Decel popping/ backfiring

Energy One
wbruiser2

wbruiser2

Member
After reading numerous threads on carb adjustments and decel popping, etc... I have an issue I just wanted to run by the more experienced here.
As in my introduction, I just got an 05' ridgeback. I knew when I got it, it was running rich because of black smoke and severely fouled plugs. When I pulled them they were black and I could knock the build up off with a wire brush. The air filter was just nasty. So, I replaced the plugs with autolites and the air filter with a K&N. I made the carb adjustments as per the S&S manual. And I changed the oil.
I took it for a ride yesterday and the decel popping and backfiring was, well, it was kind of embarrassing. It was extreme, not cool. But it ran like a raped ape otherwise, no hesitation, hiccups, or anything. In my experience, this has been 90% of the time, been a exhaust leak issue. I checked the manifold bolts and maybe a got a turn to a turn and half on a couple of them. The intake was good. I pulled the plugs and it appears I'm to lean now. They were almost silver on top. But if I richen it up, black smoke comes out when you hit the throttle a little when sitting still.
The carb has been re-jetted (what sizes I don't know but I'm sure they're right due to the otherwise excellent performance) and a mean mothers exhaust with baffles are on it.
Any suggestions? Opinions?:confused:
 
Raywood

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Hard to tell. But the pipes are long enough so you should be able to tune it in pretty good. If you've verified no intake leak and you've adjusted the carb like you should then I would look at the exhaust again.

I've had that popping before and eliminated it by doubling up on the exhaust gaskets. Sometimes these custom pipes we have will have longer flange collars and you don't get the tight seating you should resulting in a leak.

I don't use the angle shaped crush gaskets. I use the standard flat ring gaskets but double them up and that seems to take care of it for me.

Something to look at.

:cheers:
 
wbruiser2

wbruiser2

Member
Thanks for the advice. I think I will ride toward a bike shop today to get some gaskets and while on my way see if I can tune it in some more. If it isn't any better by the time I get there, I will get the gaskets. Your suggestion makes sense and explains a lot. Thanks again.
 
lee

lee

Well-Known Member
when you say you "richen it up" I assume you are doing this by adjusting the idle mixture screw (because you say you don't know what jets are in it). This is probably why you are getting black smoke, or your accelerator pump is too far out. IF you are running lean increase your intemediate jet and readjust the idle mixture screw and accelerator pump. The idle mixture screw only really affects the A/F mixture when your throttle is closed.
 
W

waykool

Banned
Mine hesitates on acceleration and pops on deceleration. I’ve had it adjusted and re jetted by professionals at a local BDM shop and now is even worse. I just live with it. Seems to be the nature of the beast. Good luck man.
 
LDO

LDO

The Cleaner
Troop Supporter
if you are 100% certain you don't have an intake leak, check for an exhaust leak. I had one and it was hard to see/find. Once I removed the exhaust for other stuff, I found it.

Now, no popping nothing but a strong pull all the way thru the gears. I'm loving it....
 
wbruiser2

wbruiser2

Member
Well after riding about 80 miles today with my trusty flat tip screw driver, all is well. It just needed to be a little richer... just like me... I think I turned it out about a turn and 1/4 when it was all said and done (from the initial setting). It will backfire/ pop a little every now and then but it's the "cool" kind. I hardly even notice it unless the rpms are high when i'm down shifting:whoop: .. Thanks to you all..
 
Dead Stroke

Dead Stroke

Mark
LDO
I have this popping on decel as well and sometimes a backfire when I hit the starter button. What do you recomend. How do you check for intake leaks? I do have the S&S carb instructions for the adjustment that I can try.

I will say the motor runs strong. absolutley no hesitation anywhere.
 
W

woodbutcher

Mr. Old Fart member #145
Staff member
Dead Stroke said:
LDO
I have this popping on decel as well and sometimes a backfire when I hit the starter button. What do you recomend. How do you check for intake leaks? I do have the S&S carb instructions for the adjustment that I can try.

I will say the motor runs strong. absolutley no hesitation anywhere.
Click to expand...
if it is popping on decel, try tightening up the exhaust bolts. they tend to work loose often so it is a good idea to put jam-nuts on them also. as far as the carb adjusting goes, try here- http://www.bigdogbiker.com/forums/how/4943-how-adjust-your-carb-check-jetting.html. :cheers:
 
lee

lee

Well-Known Member
and to check for intake leaks spray some brake cleaner to where the intake manifold joins the heads whilst the bike is idling. If idle speeds up momentarily you have an intake leak.
 
LDO

LDO

The Cleaner
Troop Supporter
Dead Stroke said:
LDO
I have this popping on decel as well and sometimes a backfire when I hit the starter button. What do you recomend. How do you check for intake leaks? I do have the S&S carb instructions for the adjustment that I can try.

I will say the motor runs strong. absolutley no hesitation anywhere.
Click to expand...
Mark,
Wood and Lee got it covered. All I can add would be to check out Ray's thread on exhuast where he mentions going to the old style (screamin eagle) exhaust gaskets (doubled). I did and I've got a pretty good seal on my pipes now....

Here's the thread:
http://www.bigdogbiker.com/forums/general/11364-exhaust-gaskets.html
 
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