The exhaust gets a lot hotter when it's running lean. Those extra hot pipes will ignite the unburned gas while those of a cooler running motor will not.

 

That's good!

 

Do you have the xied or the vied? If you have the xied's you cannot adjust them as they are preset. The vied's can be adjusted.I have the fl-vied-10 which I ended up adjusting all the way clockwise and only get a small pop when I get the rpm's up high then roll of the throttle. Someone mentioned earlier that you can never get rid of decel pop completely. That may be true with xied's or vied's but with a good tuner and some dyno time it can be done. my other bike is a 09' nightster that I put v&h shortshots and a big sucker a/c on. I had a shop put in the sert and had it dyno tuned and get absolutly no decel pop whatsoever. She runs great too. Before I went with the sert and dyno I had the pcIII and could not get rid of the popping. With my heritage I'm saving up my cash now to go with the thundermax with autotune,rinehart 2 into 1 and a stage one a/c from fuel moto.

 

I've got my FL-Vied-10's running at about 60%. This morning the second day of riding with them installed it seems like the pop has gotten less/better. I'll give it a few more rides and then maybe turn it up some more if not completely gone.

 

Decel popping...some like it, others don't.

Decel popping does Not damage your engine...it is simply unburnt fuel that is burning in the exhaust tract after exiting the engine.

Decel popping occurs when one of two things are present.

1. The bike is so lean the exhaust is superheated and is burning the unburnt fuel that is in the pipes (there is always some unburnt fuel in the pipes no matter how lean). This is very rare, and does not occur with the stock map and free flowing pipes being the only change.

2. The AFR IN THE pipes is just right to burn the unburnt fuel. This is quite a common occurrence when free flowing pipes are installed (whether or not a free flow A/C is installed). It can also occur if there is an exhaust leak that is introducing extra air into the exhaust tract.

To get rid of decel popping a lot of people put MORE fuel than is needed into the engine/over-richening the AFR so that more unburnt fuel goes into exhaust, changing the AFR in the exhaust so that is no longer optimum for combustion in the pipes. This is just a waste of gas. And if using decel enleanment found on most tuners it is still really hard to get rid of the popping/burbling when the injectors kick back in at about 1750 rpm.

Another way to get rid of decel popping is to change the AFR in the pipes (mufflers/Slip-ons). This can be done with different baffles, a lolipop or Thunder Torque Inserts. The benefit to the TTI's is that it will let you keep your sound, increase the low and mid range power, and reduce/eliminate the decel pop by reducing/eliminating reversion, thus changing the AFR (in the pipes) to one that is not conducive to combustion.

 

I heard it the other way. if the mixture is richer, there's more unburned gas available to pop on decal. dunno.

put a pc 5 in my '09 'bones ... the factory f/a ration is not optimum. its leaner to meet pollution requirements. I tweeked the pc5 to make it a bit richer and reduce combustion temp (better for the metallurgy). and got a bit if popping. I like it.

 

5 entire pages of conflicting advice. Awesome.

I've come to the conclusion that the only way to properly tune these EFI bikes now is a dyno.

 

Sure wish you guys would figure this out, I don't want to be a ginni pig.

It's not that I mind the popping, I just don't like the coughing.

I'm stunned by the dealer response to this issue, brand new bike and they want everyone to by a $500. mapping key to make the bike run correctly.

 

Very true!

 

I've learned to live with mine. I might get the hop to look at it when I do my 10k service and see what they say.