While out riding yesterday, I heard a very wierd, very brief whistling or buzzing like sound from the back of the machine.
It only happened a few times and it was less than 10 seconds long.

Any ideas?

It was very wet and muddy. Riding slow, as we had the kids out with us. At first thought it was the 360, but when wife pulled away it was def. from the BF.

 

Loose glass-wool packing in the exhuast muffler sometimes makes the whistling noise.

 

any way to bore out the exhaust?

I noticed on my friends Grizz that a tailpipe comes out of the exhaust and you can remove said baffles...

 

Never tried on BF, but it can be done. Not easily though. It all depends how much hassle you want to go through trying to accomplish what you have in mind. Before that, you should know that tailpipe noise level is regulated in some areas. Like where I ride, it is limited to 96 decibel max for 1986 and later year bikes and 101 db for pre-86 bikes. Park/forest rangers carry the db meter in their truck and can cite you if you are over the limit.

The BF tailpipe is a one-piece, packed and welded at the factory. In old days, we cut off the end cap piece of the tailpipe using a torch or hacksaw, gut it out and weld back on. The exhaust sounded like $500 Pro-Circuit pipe and attracted people's attention real quick (which can be bad sometimes).

 

yeah, not going to bother. I'm thinking about the Dynatek CDI though

 

Are you sure the noise was coming from the exhaust????

I think your belt was overheating or wet (less likely) and was slipping. You said it was very muddy.... did you use a low range????

No offence, but i've seen many people just trying to go ***** out in deep #@&!# and in high range you'll heat that belt in no time. Same thing if some water gets in there.

The factory exhaust doesn't have packing like aftermarket, so there is no way it would just wistle like that.

Anyway I would check that belt, and maybe tighten it up a bit.

I have an 06 BF 650. Hope this helps.

 

If the noise is indeed coming from the exhaust, the welded baffle inside the muffler canister might have come loose. It would make a metal rattling noise if you shake the muffler if the baffle is loose. Also, check the drain bolt on the bottom of the muffler. If you smoked the belt or got mud/water in the CVT housing, you would definitely notice some running problem. If the noise occurs when just revving the engine in Neutral, then that's not the CVT belt making the noise either.

 

no, i def. came from the rear part of the machine. I thought it something electrical actually, but dont know what would do such a thing...

Did also notice some type of plug back there...thinking my dealer installed my warn winch that may take a remote??? have to double check with themm....

Nothing with the belt. I have had that thing deep and never had issues...

 

brakes maybe? mine do it sometimes from wet muddy stuff....but are your back brakes discs?

 

Kawasaki has wet brakes. Its an oil sealed casing in the back that requires hardly any adjustment. They stay dry. Probably one of the best set ups out there.