The Sportster and Buell Motorcycle Forum - The XLFORUM®
 

Go Back   The Sportster and Buell Motorcycle Forum - The XLFORUM® > SPORTSTER MOTORCYCLE FORUM > Sportster Motorcycle Era Specific and Model Specific > XR Sportster Motorcycle Talk - XR750, XR1000, XR1200
XLF Blogs XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

XR Sportster Motorcycle Talk - XR750, XR1000, XR1200 For XR Sportsters: XR750, XR1000, XR1200

Active Threads
0 Battery melt down
Last Post: ryder rick
Posted On: 3 Minutes Ago
Replies: 9
Views: 196
0 Common ironhead problems
Last Post: IronMick
Posted On: 5 Minutes Ago
Replies: 15
Views: 28,507
0 Post up how many wheels you have in your household
Last Post: SLW210
Posted On: 10 Minutes Ago
Replies: 6
Views: 108
0 1960 XLCH in the UK
Last Post: IronMick
Posted On: 11 Minutes Ago
Replies: 241
Views: 28,208
0 back to factory clutch
Last Post: Mark Jags
Posted On: 22 Minutes Ago
Replies: 39
Views: 4,059
0 Best Riding/Motorcycle Memes-Let's see 'em!
Last Post: DK Custom
Posted On: 30 Minutes Ago
Replies: 281
Views: 59,355
0 This is gonna hurt.
Last Post: Crusty
Posted On: 34 Minutes Ago
Replies: 7,998
Views: 1,662,276
0 Hottie of the day, no nudity.
Last Post: Stairman
Posted On: 36 Minutes Ago
Replies: 17,702
Views: 1,782,649
0 15 min rides
Last Post: drandall1489
Posted On: 47 Minutes Ago
Replies: 4
Views: 57
0 Keep & Kill
Last Post: Crusty
Posted On: 1 Hour Ago
Replies: 16,128
Views: 918,400
0 For those of you who have never seen one,
Last Post: thefrenchowl
Posted On: 1 Hour Ago
Replies: 15
Views: 1,120
0 Front cylinder base gasket leak
Last Post: thefrenchowl
Posted On: 1 Hour Ago
Replies: 4
Views: 113
0 HELP! Extra part found
Last Post: syrnetworkin
Posted On: 1 Hour Ago
Replies: 8
Views: 87
0 Hello from Tampa, Fl
Last Post: Steve9
Posted On: 1 Hour Ago
Replies: 12
Views: 193
0 Replacement Clutch/Rotor Magnets
Last Post: bustert
Posted On: 1 Hour Ago
Replies: 15
Views: 6,726
0 Resto-Repair 84 ironhead
Last Post: Yochstein
Posted On: 1 Hour Ago
Replies: 8
Views: 159
3 Wtb, Wts, Wtt, Wtg (Ironhead)
Last Post: Gold Member
Posted On: 1 Hour Ago
Replies: 49
Views: 251,441
0 Official XL Forum Random Image Thread (NO NUDITY!)
Last Post: Graywolf
Posted On: 2 Hours Ago
Replies: 46,755
Views: 7,449,260
0 Getting Hammered
Last Post: Bryan1976
Posted On: 2 Hours Ago
Replies: 128
Views: 13,694
0 Greetings from Denmark
Last Post: Highly-Dangerous
Posted On: 2 Hours Ago
Replies: 9
Views: 75
0 Howdy ya'll
Last Post: Highly-Dangerous
Posted On: 2 Hours Ago
Replies: 9
Views: 125
0 Hot Chicks on Hot Bikes
Last Post: joes95bobber
Posted On: 2 Hours Ago
Replies: 10,662
Views: 1,954,612
0 removing clear coat on fork lowers
Last Post: NLXL
Posted On: 3 Hours Ago
Replies: 3
Views: 100
0 Corona Virus
Last Post: Crusty
Posted On: 3 Hours Ago
Replies: 253
Views: 12,505
0 Need some advice on 1983 Ironhead
Last Post: flthd31
Posted On: 4 Hours Ago
Replies: 34
Views: 2,716
0 Upside Down Monoshock IH - A Longterm Project
Last Post: chilly
Posted On: 6 Hours Ago
Replies: 159
Views: 34,050
0 88ci Sport Rod
Last Post: jkinkade
Posted On: 7 Hours Ago
Replies: 691
Views: 119,244
0 Another from the Phoenix area
Last Post: Hippysmack
Posted On: 9 Hours Ago
Replies: 10
Views: 187
0 48 O2 sensor?
Last Post: Tomcatt
Posted On: 10 Hours Ago
Replies: 2
Views: 91
0 Phoenix AZ
Last Post: sportsterpaul
Posted On: 11 Hours Ago
Replies: 11
Views: 456
More...
Members Birthdays
Sponsored Links
Reply
 
Share Thread Tools Display Modes
  #1  
Old 20th March 2018
Ftrack51 Ftrack51 is offline
XL FORUM TEAM MEMBER
 
Join Date: Mar 2018
Posts: 5
Sportster/Buell Model: XR750
Sportster/Buell Year: 1980
Reputation: 10
Ftrack51 is an unknown quantity at this point
Default Iron XR750 advice

Just joined the XL Forum as I am looking for advice on building an iron XR motor ideally in the late '71 factory team configuration with two rear mounted carbs and front exhausts.
Q.1: which H-D workshop manual best reflects the internals of this motor, '59-69 K KH XL XLH XLCH or '70-78 XL XLH XLCH, or are any differences minimal/irrelevant?
Q.2: is there any source of NOS or useable flywheels and con-rod sets? Will rods from an alloy XR do the job?
Q.3: I have been told to look for -57 heads with small ports but there appears to be a choice of casting numbers 16681, 16682, 16683 and 16684. Which are best?
Reply With Quote
  #2  
Old 30th March 2018
barefoot barefoot is offline
Senior Bike Builder
 
Join Date: May 2012
Posts: 1,914
Sportster/Buell Model: XR 750
Sportster/Buell Year: 1972
Sportster/Buell Model #2: RR 250
Sportster/Buell Year #2: 1976
Reputation: 271483
barefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond repute
Default

Quote:
Originally Posted by Ftrack51 View Post
Just joined the XL Forum as I am looking for advice on building an iron XR motor ideally in the late '71 factory team configuration with two rear mounted carbs and front exhausts.
Q.1: which H-D workshop manual best reflects the internals of this motor, '59-69 K KH XL XLH XLCH or '70-78 XL XLH XLCH, or are any differences minimal/irrelevant?
None of those. The iron XR is closer to the XLR than any of those. Even then the crank is different.

Quote:
Q.2: is there any source of NOS or useable flywheels and con-rod sets? Will rods from an alloy XR do the job?
Flywheels no. Conrads are the same as the current XR. Or similar enough to use, anyhow. In iron XR days they had pressed-in races. New ones are carburized one-piece, otherwise the same. There's also 1" longer ones of the same design that you could use but those would be old. The crankpin is different and many of the bearings are different.

Quote:
Q.3: I have been told to look for -57 heads with small ports but there appears to be a choice of casting numbers 16681, 16682, 16683 and 16684. Which are best?
It doesn't matter. If you plan to duplicate any of the factory bikes you'll be getting real friendly with brass rod and a torch. They were brazed up by hand.

Lots of work involved for second-rate stuff. Easiest way to get where you want to go is probably scrounge a current XR and fit iron heads and barrels. The iron XR stuff broke. A lot. The crank is particularly bad.
Reply With Quote
  #3  
Old 1st April 2018
Ftrack51 Ftrack51 is offline
XL FORUM TEAM MEMBER
 
Join Date: Mar 2018
Posts: 5
Sportster/Buell Model: XR750
Sportster/Buell Year: 1980
Reputation: 10
Ftrack51 is an unknown quantity at this point
Default

Many thanks for the information; that certainly helps to map out the project.
Reply With Quote
  #4  
Old 2nd April 2018
barefoot barefoot is offline
Senior Bike Builder
 
Join Date: May 2012
Posts: 1,914
Sportster/Buell Model: XR 750
Sportster/Buell Year: 1972
Sportster/Buell Model #2: RR 250
Sportster/Buell Year #2: 1976
Reputation: 271483
barefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond repute
Default

Quote:
Originally Posted by Ftrack51 View Post
Many thanks for the information; that certainly helps to map out the project.
Ja, building an iron xr as it was done in 1970 would be replicating all the things that broke, not making something nice. You can't tell from the outside that an alloy xr is not an iron one (except for the heads and barrels) but they fixed a bunch of stuff internally. The whole crank arrangement is different. Just use late-model stuff.

Late-model in this case means 1972

It would be like reproducing an early 6V92, when they broke a lot. The later good ones look exactly the same but work great, so why copy stuff that's bad ?
Reply With Quote
  #5  
Old 2nd April 2018
Bob F's Avatar
Bob F Bob F is offline
XLF LIFEMEMBER Im retired
 
Join Date: Feb 2007
Location: Pittsburgh, PA
Posts: 14,402
Sportster/Buell Model: XL50 0596 Black
Sportster/Buell Year: 2007
Other Motorcycle Model: E-Glide
Other Motorcycle Year: 2003
Reputation: 866963
Bob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond repute
Default

Welcome to the XLForum.
__________________
Bob, a glutton and a winebibber, a friend of bartenders and sinners!
Reply With Quote
  #6  
Old 2nd April 2018
Ftrack51 Ftrack51 is offline
XL FORUM TEAM MEMBER
 
Join Date: Mar 2018
Posts: 5
Sportster/Buell Model: XR750
Sportster/Buell Year: 1980
Reputation: 10
Ftrack51 is an unknown quantity at this point
Default

Thanks again Barefoot, I will aim to set up the iron motor like my alloy XR, or alternatively look for a turbo-diesel truck engine ;-)
Reply With Quote
  #7  
Old 4th April 2018
barefoot barefoot is offline
Senior Bike Builder
 
Join Date: May 2012
Posts: 1,914
Sportster/Buell Model: XR 750
Sportster/Buell Year: 1972
Sportster/Buell Model #2: RR 250
Sportster/Buell Year #2: 1976
Reputation: 271483
barefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond reputebarefoot has a reputation beyond repute
Default

Quote:
Originally Posted by Ftrack51 View Post
... alternatively look for a turbo-diesel truck engine ;-)
If yer lookin for the race version, maybe an 8V53. Mmm, do they sound nice
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



Sponsored Links
All times are GMT +1. The time now is 16:41.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC