Topic: 550 popping

[Brandotheamazing]

bike was synced and carbs jetted when running pods, currently running a stock air box. baffle was rusted to pieces and i took it out, cut at the end and left the end of the baffle in there. It back fires on decel pretty bad now. lot's o popping and what not. what should i try?

[trueblue]

is it popping through the exhaust or backfiring through the carbs

[Frostyboy]

I'd have to suggest putting baffle/s back in, or a replacement muffler first.
Then have a think about checking what jetting is in those carbs & consider putting them back to stock if they're way off.

[Roach]

noticed mine doing it aswell I cut my baffle off half way . has to do with back pressure.

[dave500]

thats a lean idle and off idle circuit,you might adjust it out with the screws but i dont think you will if its bad,what exhaust do you have?if its a non baffled straight through youll get popping aswell with close to lean slow jetting,combination of both,id fix the exhaust first and see what it does.

[bwaller]

Check for good seal of the pipes at the head, an air leak there will lead what you describe, mostly on deceleration.

Replace the exhaust seals.

[domer]

i would say you are running rich. carbs tuned for pods are gonna be richer, and popping from exhaust is one sign. id swap the jets. the baffle might have something to do with it, but id suspect the switching of filtration systems first...

[Trav-i]

My 750 bobber sort of pops or burbles on decel too.  It's stock jetting with stock airbox, but I have a custom made exhaust on it which is a 4-2 glasspack design.  It talks to me evertime I let off nothing to loud, just grumbles along which is normal on such a free flowing system. 

The best compliments I've ever gotten on the bike are from the people who have ridden behind me at high RPMs they love that sound.

Plus, if your back on a stock air box, you def need to check that jetting.  Probably running a bit rich.

Travis

[trueblue]

is it popping through the exhaust or backfiring through the carbs

The reason why I asked this question is as a general rule of thumb, if it is backfiring through the carbs it is more than likely running lean, where as if it is popping out the exhaust it is running too rich, there are exceptions to this rule though.  A lack of backpressure will also cause popping in the exhaust, I have heard them in this instance sounding like a 12ga going off when you back off.

[bender01]

Check for good seal of the pipes at the head, an air leak there will lead what you describe, mostly on deceleration.

Replace the exhaust seals.

+1 It happened to me butching a mac 4>2 rust job. I replaced the crush rings and reseated the headers and much quieter.

[dave500]

retarded ignition will also cause it,retarded ignition can cause back firing through the carbs on accelleration,pop,pop,pop on decell on an otherwise in tune engine points to a lean idle circuit.

[Brandotheamazing]

hey, it's popping thru the exhuast, i dont realy remember if it did it before the baffle came out. i'll fool with the carbs, and check the jetting when it stops being so rainy out.