Rubber Belt / Bird Squeaking Noise From Exhaust

Carlotto Posts : 27 Join date : 2020-05-23

I haven't noticed it before but after I balanced the TBs I have what sounds like a loose rubber belt noise / small bird squeaking from the exhaust

It's noticeable from idle and particularly if I blip the throttle

As the only belt is on the alternator and that's at the front and this noise seems to be from the exhaust I'm wondering if balancing the TBs could create a resonance or something ?

I haven't looked at the Alt belt yet but the noise isn't coming from the front

GRiSO Capo Posts : 7752 Join date : 2013-09-30

Possibly something resonating. What pipe? If it's a Termi, that's highly likely.

Carlotto Posts : 27 Join date : 2020-05-23

It's a Scorpion - straight through, no baffle

I'll try adjusting the TB air screw slightly and see what happens

GRiSO Capo Posts : 7752 Join date : 2013-09-30

Yeah, I awoke in the wee hours and cried out "it's not a Termi".

Please excuse my bad memory. I can barely remember what I did yesterday.

Grignapoco Posts : 148 Join date : 2016-09-09

Big singles and twins occasionally have a chirping exhaust sound. Never bothered to investigate but could be a very slight air leak or part of the international baffle tube resonating. My time spent owning/ riding Guzzi twins is far to brief to claim that I have noticed this characteristic on GRiSO’s etc.
Put a rolled up cloth over the exhaust outlet to mute the sound and possibly help identify the source.

GRiSO Capo Posts : 7406 Join date : 2013-05-29 Age : 63

Cracked pretzel?