Deceleration

Scotty k

Scotty k

New Member
I read somewhere on the site, a guy has his bike running so good it has no POP on deceleration. Is that possible ? I have never ridden with other Dogs so I have nothing to go by other than my 2006 Pitbull. Big diameter short pipes,( mean mother's)and super G carb. My pipes have what I would call excessive bluing (excess fuel burning in pipes ? ). I would guess that its running rich but the plugs are a nice brown color. Do I have room to lean it out? or is it just the short exhaust and no back pressure ?

Opinions?
 
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scgorazd

Member
I had a similar problem on my 09 k9. My setup is a s&s dual runner air intake and a V&H 2 into 1 big radius pipe.

I had some wicked nasty deacceleration pop, to the point of where whenever I would roll off of the throttle it would start to pop off the unburned fuel. It got to the point to where I would pull the clutch in as soon as I let off of the throttle.

I did 2 things, which seemed to eliminate the deaccel pop of unburned fuel by 95%.

1. I put a different baffle in my 2-1 exhaust from big city thunder
2. I installed a more aggressive cam (from stock 569 to a 585 if I remember correctly)

Where I really noticed the difference was the cam (installed at a later date from the baffle, so I was able to isolate what reduced the deacc pop the most). I did not install the cam for this purpose, it was just a very pleasant surprise.

It's entirely up to you, but from my experience a cam has made a world of difference, for only a couple hundred bucks (if you install it yourself). Not to mention the power gains.
 
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Sven

Well-Known Member
1. Rich running on lift is a vacuum draw of more fuel entering than say air. So there is this ratio change on lift as opposed to open throttle. Rich snuffs out the pop. But at what performance drop to those brown plugs.

2. I have to ask myself, Intake? Are you crisp feeling? Are you easy to start and idle? Is your WOT clean from idle up to that opening? Yes. Then, what are my options?

3. I suck in the same signal only faster with a cam. I open [longer] and close [faster] as opposed to stock. So for argument sake, no carb change, I what? I suck air faster than the fuel moves? So I lean out, yes? Did I change jetting with cam? See how that could go 2 ways? Lean is less unspent to pop. Rich is wash the pop. Did or did we not, scg, leave the jetting alone?

4. On the intake side, the bike runs tits. On the exhaust side it takes, "Man Ears" to ignore a pop.
 
mittens

mittens

Well-Known Member
Mine pops on Dcell alot. and shots blue flames out at night.

Orange shortys when on it hard at night, and then blue/ white one swhen shifting ha.
 
Scotty k

Scotty k

New Member
I do know from my motocross days, a brown colored plug means correct air/fuel mixture. I too dig the night time flamage from the big radius short LOUD pipes. As far as the "POP"... I'm an equipment operator, I'm half deaf anyway. Besides...chicks dig it. So it sounds like a little decel pop is acceptable performance. I will keep the bluing polished off the chrome.

:2thumbs:
 
The Honch

The Honch

Active Member
I've got a lil pop on mine and I kinda like it. Definitely not something I'm going to try and eliminate unless it gets out of hand.
 
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