popping from exhaust

[roost]

Ok, 1980 suzuki gs 750, carbs cleaned, valves adjusted, bench synched, runs and idles good.....except it has a lot of popping from the exhaust.

It this most likely from the rusted exhaust which has several large holes on both sides? Or the air screw is too rich? I have the air screw at 3 turns out.

I plan on swapping the exhaust for a stock suzuki exhaust that is in better shape later on.

Thanks, very helpful

[chef1366]

You have rust holes on the headers? That would cause popping for sure.

[roost]

No rust holes on the header, just the bottom of the exhaust, bigger than quarter sized holes on both..

[BassCliff]

Hi,

Having the "idle mixture screws" set too lean can cause popping on decceleration. Exhaust gasket leaks or air intake leaks can too.


Thank you for your indulgence,

BassCliff

[roost]

Popping is both acceleration and deceleration.. Fairly consistent, every 3-5 seconds.

[Dave8338]

What have you done to the bike as far as inspection / repairs ?

[Octain]

Popping on decel with a leaking exhaust is normal. But popping on acceleration is not.
If the holes are bad enough it might make the bike run lean.
That's not a good running bike as you mention, in my opinion.

When you say "carbs cleaned" what exactly does this mean? If you didn't completely disassemble and dip em per BassCliffs tutorial 1000% perfect, then I would start with this.

Who did the work on the bike, you or the previous owner? I've heard of many PO's who say the work was done but in reality all they did was squirt some carb cleaner in the carbs just enough to get the bike running.

[BassCliff]

Hi,

You should vacuum sync (balance) the carbs as well. All cylinders are not running eavenly.


Thank you for your indulgence,

BassCliff

[chef1366]

Cliff,
Don't put an "H" in front of your evenly.