EVO All Evo Model Discussion

Help with mid range popping

Thread Tools
 
Search this Thread
 
Old Nov 16, 2013 | 07:51 AM
  #1  
Raineman's Avatar
Raineman
Thread Starter
|
Tourer
Joined: Jul 2013
Posts: 273
Likes: 35
From: Central MD
Default Help with mid range popping

I have a '98 FLHT (carbed EVO)and I have a running issue.

When I am at cruising rpm, and sometimes during acceleration, I get a brief slight power loss and a "POP" which I think is coming out of the carb. It does this fairly regularly, but not always, and it happens at a certain part of the throttle (I can almost tell when it is going to happen based on feel). If I go above or below the spot in the throttle, it does not do it. Just seems like it is at that one spot.

I have played with the mixture very slightly, but no improvement.

I think I am just going to replace the intake gaskets and rebuild the carb, but would like to at least try and diagnose it before I do so, just to learn. If its simpler than I am making it, that'd sure be nice.

Any thoughts or suggestions?

(and sorry if I did not provide enough info, let me know what other info you may need)

Oh yeah...a can of Seafoam didn't fix it...
 

Last edited by Raineman; Nov 16, 2013 at 07:54 AM.
Reply
Old Nov 16, 2013 | 12:28 PM
  #2  
Hackd's Avatar
Hackd
Elite HDF Member
Joined: Oct 2005
Posts: 3,872
Likes: 83
From: Canton, Michigan
Default

Intake manifold seals, or carb to manifold seal. Or both.

Quite possible your carb needs a good cleaning. How's the idle???
 
Reply
Old Nov 16, 2013 | 02:10 PM
  #3  
aces&8s's Avatar
aces&8s
Seasoned HDF Member
10 Year Member
Liked
Loved
Community Favorite
Joined: Sep 2012
Posts: 6,570
Likes: 590
From: almost there
Default

You might have solved it by saying intake leak. Maybe even Exhaust leak.? Carb Pop, Advanced timing.?
 
Reply
Old Nov 16, 2013 | 04:37 PM
  #4  
Larry Ashcraft's Avatar
Larry Ashcraft
Cruiser
Joined: Aug 2013
Posts: 210
Likes: 12
From: Colorado
Default

Most likely jetted too lean. Mine was doing that. Took it to a good independent shop and it's all better now.
 
Reply
Old Nov 16, 2013 | 05:50 PM
  #5  
Hackd's Avatar
Hackd
Elite HDF Member
Joined: Oct 2005
Posts: 3,872
Likes: 83
From: Canton, Michigan
Default

Originally Posted by Raineman
When I am at cruising rpm, and sometimes during acceleration, I get a brief slight power loss and a "POP" which I think is coming out of the carb. It does this fairly regularly, but not always, and it happens at a certain part of the throttle (I can almost tell when it is going to happen based on feel). If I go above or below the spot in the throttle, it does not do it. Just seems like it is at that one spot.
Exactly like my bike was doing at 70 mph. Roll the throttle on easy, and it would 'miss' and pop out the carb.

New manifold seals and a clean carb, solved the issue.
 
Reply
Old Nov 16, 2013 | 05:53 PM
  #6  
Killerman#1's Avatar
Killerman#1
Cruiser
Joined: Oct 2013
Posts: 148
Likes: 0
From: East Texas
Default kehin butterfly carb.

My 87 FLT had a kehin butterfly" not a CV" carb that did that. tried lots of things to fix problem, "adjusted timing, intake seals, exhaust seals, riching up fuel mixture, etc." Ended up chunking the thing over the fence, "the Carb.", an put on an S&S super "E", Problem went away. I'm pretty sure it was a lean condition caused by the old Carb. Used to get around 40mpg with the Kehin, now getting 35mpg, Oh well!!! She don't spit in public no more.
Killer
 
Reply
Old Nov 17, 2013 | 12:10 PM
  #7  
tomfiii's Avatar
tomfiii
Cruiser
Joined: Aug 2010
Posts: 181
Likes: 13
Default

My '86 had a problem due to the accelerator needle not seating under nozzle resulting in no gas squirting on 2nd twist of throttle.
 
Reply
Old Nov 17, 2013 | 02:10 PM
  #8  
Kushman's Avatar
Kushman
Tourer
Joined: Jan 2012
Posts: 259
Likes: 1
From: Kingston, Ontario
Default

Originally Posted by aces&8s
You might have solved it by saying intake leak. Maybe even Exhaust leak.? Carb Pop, Advanced timing.?
All things to check, you can use carb cleaner and spray around the intake seals, listen for a change in rpm that would indicate a leak.
Another thing would be the cable adjustment, had this happen before turned out cables were out of adjustment and when the acc. Pump sprayed it would hit the butterfly, you could smell gas and would get a pop when the"puddle" would get sucked into the air valve on the carb.
I also just did the exhaust gaskets on my 06 last guy never tightened the bolts and two were gone the other two just on, it was pretty evident by the pop and you could tell there was a leak by looking at it.
If you guys have a winter like us now I would be rebuilding the carb with cvpreformance parts, new gaskets intake and possibly exhaust while you have the time. The cv Caribs easy to work on and you will gain another level of understanding your ride.
 
Reply
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 Nov 18, 2013 | 08:26 AM
  #9  
Raineman's Avatar
Raineman
Thread Starter
|
Tourer
Joined: Jul 2013
Posts: 273
Likes: 35
From: Central MD
Default

Thanks for the replies. I didn't get to do much on it this weekend, just a lot of cleaning and waxing.

Will do the carb cleaner test this coming weekend, then pull the carb and rebuild it and replace all the intake/exhaust gaskets as I get some free time this winter.

Hackd, the idle seems fine.
 
Reply
Old Nov 18, 2013 | 05:44 PM
  #10  
Hackd's Avatar
Hackd
Elite HDF Member
Joined: Oct 2005
Posts: 3,872
Likes: 83
From: Canton, Michigan
Default

Originally Posted by Raineman
Hackd, the idle seems fine.
After running at highway speed for a bit, and then going to a stop, does it seem to idle higher than normal? Or does it consistently settle down to the same RPM?
 
Reply



All times are GMT -5. The time now is 09:11 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