Exhaust Chirp

[Donvito]

My bike has been making a chirp sound from the exhaust for a while. Now that I have my more serious problems under control, I would like to know what it is. I am attaching a recording so if anyone can offer some advice I would appreciate it.

 

Thanks.

Edited June 2, 2013 by Donvito

[friesman]

to me, it sounds a lot like the sound my 85 had when the baffle in the exhaust collector shook loose. A friend and I laid the bike over cut a trap door in the collector, took the loost baffle out and welded the collector back up and then welded a steel plate over that to ensure it would hold up.

 

brian

[jimmyenglish]

That doesn't sound like the baffle to me. I had the baffle prob and it's much more of a rattle. That sounds like a backfire to me. My 86' backfires just like that at idle but it's not so much a chirping sound. More of a burp throug the carb(which I don't know which one, it's done it since I've owned the bike). The baffle woe is a lot more annoying than that.

[steve crossley]

sounds like 1 carb is way out of sync try a sync job and see if it goes away .

[Peder_y2k]

That sound is definately a fuel mix related issue, where a small amount of unburned fuel is passing into the exhaust from either a rich or lean condition causing a misfire. Try adding Seafoam or Techron or Chemtool B12 to the fuel tank. If no improvement in 30 miles, you might try adjusting the pilot screws (idle fuel misture), if no improvement then proceed to carb synch.

If it were my bike that has a fuel conditioner regimen already, I'd start with the pilot screws.

-Pete, in Tacoma WA USA

'83,88

[Donvito]

Carbs are synced. I recently did the carb cleaner soak and that really helped. It is running great except for the annoying chirp. So, I think I will start with the fuel mixture adjustment. Would you guess the mixture is too rich or too lean?

[Trader]

pull your plugs and take a look.

Better than guessing which way to adjust.

 

should be a gray color. If they are black you are rich....if they are very light grey to white, you are too lean.

 

I'd check for vacuum leaks too. Spray a little either or open a propane torch ( unlit!) in and around the carb boots. If the idle jumps at all you have a vacuum leak.

[MasterGuns]

Carbs are synced. I recently did the carb cleaner soak and that really helped. It is running great except for the annoying chirp. So, I think I will start with the fuel mixture adjustment. Would you guess the mixture is too rich or too lean?

 

 

My guess would be too rich. Mine was doing the same thing and someone on here recommended starting off with a 1/8 lean turn (CCW) on each of the fuel mixture screws. Made short order of the problem or burping sound. Reminded me of a Sergeant Major I once knew after he had a few too many.

[Donvito]

My guess would be too rich. Mine was doing the same thing and someone on here recommended starting off with a 1/8 lean turn (CCW) on each of the fuel mixture screws. Made short order of the problem or burping sound. Reminded me of a Sergeant Major I once knew after he had a few too many.

 

Thanks for the advice. Is it ccw to lean it? I thought it was cw to lean. I've been adjusting under the premise that unscrewing it made it richer. Could be where I messed up.

[Peder_y2k]

CW (turning 'in') leans the mix, turning out (CCW) richens. The pilot screw controls a mix of air plus fuel, not just air OR fuel, but both.

-Pete, in Tacoma WA USA

'83,88