decel popping and plug gap?
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Road Captain
Joined: Jul 2006
Posts: 667
Likes: 8
From:
RE: decel popping and plug gap?
Glad to see this post has created so much interest/comments. Im no wrench, by any means, but I wanted to share my experience in the hope it helped someone else. Ive no clue why it worked in my situation...and DO plan to go ahead and purchase some type DFO or TFI in the event I change pipes....that seems to be the most popular thing here as far as minor mods are concerned.
Anyway, just glad to see it created interest or thought. BTW, I was at my dealer this morning to get a new tank panel.....yeah, still buying more all the time like everybody else......and the tech there is still saying that everything else on my dyno run looked great.
Goodluck to anyone else with this issue.
Anyway, just glad to see it created interest or thought. BTW, I was at my dealer this morning to get a new tank panel.....yeah, still buying more all the time like everybody else......and the tech there is still saying that everything else on my dyno run looked great.
Goodluck to anyone else with this issue.
Cruiser
Joined: Jun 2006
Posts: 163
Likes: 0
From:
RE: decel popping and plug gap?
Checked the gaps toady and they were within spec. But, the plugs were very slightly covered with black right at the first 2 threads-not wet at all but sooty black (which I easily removed).
Pretty sure I was running a tad to rich at mid and high range RPM so I leaned it up a bit there.
Pretty sure its set pefectly for low RPM.
Pretty sure I was running a tad to rich at mid and high range RPM so I leaned it up a bit there.
Pretty sure its set pefectly for low RPM.
Road Master
Joined: Mar 2005
Posts: 878
Likes: 0
From: Cistern,Tx
RE: decel popping and plug gap?
ORIGINAL: lschultz
Last week I was talking to George at Dobeck Perf. I have a DFO on and had it setup where it was running great, getting good mpg, no popping. I put Fullsac true dual pipe on and now it started popping on decel. Talked to George and I think the first thing he asked me about was if the plugs were gapped right. I did the 10000 on it and had put new plugs in. DUH it did not dawn on me when he asked me that. He told me some settings to try and it has improved the popping but not elimanted it so I am getting off my **** and go check the gap on the plugs.
Last week I was talking to George at Dobeck Perf. I have a DFO on and had it setup where it was running great, getting good mpg, no popping. I put Fullsac true dual pipe on and now it started popping on decel. Talked to George and I think the first thing he asked me about was if the plugs were gapped right. I did the 10000 on it and had put new plugs in. DUH it did not dawn on me when he asked me that. He told me some settings to try and it has improved the popping but not elimanted it so I am getting off my **** and go check the gap on the plugs.
4th Gear
Joined: Sep 2006
Posts: 8
Likes: 0
From:
RE: decel popping and plug gap?
Seems people can understand that if you widen the gaps the pop problem is solved, but
can't understand they are altering the system by that.
That's also not curing the problem on it's base, actually the pops are normal...!
To sorten this out I gave my machine for a electronic checkup to see flow is right and
let them check the gaps and color of the plugs.
(I also have screaming eagles and a KN airfilter installed and have heavy pops on decel.)
All was perfect.
I talked to mechanics of 2 different authorized dealers and this is what they both told me,
one after the check-up and road test by himself:
If you have screaming eagle's or other custom exhaust then it's TOTLAY NORMAL you have
pops on deceleration (lower speeds) because it's a totaly different exhaust.
(If you have original exhausts and have a pop on decel, that's another story...)
They both STRONGLY adviced NOT to widen the gaps to stop the popping, especially on fuel injection
types, the ECI after all checks constantly what's needed and gives the right flow of fuel and air.
So if you widen the gaps you are actually altering the setup and this should not be done.
So in my opinion, after what I have heard from different mechanics I would leave the gaps
at the standard setting. However, it's a good thing to check the spark plugs to see if they have
a good color and are having BOTH the same gap distance!
If I would be sure to solve the pops with widening the gaps and the mechanics would say it
doesn't harm, I would do it riight away, I rather have them not!
So if you can't live with the pops, mount the original exhaust
Regards, Pierre
can't understand they are altering the system by that.
That's also not curing the problem on it's base, actually the pops are normal...!
To sorten this out I gave my machine for a electronic checkup to see flow is right and
let them check the gaps and color of the plugs.
(I also have screaming eagles and a KN airfilter installed and have heavy pops on decel.)
All was perfect.
I talked to mechanics of 2 different authorized dealers and this is what they both told me,
one after the check-up and road test by himself:
If you have screaming eagle's or other custom exhaust then it's TOTLAY NORMAL you have
pops on deceleration (lower speeds) because it's a totaly different exhaust.
(If you have original exhausts and have a pop on decel, that's another story...)
They both STRONGLY adviced NOT to widen the gaps to stop the popping, especially on fuel injection
types, the ECI after all checks constantly what's needed and gives the right flow of fuel and air.
So if you widen the gaps you are actually altering the setup and this should not be done.
So in my opinion, after what I have heard from different mechanics I would leave the gaps
at the standard setting. However, it's a good thing to check the spark plugs to see if they have
a good color and are having BOTH the same gap distance!
If I would be sure to solve the pops with widening the gaps and the mechanics would say it
doesn't harm, I would do it riight away, I rather have them not!
So if you can't live with the pops, mount the original exhaust
Regards, Pierre
Road Master
Joined: Mar 2005
Posts: 878
Likes: 0
From: Cistern,Tx
RE: decel popping and plug gap?
I here what you are saying. HD spec on mine is .038-.043 so as of now I have them set on the high side at .043 in spec and it took 99% of the pops out. I will keep checking the plugs. Not knocking your mechanics over there but if they are like some of the ones they have over here it makes you wonder.
4th Gear
Joined: Sep 2006
Posts: 8
Likes: 0
From:
RE: decel popping and plug gap?
Ok, since I want to sorten this out I am gonna check several configurations and post them here.
First I installed the original mufflers which I didn't hear because I'm almost deaf from the Screaming Eagles
The sound is like riding on a big scooter so I don't like it...
I love the sound of the SE's but they are a bit to load (maybe I'm getting old)
The guy from the shop said you can perforate the originals with a large
iron bar which will sound then louder but not to loud.
Since I have the originals and there is a chance we have to go to inspection every year
in near future to check if the bike is ok for traffic I rather don't, so I still have original ones...to go to the inspection
The pops where totaly gone, so it's definatly because the SE's are actualy...a hole...lol
Mounted the SE's back on and then take a go to alter the gaps of the sparks.
Standard they were 1 mm (0.038 inch I guess) and max. standard should be 0.045inch so I calculated
I could open them to 1.10 mm at max which I did.
Took a testdrive and yes, the pops are much less, but still a few in the low area.
I will test tomorrow with 1.20 mm and 0.9 to see what difference it makes.
If not good I set them at 1.10 back again.
Regards, Pierre
First I installed the original mufflers which I didn't hear because I'm almost deaf from the Screaming Eagles
The sound is like riding on a big scooter so I don't like it...
I love the sound of the SE's but they are a bit to load (maybe I'm getting old)
The guy from the shop said you can perforate the originals with a large
iron bar which will sound then louder but not to loud.
Since I have the originals and there is a chance we have to go to inspection every year
in near future to check if the bike is ok for traffic I rather don't, so I still have original ones...to go to the inspection
The pops where totaly gone, so it's definatly because the SE's are actualy...a hole...lol
Mounted the SE's back on and then take a go to alter the gaps of the sparks.
Standard they were 1 mm (0.038 inch I guess) and max. standard should be 0.045inch so I calculated
I could open them to 1.10 mm at max which I did.
Took a testdrive and yes, the pops are much less, but still a few in the low area.
I will test tomorrow with 1.20 mm and 0.9 to see what difference it makes.
If not good I set them at 1.10 back again.
Regards, Pierre
4th Gear
Joined: Sep 2006
Posts: 8
Likes: 0
From:
RE: decel popping and plug gap?
0.9mm and 1.20mm was not sparking well, it seems only
the standard 1mm (0.039 inch) gives the most plops and 1.10 (0.043inch)
is the better setting.
I leave it to this and watch it closely.
the standard 1mm (0.039 inch) gives the most plops and 1.10 (0.043inch)
is the better setting.
I leave it to this and watch it closely.
Outstanding HDF Member
Joined: Oct 2006
Posts: 2,340
Likes: 2
From: Omaha Nebraska
RE: decel popping and plug gap?
ORIGINAL: nickpipe
Well here are my 2 cents worth on the plug gap. If your plugs are under gapped the ignition wont build the right amount of voltage to fully fire and burn the fuel in the cylinder. The closer gap requires less voltage for the spark to jump the air gap. When your plugs are gapped correctly the coils have to build a higher voltage charge to jump the air gap resulting in a hotter spark thereby burning the fuel better in the cylinder. The pop in your pipes on decel is caused by raw fuel being dumped into your pipes and ignighting from the heat of the pipes.
Just one man's opinion, Are there any Guru's that can shed more light on this
Nick
Well here are my 2 cents worth on the plug gap. If your plugs are under gapped the ignition wont build the right amount of voltage to fully fire and burn the fuel in the cylinder. The closer gap requires less voltage for the spark to jump the air gap. When your plugs are gapped correctly the coils have to build a higher voltage charge to jump the air gap resulting in a hotter spark thereby burning the fuel better in the cylinder. The pop in your pipes on decel is caused by raw fuel being dumped into your pipes and ignighting from the heat of the pipes.
Just one man's opinion, Are there any Guru's that can shed more light on this
Nick
I was going to say about the same thing ......just not as many words.......Hotter spark
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