Exhaust Change

[Mastermind]

Hi Guys

The 2006 Pitbull eventually arrived here in South Africa after a almost 3 month delay in the States. Services the bike and change the filters. The stock bike runs well.....a bit short on power though.

I was not happy with the standard exhaust so I made a free flow for the bike which the same was done on a friends 2008 Ridgeback.

The problem I need help with is that once the exhaust was fitted the sound after deceleration from the exhaust sounds flappy/splutters and backfires sometimes.

We checked the carb and made the settings identical on both (Standard jets in carbs) bikes. When my exhaust is fitted on the Ridgeback, it sounds perfect.When the Ridgebacks exhaust is fitted on the Pitbull, that terrible sound is still there.

We suspect that the timing on motor is not the same. Is there anyway we can get information on how to set the timing on the Pitbull or could somebody else maybe provide another solution to my problem.

Thanks

Gavin

 

[francoblay1]

You need a 585 cam & a Th programmable Ignition. (all Plug & Play, done in one afternoon!) :2thumbs:

1. http://www.bigdogbiker.com/forums/performance/52003-new-mods-success.html

2. http://www.bigdogbiker.com/forums/general/61510-i-am-back-road.html

3. http://www.bigdogbiker.com/forums/how/27075-585-cam-install-09-k9.html

4. http://www.bigdogbiker.com/forums/performance/8943-best-damn-upgrade.html

Let me know if you need more info. :up:

 

[francoblay1]

Also:

link: http://www.bigdogbiker.com/forums/fuel-air/14439-what-jets-do-you-run.html

 

[Tim]

Have you tried torque cones?

 

[Mastermind]

Hi Marco & Bubblehead, thanks for the input. I checked my jets and reset the idling which made a small change but the problem still persists.

I borrowed a friends service manual which made for some interesting reading. I may have found the problem but need confirmation from the experts on the forum. From the "Electrical "chapter, I noticed that there are 2 types of EHC's - The Smart Carburetted EHC (gold in colour) & The Smart EFI EHC (blue in colour). My 2006 Pitbull has a EFI EHC on it and my friend has the Carburetted EHC on his Mastiff. As the Pitbull uses a carb, then it should have the Smart Carburetted EHC, should it not? Could the incorrect EHC be the cause of the problem. If so, where can I buy the correct EHC?

Thanks again for all your help for this newbie.

Cheers

Gavin

 

[Brew]

Hello Master, The EHC that you're running should not cause the issue you are having. I was also running an EFI EHC on my carb bike when my original EHC crapped out and had no issues with it. You can run EFI EHCs on carbed bikes but you cant vise verse on the EFI bikes.

Have you pulled the spark plugs to see if you're running lean or rich? Let us know and pictures of the plugs would be helpful if you can.

 

[rhodes_96]

Hi Guys

The 2006 Pitbull eventually arrived here in South Africa after a almost 3 month delay in the States. Services the bike and change the filters. The stock bike runs well.....a bit short on power though.

I was not happy with the standard exhaust so I made a free flow for the bike which the same was done on a friends 2008 Ridgeback.

The problem I need help with is that once the exhaust was fitted the sound after deceleration from the exhaust sounds flappy/splutters and backfires sometimes.

We checked the carb and made the settings identical on both (Standard jets in carbs) bikes. When my exhaust is fitted on the Ridgeback, it sounds perfect.When the Ridgebacks exhaust is fitted on the Pitbull, that terrible sound is still there.

We suspect that the timing on motor is not the same. Is there anyway we can get information on how to set the timing on the Pitbull or could somebody else maybe provide another solution to my problem.

Thanks

Gavin

Have you checked your intake for leaks ?
What fuel are you using ?
Not all BDM 117 motors are the same. There are some with intake restrictions, different cams, different rocker box configurations, California models with pollution control setups, etc.
Each setup needs to be adjusted for the individual bike !
Dialing in the same setting from one bike to the next is not the way to do things.


For me I run my bigdog 1/8 turn clockwise on the idle mixture than the base setting after adjusting the carb, this fixed my decel popping until I change the jets. My friend has same exhaust on his bigdog, and had to do nothing after adjusting the carb from basic settings.

 

[liferider]

I had the same problem on the flappy backfiring when letting off throttle when I went from V&H shotguns to the Martin Brother Mudusas. Go find a Dyno!

 

[demon dog]

did you put new exhaust gaskets on? I switched to the tapered exhaust gaskets and it eliminated my decel pop