I recently bought a 2007 1200c used with 4000 miles and in the first 1000 miles I didn’t notice any problems. At 5000 miles I changed the oil and replace the air filter with a new factory filter and have since noticed some backfiring and when sitting it smells like it is running rich. It also feels like its jerky at low speeds unless I am really on the throttle or that could just be me being used to riding sport bikes.
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The pipes appear to be cheap knockoffs because I can’t find a brand name anywhere. I attached a pic of the pipes. Nothing else mechanical has been changed. I just pulled the plugs and they looked relatively clean with very little build up.

Any ideas on what is causing the backfire on deceleration and the occasional burp while idling?

I could just be noticing it now more than before.

Thanks for the help.

 

Does anyone know what kind of pipes they are? The only thing I could find that looks like the or V&H twin slash slip ons with the baffles removed which is probably causing the backfire.

 

Anyone?

 

So the thing is running just fine up until you changed the oil and filter? I would start there. The oil is not going to cause it to run rich or backfire so it pretty much has to be the filter. Try re-installing the old filter and see what happens. If that doesn't work then go with another brand filter. No other carb settings were fooled with...right?

Vance and Hines pipes are all clearly marked so.

 

That's a real good possibility. The stock bike is lean from the factory to begin with, and the loss of back pressure by removing the baffels will only make it worse.

All I can say to that is, HUH??? Can you give us a technical explanation of how that is possible?

 

I would try a new filter but I threw the old one away and it was also a factory filter.

It's FI so now carb setting were messed with.

I'm starting to think its just the lack a back pressure causing the popping but it still doesn't explain the occasional miss while idling.

I've never owned a HD before just sport bikes but on most of them with just a pipe change and no intake change a PC with a remap was never needed. Is this different on HD's?

 

Makes sense and would explain why the plugs are still clean and not fouled. I just don't understand why the change with the new air filter.

 

It's just a possibility, but if the old filter was clogged and restricting the air flow, that would create a slightly richer mixture. A clean new filter with better flow would cause a leaner mixture and as a result the pops on decel.

Note: I was assuming above, that the poster was referring to your oil filter (as part of the oil change) and not the air filter. If that was the case, it would make sense.

 

The issue is that the OP said that the backfiring began AFTER changing the oil and air filter. So that really rules out the "lack of back pressure" from the pipes since those were already there with no problems. I don't see the pipes as the problem. Maybe an O2 sensor went dead. Or you have a connection problem with one, or both, O2 sensors.

 

Anyone have an idea what kind pipes they are?

The new cleaner and less restrictive filter sounds like it might be it.