the book, chances are the belts are making the noise.  Loosen the a tad, probably will quite right down