The Sportster and Buell Motorcycle Forum DK Customs  

Go Back   The Sportster and Buell Motorcycle Forum > SPORTSTER MOTORCYCLE ZONE > Sportster Motorcycle Motor / Engine > Sportster Motorcycle Engine Conversions
XLF Gallery XLF Classifieds XLF Blogs XLF Shout XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Sportster Motorcycle Engine Conversions Advice, questions, and tips for 1200, 1250, 1340, 1450 etc... for Sportster and Buell motorcycle engine conversions

Members Birthdays
Energy One Clutches
Biltwell
BIKE BUILDER
Biltwell

Sky Smith Insurance
Reply
 
Share Thread Tools Display Modes
  #11  
Old 8th May 2012
proturn's Avatar
proturn proturn is offline
Harley Engineer
 
Join Date: Mar 2012
Location: Central Minnesota
Posts: 332
Sportster/Buell Model: 883c/1203xb
Sportster/Buell Year: 2006
Sportster/Buell Model #2: 1994 XL1200
Other Motorcycle Model: 1998 Heritage ST
Reputation: 15731
proturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of lightproturn is a glorious beacon of light
Default

It's your Exhaust. I have never come across a bike with drag pipes that didn't do what you described. Make Sure your front exhaust pipe is sealing at the head. (notorious leak spot) if you see black soot anywhere around either of your exhaust ports you'll know you have leak. Leaks lead to a lean mixture and on the cam overlap (just before your exhaust valve closes, your intake valve is opening) the new air and fuel is pre- igniting.

Proturn
www.tpemachine.com
Reply With Quote
  #12  
Old 9th May 2012
Sporty B Sporty B is offline
Biker
 
Join Date: May 2012
Posts: 21
Sportster/Buell Model: XL883
Sportster/Buell Year: 1997
Reputation: 154
Sporty B is on a distinguished roadSporty B is on a distinguished road
Default

A little update; I went out today just to start the engine. I noticed that it is just the front exhaust pipe that was crackling and popping. I pulled the plugs and they both look fine, they should have about 2000 miles on them. I was wondering why only 1 exhaust was causing noise. I found there was a leak somewhere from my carb, just a little fuel from under it. I am not sure if it is related or not, but I am going to check the jets and see if they have been changed. I am starting to think like milmat1 is. I will go to my local Harley dealer tomorrow and check on some seals and gaskets, jets and maybe baffles. Once I get it back together then I will go from there. Does anyone have anything they want to add, something I should know, tips tricks? This carb seems very simple.

Update: looks like it has the stock jets and the adjustment screw cover has not been removed. I don't think the carb was every gone though after all the mods.
Reply With Quote
  #13  
Old 9th May 2012
77cr237 77cr237 is offline
Biker
 
Join Date: Feb 2012
Location: in the country
Posts: 21
Sportster/Buell Model: XLCR
Sportster/Buell Year: 1977
Other Motorcycle Model: 1974 FLH, 1972 BMW R75/5
Reputation: 39
77cr237 is an unknown quantity at this point
Default

Quote:
Originally Posted by proturn View Post
It's your Exhaust. I have never come across a bike with drag pipes that didn't do what you described. Make Sure your front exhaust pipe is sealing at the head. (notorious leak spot) if you see black soot anywhere around either of your exhaust ports you'll know you have leak. Leaks lead to a lean mixture and on the cam overlap (just before your exhaust valve closes, your intake valve is opening) the new air and fuel is pre- igniting.

Proturn
www.tpemachine.com
He's right about the exhaust. A leak at the head can let oxygen enter there on deceleration. There will be high-temp, unburned fuel coming out of the engine and when the oxygen is pushed in by atmospheric pressure, it causes the fuel to explode in the pipe. Jerry
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


Custom Search

All times are GMT +1. The time now is 12:51.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
XL Forum - Linson Media LLC