The Sportster and Buell Motorcycle Forum - The XLFORUM®
 

Go Back   The Sportster and Buell Motorcycle Forum - The XLFORUM® > SPORTSTER MOTORCYCLE FORUM > Sportster Motorcycle Intake and Exhaust > Sportster Motorcycle Air intake, Carburetor, EFI, Fuel, and Exhaust
XLF Blogs XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Notices

Sportster Motorcycle Air intake, Carburetor, EFI, Fuel, and Exhaust Problems, advice and/or how tos for Sporster and Buell motorcycle carburators, Electronic Fuel Injection (EFI), Air Intake, Fuel and Exhaust.

Active Threads
0 A Reliable Engine
Last Post: 73HEAD
Posted On: 46 Minutes Ago
Replies: 24
Views: 642
0 Keep & Kill
Last Post: Crusty
Posted On: 58 Minutes Ago
Replies: 26,704
Views: 1,548,737
0 Microsquirt EFI Conversion
Last Post: t120r
Posted On: 2 Hours Ago
Replies: 61
Views: 6,782
0 What song do you have stuck in your head?
Last Post: iNSaNeSHaNe
Posted On: 4 Hours Ago
Replies: 2,486
Views: 276,473
1 Hello from Cork, Ireland
Last Post: Stairman
Posted On: 4 Hours Ago
Replies: 6
Views: 58
0 04 Sportster refurb and build.
Last Post: JimVonBaden
Posted On: 4 Hours Ago
Replies: 106
Views: 8,180
0 My XLCH/XLR Hybrid build
Last Post: brucstoudt
Posted On: 5 Hours Ago
Replies: 18
Views: 614
0 What did you do to your EFI Sporty today?
Last Post: Steelrain
Posted On: 6 Hours Ago
Replies: 4,034
Views: 860,224
0 Official XL Forum Random Image Thread (NO NUDITY!)
Last Post: Graywolf
Posted On: 6 Hours Ago
Replies: 52,914
Views: 8,968,510
0 Coulda' - Shoulda' - Woulda' - Solenoid/Bendix?
Last Post: ZTatZAU
Posted On: 7 Hours Ago
Replies: 0
Views: 43
0 On board voltmeter
Last Post: ZTatZAU
Posted On: 8 Hours Ago
Replies: 12
Views: 702
0 Let's See Your Iron!!!
Last Post: Ghostdog
Posted On: 8 Hours Ago
Replies: 2,140
Views: 1,623,624
0 Aftermarket Ironhead Seats - ID?
Last Post: ZTatZAU
Posted On: 8 Hours Ago
Replies: 7
Views: 390
0 Iree's late night cafe
Last Post: rokytnji
Posted On: 8 Hours Ago
Replies: 2,215
Views: 395,059
3 Rear galiper bracket spec.
Last Post: DG Racing
Posted On: 8 Hours Ago
Replies: 1
Views: 106
0 1972 Build thread please subscribe
Last Post: wedge
Posted On: 8 Hours Ago
Replies: 167
Views: 25,148
0 Hot Rods, Rat Rods, and Customs.
Last Post: Stairman
Posted On: 8 Hours Ago
Replies: 4,899
Views: 1,004,972
0 Hottie of the day, no nudity.
Last Post: Stairman
Posted On: 9 Hours Ago
Replies: 33,840
Views: 4,071,079
0 Roads I'd like to ride.
Last Post: Stairman
Posted On: 9 Hours Ago
Replies: 3,738
Views: 441,581
0 extortion
Last Post: wedge
Posted On: 9 Hours Ago
Replies: 125
Views: 8,579
0 Primary chain tensioner, stock or M1 or other?
Last Post: gotamotor
Posted On: 10 Hours Ago
Replies: 8
Views: 443
0 Pushrod adjustment question
Last Post: gotamotor
Posted On: 10 Hours Ago
Replies: 12
Views: 846
0 Can't install kickstand spring
Last Post: RicThompson
Posted On: 10 Hours Ago
Replies: 13
Views: 438
0 Before and After pictures/Videos of your bike (All Welcome)
Last Post: Ghostdog
Posted On: 10 Hours Ago
Replies: 108
Views: 31,886
0 Snippets
Last Post: Crusty
Posted On: 11 Hours Ago
Replies: 591
Views: 83,158
0 1200T Build
Last Post: Ghostdog
Posted On: 11 Hours Ago
Replies: 6
Views: 527
0 This is gonna hurt.
Last Post: rokytnji
Posted On: 13 Hours Ago
Replies: 9,225
Views: 2,178,758
0 Massachusetts 2022
Last Post: joes95bobber
Posted On: 13 Hours Ago
Replies: 26
Views: 916
0 "The Blues" thread!
Last Post: rokytnji
Posted On: 13 Hours Ago
Replies: 1,108
Views: 157,241
0 Secondary Pulley Sprocket Quality
Last Post: SonWon
Posted On: 13 Hours Ago
Replies: 19
Views: 655
More...
Members Birthdays
hillclimber (72), burtondl2 (54), Cet (52), hagar71 (51), ShaneWolfe (50), grizdiesel (45), Confused89 (37), RAIDER0372 (36), spamer80 (36), svwannabe
Reply
 
Share Thread Tools Display Modes
  #1  
Old 4th December 2021
CaptainZoop CaptainZoop is offline
Biker
 
Join Date: Aug 2013
Posts: 38
Sportster/Buell Model: xl1000
Sportster/Buell Year: 1982
Reputation: 9681
CaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of light
Default Tuning a keihin butterfly

Hey guys, I'm trying to tune this keihin butterfly style carburetor on my 77 ironhead running open drag pipes and an air cleaner with a mesh insert with a 165 main jet but I am stumped at WOT. It starts fine, idle to 1/4 turn is fine, 1/4 to 3/4 turn is fine with hardly any flat spots, 3/4 to WOT pulls fine but then once I stay at WOT the bike stops accelerating and feels like it's hitting a wall then when I back off to 7/8 it slightly pulls again. I believe I'm running lean but do not have any jets at the moment as I cannot find a dealer locally. Can somebody link me to an online dealer where I can buy keihin "butterly" style main jets and NOT keihin "CV" style main jets? Please and thank you
Reply With Quote
  #2  
Old 5th December 2021
Hippysmack's Avatar
Hippysmack Hippysmack is offline
XL FORUM TEAM MEMBER
 
Join Date: Jul 2014
Posts: 8,207
Sportster/Buell Model: Xl1250S
Sportster/Buell Year: 98
Other Motorcycle Model: Kawasaki Vulcan 500
Other Motorcycle Year: 95
Reputation: 8403395
Hippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond reputeHippysmack has a reputation beyond repute
Default

If it pulls fine until sustained high RPM, it may not be the carb.
You may be wrapping excess oil around the flywheels.
Here is some info on wet sumping at high revs.
See if any of that sounds familiar.
http://sportsterpedia.com/doku.php/t...e_to_high_revs
__________________
Diagnosis begins before teardown, during and after rebuild.

In Search of Fuel, Sunshine and a Steady Idle.

Reference the XLFORUM'S Sportsterpedia
for additional technical information & advice
Reply With Quote
  #3  
Old 5th December 2021
bustert's Avatar
bustert bustert is offline
XL FORUM TEAM MEMBER
 
Join Date: Jul 2008
Posts: 10,730
Sportster/Buell Model: 1200s
Sportster/Buell Year: 2001
Sportster/Buell Model #2: xlch
Sportster/Buell Year #2: 1974
Reputation: 3396807
bustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond reputebustert has a reputation beyond repute
Default

jets-r-us
you may be out flowing the needle and seat on the inlet or maybe the float is not set right.
i think you are lean also as too rich will cause it to blubber.
have you tried the plug chop method to see what the plugs look like?
Reply With Quote
  #4  
Old 5th December 2021
Fivecats's Avatar
Fivecats Fivecats is offline
XL FORUM TEAM MEMBER
 
Join Date: Jan 2011
Location: Kelso, Washington
Posts: 357
Sportster/Buell Model: XLCH
Sportster/Buell Year: '68
Sportster/Buell Model #2: FXR
Sportster/Buell Year #2: '89
Other Motorcycle Model: R50/5
Other Motorcycle Year: '73
Reputation: 412401
Fivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond reputeFivecats has a reputation beyond repute
Default

"When I back off to 7/8 it slightly pulls again"... you are lean.

Do a keihin butterfly search here http://www.v-twinforum.com/forums/se...archid=1442573

Last edited by Fivecats; 5th December 2021 at 21:22..
Reply With Quote
  #5  
Old 5th December 2021
83XLX's Avatar
83XLX 83XLX is offline
Senior Master Custom Bike Builder
 
Join Date: Jan 2007
Location: Heart of Dixie
Posts: 8,258
Sportster/Buell Model: XLX-61
Sportster/Buell Year: 1983
Other Motorcycle Model: Honda CL350
Other Motorcycle Year: 1969
Reputation: 1034469
83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute83XLX has a reputation beyond repute
Default

I’m running a 170 main in my ‘83 with the Keihin carb, and it’s dialed in really well. Screaming Eagle air cleaner with a K&N filter, stock headers with Dyno-Power slip on mufflers. I’ve also removed the choke plate and shaft, and installed an Andrews high-flow accelerator pump kit in it.
__________________
I never wanted a Harley, but I always wanted a Sportster.

If it ain't broke, don't fix it (especially if you don't know what you're doing). Most Sportster problems are owner-induced.
Reply With Quote
  #6  
Old 12th December 2021
CaptainZoop CaptainZoop is offline
Biker
 
Join Date: Aug 2013
Posts: 38
Sportster/Buell Model: xl1000
Sportster/Buell Year: 1982
Reputation: 9681
CaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of lightCaptainZoop is a glorious beacon of light
Default

So I got my hands on a 170 main jet finally and problem solved. I can now WOT on the freeway without losing power. Also worth noting, a couple of times my choke plate would close after backfiring because I removed the choke lever to use it’s slot next to the ignition for a kill-switch. This caused a lean condition and made it impossible to go above 1/2 throttle. I wired the choke closed so that it will not happen anymore (but can still use it to warm up bike). Thanks everyone for tour help/input.
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 04:50.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC