Much popping/backfiing

roadhawg · 02-21-2018, 12:09 PM

My Nomad runs like a “scalded dog” but when I let off throttle a lotta popping and backfire! Should I be concerned or should I just ride it like I stole it?

redjay · 02-21-2018, 12:42 PM

It appears you have V&H pipes ?
Is the rear header pipe cracked ?

cbutoday · 02-21-2018, 01:35 PM

Sounds like an exhaust leak!

DragonLady58 · 02-21-2018, 02:10 PM

Weeeeeeell, air being sucked into the hot exhaust is causing the problem, whether it be a leaking exhaust gasket, a crack in the rear pipe. The Old hoses that hook up to the reed valves and/or the reed valves themselves can also cause this....
Another idea, if all this checks out, and no problems found, a over rich mix in the FI or carb system, either by the carb being outta adjustment, or the FI system running a tuner....if the engine is running, some unburned gas enters the super hot exhaust, when you roll off throttle, you can get into popping, too.
I've seen people with coasters involved, that they didn't clean the mounting/sealing surface enough, causing a air leak.
Theres a leak somewhere thou.

**ringadingh** · 02-21-2018, 08:27 PM

If you have Vance & Hines pipes, I'd bet that the rear pipe is cracked at the first bend.

ldhthept · 02-21-2018, 08:53 PM

If pipe was cracked enough to cause popping he would prob be losing power and not run like a scalded dog. Just my 2 cents...

roadhawg · 02-22-2018, 09:42 AM

Yes i have had cracked VH pipe and had it welded both times . last time they put 6 inch metal sleeve into weld and so far so good, but again i will check for leakage, thanks to all for your input!

redjay · 02-22-2018, 11:01 AM

Are the acorn nuts on the exhaust flanges at the heads good and tight ?
Sometimes they can bottom out and although they appear tight they are not.
A washer or two under the nut cures that issue.

duo1983 · 04-12-2018, 05:22 PM

When that happened to me I found that I had a broken piston and had to have a top end rebuild done

roadhawg · 04-14-2018, 03:18 PM

I found a small hose that came off and put it back on and no more popping! Seems to run better too

mrtelefoneman1 · 04-14-2018, 07:49 PM

Out of curiosity, where was this small hose located?

roadhawg · 04-15-2018, 08:14 PM

On backside of engine about halfway up, small tube that small hose goes on

02-21-2018, 12:09 PM	#1
roadhawg Advanced Member Join Date: Feb 2012 Location: Starke Florida Posts: 856	Much popping/backfiing My Nomad runs like a “scalded dog” but when I let off throttle a lotta popping and backfire! Should I be concerned or should I just ride it like I stole it? __________________ "Ride it like you stole it"! 2008 1600 Nomad 56K miles "BlueBelle" 2004 1500 Nomad 102 K miles "Black Beauty" ABATE Black Creek Chapter Amvet Rider Post 86 http://www.facebook.com/AmvetPost86 Weston A. Price Foundation member. Vegetarian...... An old Indian word meaning "Bad Hunter" Legalize Freedom! Question Authority! "Im in love with the waitress, and I dont even know her name" "Boys" Gone Wild" ! Mainstreet Station 2012 Daytona Bikeweek Login or Register to Remove Ads
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02-21-2018, 02:10 PM	#4
DragonLady58 Sr. Member Join Date: Jul 2016 Location: Somewhere South of Alaska.... Posts: 2,351	Weeeeeeell, air being sucked into the hot exhaust is causing the problem, whether it be a leaking exhaust gasket, a crack in the rear pipe. The Old hoses that hook up to the reed valves and/or the reed valves themselves can also cause this.... Another idea, if all this checks out, and no problems found, a over rich mix in the FI or carb system, either by the carb being outta adjustment, or the FI system running a tuner....if the engine is running, some unburned gas enters the super hot exhaust, when you roll off throttle, you can get into popping, too. I've seen people with coasters involved, that they didn't clean the mounting/sealing surface enough, causing a air leak. Theres a leak somewhere thou. __________________ --------------------- Don't start no schit, there won't be no schit.... My Sarcasm is directly proportional to the amount of Stupidity involved --------------------- VBA#03239 VROC#37400 VRA --------------------- 2014 Vaquero 2001 Nomad FI 2003 Street Glide (sold) 1500 Meanie, fresh rebuild (sold) 90s BUBF Bobber (sold) 2001 UltraCycle FatPounder (Sold) 1975 HD ElectraGlide (Sold) 1982 Kawasaki Z1 Chopper (Sold) Suck It Up & Ride!
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02-21-2018, 08:27 PM	#5
ringadingh Join Date: Aug 2007 Location: Newmarket Ontario Canada Posts: 35,387	If you have Vance & Hines pipes, I'd bet that the rear pipe is cracked at the first bend. __________________ 2002 Nomad aka Bountyhunter VBA #27 VROC #18951 Login or Register to Remove Ads
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02-22-2018, 09:42 AM	#7
roadhawg Advanced Member Join Date: Feb 2012 Location: Starke Florida Posts: 856	Yes i have had cracked VH pipe and had it welded both times . last time they put 6 inch metal sleeve into weld and so far so good, but again i will check for leakage, thanks to all for your input! __________________ "Ride it like you stole it"! 2008 1600 Nomad 56K miles "BlueBelle" 2004 1500 Nomad 102 K miles "Black Beauty" ABATE Black Creek Chapter Amvet Rider Post 86 http://www.facebook.com/AmvetPost86 Weston A. Price Foundation member. Vegetarian...... An old Indian word meaning "Bad Hunter" Legalize Freedom! Question Authority! "Im in love with the waitress, and I dont even know her name" "Boys" Gone Wild" ! Mainstreet Station 2012 Daytona Bikeweek
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04-14-2018, 03:18 PM	#10
roadhawg Advanced Member Join Date: Feb 2012 Location: Starke Florida Posts: 856	I found a small hose that came off and put it back on and no more popping! Seems to run better too __________________ "Ride it like you stole it"! 2008 1600 Nomad 56K miles "BlueBelle" 2004 1500 Nomad 102 K miles "Black Beauty" ABATE Black Creek Chapter Amvet Rider Post 86 http://www.facebook.com/AmvetPost86 Weston A. Price Foundation member. Vegetarian...... An old Indian word meaning "Bad Hunter" Legalize Freedom! Question Authority! "Im in love with the waitress, and I dont even know her name" "Boys" Gone Wild" ! Mainstreet Station 2012 Daytona Bikeweek
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02-21-2018, 12:42 PM	#2
redjay Top Contributor Join Date: Feb 2008 Location: Ontario Posts: 6,926	It appears you have V&H pipes ? Is the rear header pipe cracked ?
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02-21-2018, 01:35 PM	#3
cbutoday Member Join Date: Oct 2017 Posts: 51	Sounds like an exhaust leak!
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02-21-2018, 08:53 PM	#6
ldhthept Sr. Member Join Date: Mar 2010 Location: Tallahassee FL Posts: 1,031	If pipe was cracked enough to cause popping he would prob be losing power and not run like a scalded dog. Just my 2 cents...
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02-22-2018, 11:01 AM	#8
redjay Top Contributor Join Date: Feb 2008 Location: Ontario Posts: 6,926	Are the acorn nuts on the exhaust flanges at the heads good and tight ? Sometimes they can bottom out and although they appear tight they are not. A washer or two under the nut cures that issue.
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04-12-2018, 05:22 PM	#9
duo1983 Member Join Date: Jan 2017 Location: Fresno, CA Posts: 52	When that happened to me I found that I had a broken piston and had to have a top end rebuild done
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04-14-2018, 07:49 PM	#11
mrtelefoneman1 Member Join Date: Oct 2010 Location: Zanesville, OH Posts: 315	Out of curiosity, where was this small hose located?
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04-15-2018, 08:14 PM	#12
roadhawg Advanced Member Join Date: Feb 2012 Location: Starke Florida Posts: 856	On backside of engine about halfway up, small tube that small hose goes on __________________ "Ride it like you stole it"! 2008 1600 Nomad 56K miles "BlueBelle" 2004 1500 Nomad 102 K miles "Black Beauty" ABATE Black Creek Chapter Amvet Rider Post 86 http://www.facebook.com/AmvetPost86 Weston A. Price Foundation member. Vegetarian...... An old Indian word meaning "Bad Hunter" Legalize Freedom! Question Authority! "Im in love with the waitress, and I dont even know her name" "Boys" Gone Wild" ! Mainstreet Station 2012 Daytona Bikeweek
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