Popping sound????

[gilbert7878]

I already have my first problem with my bull dog. If anyone knows what is causing this would be a great help.
When I let up off the gas I hear a popping sound almost like a back fire when I'm riding. My brother thinks it might me an intake leak but we are not a 100% sure. If I keep my RPM's low it dosnt do it, only if its around 3000 or higher RPM's. The motor is a 107 and it only has 2500 miles on it and the bike is an 04.
Any ideas???
Thanks
G

 

[kirk927]

This is a long documented issue with these motors. You can do a search and see. The way to fix is long and numerous but try simple carb adjustments first. I have the V&H BR's and I adjusted my carb and it no longer pops. I hope this answers your question.

 

[TLB08K9]

There was a post a while back explaining decel pop.

http://www.bigdogbiker.com/forums/technical/6516-exhaust-popping-decelartion.html

 

[gilbert7878]

Thanks you guys. So basicly this is fine?

 

[TLB08K9]

I am no expert but mine pops pretty much at any rpm at decel, the guys that dyno'd my bike and reading threads on here it is pretty much normal without baffles or even chopped baffles. If it start on accel. then you could have a leak somewhere. My :zz2cents:

 

[gilbert7878]

The thing that a little bit of a concern is that I still have the origenal pipes on it and most of the guys on here have said its happend after they put differant pipes on their bike.

 

[TLB08K9]

mine popped 500 miles after getting the bike (2700 now), had the baffles done around 900 and all it did was make the pop louder. did gain 10 hp by just drilling baffles and high flow air filter, so i just deal with the louder pop, till the pipes turn a little more and then gonna purchase another set

 

[HDLARRY]

In my experiance decel popping is normally caused by not enough back pressure in your exhaust system. Low or no back pressure can be caused by exhaust leaks around joints or at header connections. Also little or no baffle's will cause this.

With stock exhaust your baffles should have plenty of back pressure. Check the exhaust flang nuts first.

 

[Daddycool]

I had the same thing and I just adjusted my carb and it quit.

 

[lee]

I'm with Larry

A bit of popping is actually a good thing but if yours have recently developed and got real bad I would check the exhaust nuts - my bike started popping really bad, even when letting off the shift and when I got home I noticed one of my nuts (exhaust nuts boys!) was missing.

 

[gilbert7878]

I'm going to a bike night tonight so I'll talk with a few guys there and also see if I hear any of there bike doing it when they come in.

 

[P8RIOT]

...I noticed one of my nuts (exhaust nuts boys!) was missing.

Thanks for clarifying - thought that might be some sorta British humor going on there!

 

[BBChopper]

I'm with Larry

A bit of popping is actually a good thing but if yours have recently developed and got real bad I would check the exhaust nuts - my bike started popping really bad, even when letting off the shift and when I got home I noticed one of my nuts (exhaust nuts boys!) was missing.

Man I hate it when that happens!!!!
:roll: :roll:

 

[gilbert7878]

So I was talking this over with one of my coworkers today and he thinks it might me by jetting sense i bought the bike in Cali and I'm in AZ. My other bike is fuel injected so I dont know that much about jetting. Do you guys know of any good websites that talk about jetting?

 

[lee]

Do you guys know of any good websites that talk about jetting?

yes - this one!

do a search - it has been extremely well covered. You might need to up your jet sizes

 

[lee]

Thanks for clarifying - thought that might be some sorta British humor going on there!

and I still had 3 nuts left

 

[Gas Man]

Sounds like you need to double your nut Lee

 

[lee]

I am going to do that when I get my bike back - if I ever get my bike back

 

[Cutter]

You obviously need to get you jets right, if they aren't already.

I also notice that if I tweak my idle mixture after the bike is completely warmed up, about 1/4 - 1/2 turn depending on the temp and humidity, it will take care of the decel pop...
afterwards, I typically only get it if I decel on a steep decline...

 

[gilbert7878]

So I looked up the elevation of where I bought the bike which is 350 feet and Tucson is 2300 feet. I called a few shops today to see if I can get some new jets for my carb but no one new what size I need. I would have thought these peopel would be doing this stuff all the time but I guess not. Does anyone on here know what size jets I would need for 2300 feet?
Thanks G