The Sportster and Buell Motorcycle Forum - The XLFORUM®
 

Go Back   The Sportster and Buell Motorcycle Forum - The XLFORUM® > SPORTSTER MOTORCYCLE FORUM > Sportster Motorcycle Motor / Engine > Sportster Motorcycle Engine Conversions
XLF Blogs XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Notices

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

Active Threads
0 Hi from Vermont
Last Post: Folkie
Posted On: 26 Minutes Ago
Replies: 8
Views: 158
0 Food porn
Last Post: Stairman
Posted On: 42 Minutes Ago
Replies: 2,296
Views: 496,139
0 Sportsters No More?
Last Post: AZbiker
Posted On: 50 Minutes Ago
Replies: 58
Views: 2,971
0 Hottie of the day, no nudity.
Last Post: cal43
Posted On: 52 Minutes Ago
Replies: 28,227
Views: 2,988,330
0 Keihin Butterfly Carb Float Level
Last Post: XL-Novice
Posted On: 1 Hour Ago
Replies: 3
Views: 22
0 Getting Out The Wrenches (was: Broken Exhaust Stud)
Last Post: ChinCactus
Posted On: 2 Hours Ago
Replies: 614
Views: 70,620
0 This is gonna hurt.
Last Post: Stairman
Posted On: 2 Hours Ago
Replies: 8,422
Views: 1,862,983
0 What’s your take on Harleys ceo putting down the sportster line
Last Post: Cmd11
Posted On: 2 Hours Ago
Replies: 27
Views: 1,212
0 Rocker lockers
Last Post: Pagey
Posted On: 2 Hours Ago
Replies: 2
Views: 43
0 Official XL Forum Random Image Thread (NO NUDITY!)
Last Post: cal43
Posted On: 3 Hours Ago
Replies: 50,280
Views: 8,249,159
0 Corona Virus
Last Post: iNSaNeSHaNe
Posted On: 3 Hours Ago
Replies: 1,568
Views: 152,794
0 Hot Rods, Rat Rods, and Customs.
Last Post: cal43
Posted On: 3 Hours Ago
Replies: 4,469
Views: 724,956
0 Hot Chicks on Hot Bikes
Last Post: cal43
Posted On: 4 Hours Ago
Replies: 11,860
Views: 2,510,222
0 Keep & Kill
Last Post: Graywolf
Posted On: 4 Hours Ago
Replies: 21,231
Views: 1,251,884
0 Why Harley-Davidson Owners Don’t Like the Street 500 and 750 Motorcycles
Last Post: Yeshua Johns
Posted On: 5 Hours Ago
Replies: 38
Views: 7,972
0 Are There Still Sober Riders On The Forum?
Last Post: Yeshua Johns
Posted On: 5 Hours Ago
Replies: 195
Views: 62,148
14 Firearms you wish you owned.
Last Post: Yeshua Johns
Posted On: 5 Hours Ago
Replies: 666
Views: 166,181
0 weight loss thread
Last Post: Yeshua Johns
Posted On: 5 Hours Ago
Replies: 69
Views: 27,080
0 Was your 1st bike a Sportster?
Last Post: Marsikus
Posted On: 5 Hours Ago
Replies: 1,049
Views: 278,304
0 what brand of spark plug do you use?
Last Post: sportsterdoc
Posted On: 5 Hours Ago
Replies: 349
Views: 89,745
0 New Sportster iron
Last Post: juzyHD
Posted On: 6 Hours Ago
Replies: 11
Views: 466
0 New Member From Nashville!
Last Post: juzyHD
Posted On: 6 Hours Ago
Replies: 13
Views: 697
0 Anyone go racing last weekend?
Last Post: Tinz
Posted On: 6 Hours Ago
Replies: 3,250
Views: 351,887
0 Iree's late night cafe
Last Post: ~Grind~
Posted On: 7 Hours Ago
Replies: 1,871
Views: 279,654
0 Ironhead Exhaust Poll
Last Post: IronMick
Posted On: 8 Hours Ago
Replies: 206
Views: 59,383
0 Hammer 1275 clang noise, slow oil feed, kinked crankcase vent.
Last Post: rocketmangb
Posted On: 10 Hours Ago
Replies: 356
Views: 9,260
0 New Lifters with new cams with your conversion?
Last Post: carbonizedeyesockets
Posted On: 10 Hours Ago
Replies: 3
Views: 217
0 Need a good dyno tuner!
Last Post: rocketmangb
Posted On: 10 Hours Ago
Replies: 1
Views: 106
0 WTB: Rear Turn Signals
Last Post: Polkahero
Posted On: 10 Hours Ago
Replies: 0
Views: 38
0 What does this mean? (Running Hot)
Last Post: IXL2Relax
Posted On: 10 Hours Ago
Replies: 1
Views: 83
More...
Members Birthdays
Slinkee, Bwarnerusa1, smoking man (61), dblkick (55), jkoj (55), Chena1 (52), iron goat (49), Uncle Fester (44), Don1903 (41), sporty93 (35), borada75xlch (33)
Reply
 
Share Thread Tools Display Modes
  #1  
Old 7th March 2021
painterdude923's Avatar
painterdude923 painterdude923 is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2013
Posts: 308
Sportster/Buell Model: sportster
Sportster/Buell Year: 2003
Reputation: 57618
painterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to beholdpainterdude923 is a splendid one to behold
Default 2003 1275 BFH compression?

Getting it out to enjoy some early spring riding! Checked compression, 210 front cylinder and 240 rear. Maybe that's why it seems to vibrate the gas cap loose at the end of the track. Should I yank it apart and raise compression in the front or lower in the rear to get it closer??
Reply With Quote
  #2  
Old 7th March 2021
Maxeffort's Avatar
Maxeffort Maxeffort is online now
Momentary Specialist
 
Join Date: Aug 2016
Posts: 1,060
Sportster/Buell Model: XL1200
Sportster/Buell Year: 1996
Other Motorcycle Model: ST1100
Other Motorcycle Year: 1999
Reputation: 1633296
Maxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond reputeMaxeffort has a reputation beyond repute
Default

Quote:
Originally Posted by painterdude923 View Post
Getting it out to enjoy some early spring riding! Checked compression, 210 front cylinder and 240 rear. Maybe that's why it seems to vibrate the gas cap loose at the end of the track. Should I yank it apart and raise compression in the front or lower in the rear to get it closer??
I’d assume piston height/quench distance was the same on both at assembly?

Cam timing checked?

Did you test compression after you put the 1275 together?

The low cylinder is the suspect.

Perform a leakdown test to determine cylinder condition. Listen if the low cylinder has air escaping the exhaust, intake or crankcase breather.

Now If leakdown is similar and it vibrates bad, I’d start to think about a bent connecting Rod.
__________________
“Smooth roads, Blue skies and Green lights”

Last edited by Maxeffort; 7th March 2021 at 19:57..
Reply With Quote
  #3  
Old 8th March 2021
seajay's Avatar
seajay seajay is offline
XL FORUM TEAM MEMBER
 
Join Date: Nov 2004
Location: jupiter fl
Posts: 2,844
Sportster/Buell Model: 1200C
Sportster/Buell Year: 04
Reputation: 969321
seajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond reputeseajay has a reputation beyond repute
Default

My hot compression was 210-212psi After a year and 3k miles went up to 215-218psi.
__________________
04/07 1275 BFH heads .590 Cat 4 cams S&S 1.725 rockers S&S premium lifters BDL+15% clutch TC88A HSR-45 S&S 3" ac LSR 2-1
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 13:01.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC