Harley Davidson Forums

Touring Models Road King, Road King Custom, Road King Classic, Road Glide, Street Glide, Electra Glide, Electra Glide Classic, and Electra Glide Ultra Classic bikes.
Sponsored by:
Sponsored by:

Backfire on first start up

Thread Tools
 
Search this Thread
 
Old Jan 12, 2020 | 10:06 AM
Share
  #1  
sB43's Avatar
sB43
Thread Starter
|
Cruiser
Joined: Nov 2017
Posts: 246
Likes: 20
From: Front Royal, VA
Default Backfire on first start up
2000 Ultra classic. I just ad new S&S 509G Camchest installed w/plate, and installed new Cobra true duals and NH slip ons. When I first turn the key, let fuel pump do it's thing, then hit starter button, she backfires and cranks. I turn the key off for a second, turn it back.... hit the start button and she usually fires up. Any suggestions? Also, have Cobra Fuel tuner.
(M&M EFI)
 
Reply
0
Old Jan 12, 2020 | 10:20 AM
Share
  #2  
dawg's Avatar
dawg
Seasoned HDF Member
Shutterbug
Liked
Loved
Community Favorite
Joined: Jun 2006
Posts: 28,476
Likes: 3,950
From: Vermont
Default
Did it backfire prior to you changing cams and tune?
 
Reply
0
Old Jan 12, 2020 | 10:25 AM
Share
  #3  
sB43's Avatar
sB43
Thread Starter
|
Cruiser
Joined: Nov 2017
Posts: 246
Likes: 20
From: Front Royal, VA
Default
No dawg, it did not
 
Reply
0
Old Jan 12, 2020 | 10:27 AM
Share
  #4  
dawg's Avatar
dawg
Seasoned HDF Member
Shutterbug
Liked
Loved
Community Favorite
Joined: Jun 2006
Posts: 28,476
Likes: 3,950
From: Vermont
Default
Was it a canned map that you put in the tuner? Assuming timing and everything is all set with cam install, I’d look at the tune.
 
Reply
0
Old Jan 12, 2020 | 10:28 AM
Share
  #5  
19special's Avatar
19special
Banned
Joined: Jul 2019
Posts: 477
Likes: 117
From: https://t.me/pump_upp
Default
2000 and fuel pump means M&M injection I believe.
 
Reply
0
Old Jan 12, 2020 | 10:39 AM
Share
  #6  
dawg's Avatar
dawg
Seasoned HDF Member
Shutterbug
Liked
Loved
Community Favorite
Joined: Jun 2006
Posts: 28,476
Likes: 3,950
From: Vermont
Default
Originally Posted by 19special
2000 and fuel pump means M&M injection I believe.
Correct, he indicated it was MM EFI. Hard to tune sometimes unless the person dyno tuning knows their way around them.
 
Reply
0
Old Jan 12, 2020 | 10:40 AM
Share
  #7  
sB43's Avatar
sB43
Thread Starter
|
Cruiser
Joined: Nov 2017
Posts: 246
Likes: 20
From: Front Royal, VA
Default
Yes Sir, I even unplugged the ECM to re-think what's new. (Hoping that it would see new hardware).
 
Reply
0

Trending Topics

Old Jan 12, 2020 | 10:42 AM
Share
  #8  
sB43's Avatar
sB43
Thread Starter
|
Cruiser
Joined: Nov 2017
Posts: 246
Likes: 20
From: Front Royal, VA
Default
Yeah, it's not been re mapped.> I had the tuner before I did the cam and exhaust. she'd usually hit on the first hit of the switch.
 
Last edited by sB43; Jan 12, 2020 at 10:43 AM.
Reply
0
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

7 Surprising Harley-Davidson Products that Are Not Motorcycles

 Verdad Gallardo
story-1

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-2

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-3

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-4

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-5

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-6

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-7

10 Motorcycles You Should Never Buy

 Joe Kucinski
story-8

10 Things Harley-Davidson Needs to Fix in 2026

 Verdad Gallardo
story-9

Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider

 Verdad Gallardo
Old Jan 12, 2020 | 10:46 AM
Share
  #9  
sB43's Avatar
sB43
Thread Starter
|
Cruiser
Joined: Nov 2017
Posts: 246
Likes: 20
From: Front Royal, VA
Default
Yeah, my indy hates this M&M, and is trying to talk me into going carb. I'm leaning toward his recommendation. I hate this M&M! Never had problems with my old EVO.
 
Reply
0
Old Jan 12, 2020 | 10:50 AM
Share
  #10  
dawg's Avatar
dawg
Seasoned HDF Member
Shutterbug
Liked
Loved
Community Favorite
Joined: Jun 2006
Posts: 28,476
Likes: 3,950
From: Vermont
Default
Zippers conversion is another option, albeit pricier than getting parts for the carb conversion if buying used.
 
Reply
0



Advanced Search
Reply Closed Thread Share
Forum Jump

All times are GMT -5. The time now is 01:31 PM.

story-0
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-1
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-2
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-3
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-4
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-5
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-6
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-7
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-8
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE
story-9
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider

Slideshow: Graeme Billington's left-hand-drive Shovelhead is as much about problem-solving as it is about classic Harley form.

By Verdad Gallardo | 2025-12-30 11:27:08


VIEW MORE