Harley Davidson Forums

Sportster Models 883, 883 Custom, 1200 Custom, 883L, 1200L, 1200S, 1200 Roadster, XR1200, and the Nightster.
Sponsored by:
Sponsored by:

Lifter noise or knock due to exhaust leak?

Thread Tools
 
Search this Thread
 
  #1  
Old 05-18-2018, 10:57 PM
DruWO's Avatar
DruWO
DruWO is offline
6th Gear
Thread Starter
Join Date: May 2018
Location: Los Angeles
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Default Lifter noise or knock due to exhaust leak?
Greetings. I recently picked up this 1998 sportster XL1200S with 14k miles(my first Harley!). Just got her running. I do notice this knocking at idle and low RPM’s, it seems to go away after 3-3.5k. I have noticed an exhaust leak at the front cylinder, so it may be pre detonating? I’ve tried to retard the timing, doesn’t change much. I’ve tried some air/fuel screw play, no change. I’m guess I need to address the lifter? I do plan on 1250 stroker kit with in the next few weeks because compression is running low, and the cylinder head has a few broken fins on them. Cold compression test is reading around 172psi front (the knocking cylinder) and 180psi rear cylinder. Just trying to figure out what this noise could be before I start the tear down.

Heres a a link to a video.

thanks in advance!
 
Reply Like
  #2  
Old 05-19-2018, 07:09 AM
apache snow's Avatar
apache snow
apache snow is offline
Road Warrior
Join Date: Sep 2017
Location: over the mountain
Posts: 1,609
Received 693 Likes on 453 Posts
Default
A 1250 kit changes the bore not the stroke. Compression is not bad for a stock bike.
 
Last edited by apache snow; 05-19-2018 at 07:10 AM.
Reply Like
  #3  
Old 05-19-2018, 08:28 AM
Dudepants's Avatar
Dudepants
Dudepants is offline
Road Warrior
Join Date: Aug 2016
Location: Minneapolis, MN
Posts: 1,568
Received 596 Likes on 333 Posts
Default
It sounds like the noise i was getting. Mine was (as apache snow correctly diagnosed) a bad lifter. Replaced them with S&S lifters i bought from Hammer Performance and the noise went away completely. But if you’re getting an intake or exhaust leak it could be a different story.
 
Reply Like
  #4  
Old 05-19-2018, 10:01 AM
HOTLAP's Avatar
HOTLAP
HOTLAP is offline
Seasoned HDF Member
Join Date: Feb 2007
Location: Edmonton Alberta Canada
Posts: 5,064
Received 389 Likes on 298 Posts
Default
That sounds like a deeper sounding knock than a lifter to me, more like a wrist pin or connecting rod/crank knock.
 
Reply Like
  #5  
Old 05-19-2018, 10:14 AM
apache snow's Avatar
apache snow
apache snow is offline
Road Warrior
Join Date: Sep 2017
Location: over the mountain
Posts: 1,609
Received 693 Likes on 453 Posts
Default
Yeah when I had a bad lifter it had a more metallic sound. Not as deep as yours.
 
Reply Like
  #6  
Old 05-19-2018, 10:22 AM
DruWO's Avatar
DruWO
DruWO is offline
6th Gear
Thread Starter
Join Date: May 2018
Location: Los Angeles
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Default
Originally Posted by HOTLAP
That sounds like a deeper sounding knock than a lifter to me, more like a wrist pin or connecting rod/crank knock.
i was thinking the same thing, but when I listened with a pair of stethoscopes all the noise is coming from the top end. The bottom end is silent.
 
Reply Like
  #7  
Old 05-19-2018, 08:57 PM
DruWO's Avatar
DruWO
DruWO is offline
6th Gear
Thread Starter
Join Date: May 2018
Location: Los Angeles
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Default
Pulled the jugs off. Front rod has an ton of play, bearing is toast. I have assessed the condition of the crank shaft. Is this worth rebuilding? Or am I better off buying a complete motor to swap in?
 
Reply Like

Trending Topics

  #8  
Old 05-20-2018, 06:10 AM
apache snow's Avatar
apache snow
apache snow is offline
Road Warrior
Join Date: Sep 2017
Location: over the mountain
Posts: 1,609
Received 693 Likes on 453 Posts
Default
You can have side to side play, just no up and down play.
 
Reply Like
  #9  
Old 05-20-2018, 06:57 AM
Kingglide549's Avatar
Kingglide549
Kingglide549 is offline
Banned
Join Date: May 2018
Location: Viet Vet, crossroads
Posts: 4,576
Received 969 Likes on 694 Posts
Default
Pretty sure you went passed what was wrong....
The noise is 1/2 speed of the crank, so it is valve train related.
 
Reply Like
  #10  
Old 05-20-2018, 11:08 AM
DruWO's Avatar
DruWO
DruWO is offline
6th Gear
Thread Starter
Join Date: May 2018
Location: Los Angeles
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Default
Originally Posted by apache snow
You can have side to side play, just no up and down play.
theres a ton of up and down play... I’ll get a little deeper today.


Originally Posted by Kingglide549
Pretty sure you went passed what was wrong....
The noise is 1/2 speed of the crank, so it is valve train related.
i did also notice that the 4 main 1/2 inch bolts that hold down the rocker box wasn’t torqued down properly. Two bolts with enough play to spin the washers underneath them. Weird thing is that the rocker boxes weren’t leaking.

anyhow, I found a decently priced ‘99 xl1200s motor. Would this be a direct swap? Would I find any differences in electrical or ignition systems?
 
Reply Like



Advanced Search
Quick Reply: Lifter noise or knock due to exhaust leak?


Reply Closed Thread Share
Forum Jump

All times are GMT -5. The time now is 04:24 PM.