Donate!
Welcome, Guest. Please Login or Register :: View Members
Pages: 1 2 
Send Topic Print
Crankshaft Blues (Read 170 times)
DragBikeMike
Serious Thumper
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 4071
Honolulu
Crankshaft Blues
12/02/19 at 00:19:28
 
So I'm reassembling the engine and I notice this.  Anyone seen anything like this before?  The right crank throw is black & blue around the gudgeon pin.  If something was burnin up it would be the rod, not the crank throw, right?  Does the factory use some sort of induction heater to build up the crank?  Do they weld the gudgeon on the right side to lock it in place?
Back to top
 

Crank_Black__Blue_1_2.JPG

Knowledge is power.
  IP Logged
DragBikeMike
Serious Thumper
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 4071
Honolulu
Re: Crankshaft Blues
Reply #1 - 12/02/19 at 00:20:09
 
Here is another angle.
Back to top
 

Crank_Black__Blue_2_2.JPG

Knowledge is power.
  IP Logged
DragBikeMike
Serious Thumper
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 4071
Honolulu
Re: Crankshaft Blues
Reply #2 - 12/02/19 at 00:20:46
 
And one more shot.
Back to top
 

Crank_Black__Blue_3_2.JPG

Knowledge is power.
  IP Logged
DragBikeMike
Serious Thumper
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 4071
Honolulu
Re: Crankshaft Blues
Reply #3 - 12/02/19 at 00:24:45
 
I have never seen anything like this.  If any of you know what this is I'd appreciate anything you can tell me about it.  It turns free, no evidence of rubbing, rod thrust washers look fine, no discoloration on the rod or the left hand crank throw.

Help!   Huh
Back to top
 
 

Knowledge is power.
  IP Logged
srinath
Serious Thumper
*****
Offline

I love YaBB 1G -
SP1!

Posts: 5349

Re: Crankshaft Blues
Reply #4 - 12/02/19 at 04:15:37
 
That's not from running. If it was, the motor would be a mess of melted metal. That's a weld heat signature.
Is the pin welded in this bike ? I've opened a few of these, I don't remember. I think its OK though.
Cool.
Srinath.
Back to top
 
 
  IP Logged
Armen
Serious Thumper
*****
Offline

Half-Witted
Wrench-Jockey from
Jersey

Posts: 1430

Re: Crankshaft Blues
Reply #5 - 12/02/19 at 05:16:48
 
Any chance someone tried to heat up the outboard crank bearing to get it off? I've never seed a crank pin welded from the factory.
Realistically, how many folks would have pulled apart the crank and rebuilt it?
Crazy.
Back to top
 
 

In theory, theory and reality are the same. In reality, they aren't...
  IP Logged
zevenenergie
Serious Thumper
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 1191
The Netherlands   Den Haag
Re: Crankshaft Blues
Reply #6 - 12/02/19 at 05:41:17
 
It can,t be rubbing. The blue spot is to small for that. It must be a weld.
Or maybe they induction heat before the put the pin in at the factory and some one wasn,t paying atention.
Back to top
 
 

Do what you know is right. (you can always use fear as a counselor later)
  IP Logged
srinath
Serious Thumper
*****
Offline

I love YaBB 1G -
SP1!

Posts: 5349

Re: Crankshaft Blues
Reply #7 - 12/02/19 at 09:22:39
 
Is it welded to the gear to its right ? I am pretty certain I have seen this before, only thing is, I don't remember on which bike. I did weld my XS650 into a 277 crank, that definitely had weld burns in every part of that crank.
Cool.
Srinath.
Back to top
 
 
  IP Logged
srinath
Serious Thumper
*****
Offline

I love YaBB 1G -
SP1!

Posts: 5349

Re: Crankshaft Blues
Reply #8 - 12/02/19 at 09:24:47
 
Look in a manual with pics. They do these disassembly etc etc and put pics in the manual. Clymer or Haynes is better than factory. Factory tends to do a lot of drawings, Haynes in fact says they pull the bike apart in their preface don't they ?
Cool.
Srinath.
Back to top
 
 
  IP Logged
Dave
YaBB Moderator
ModSquad
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 17738
Camp Springs, Kentucky
Gender: male
Re: Crankshaft Blues
Reply #9 - 12/02/19 at 12:53:13
 
It is normal I believe......the right side of the crank is a weird color and the other is not.  Your color pattern looks a bit different than the cranks I currently have open - but I don't see how the running engine could color the crank in the manner that yours is colored and still keep the needle bearing or thrust washers intact.

And if your crank got so hot that it blued while running.....I would suspect you would have cooked the oil that came in contact with the hot surface and you would see traces of burned oil sticking to the crank.

(NOTE:  The dark side is the right side.......regardless of how the photos got flipped around while posting).

Back to top
« Last Edit: 12/02/19 at 15:08:14 by Dave »  

IMG_4450.JPG

Someday I will be old......But not today!

  IP Logged
Dave
YaBB Moderator
ModSquad
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 17738
Camp Springs, Kentucky
Gender: male
Re: Crankshaft Blues
Reply #10 - 12/02/19 at 13:19:48
 
1 more
Back to top
 

IMG_4451.JPG

Someday I will be old......But not today!

  IP Logged
Dave
YaBB Moderator
ModSquad
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 17738
Camp Springs, Kentucky
Gender: male
Re: Crankshaft Blues
Reply #11 - 12/02/19 at 13:20:26
 
1 nother more
Back to top
 

IMG_4452.JPG

Someday I will be old......But not today!

  IP Logged
Ruttly
Serious Thumper
*****
Offline

Thumpers Rule

Posts: 4968
Manteca , CA
Gender: male
Re: Crankshaft Blues
Reply #12 - 12/02/19 at 14:19:29
 
Possible that that crank halves are different colors for assembly so workers don't put 2 of the same halves together. As far as the blue most likely heated on assembly and maybe reheated for alignment. Spins OK !

RUN IT !
Back to top
 
 

The Topic Terminator
  IP Logged
DragBikeMike
Serious Thumper
*****
Offline

SuzukiSavage.com
Rocks!

Posts: 4071
Honolulu
Re: Crankshaft Blues
Reply #13 - 12/02/19 at 22:17:14
 
Thanks very much for the comments & advice.  I appreciate the pictures Dave.  Since I did the initial post, I was able to find several photos of cranks (mostly eBay).  All these things seem to be black on the right and steel-grey/silver on the left.  That's pretty strange.  But I have yet to find any with the black & blue coloration indicative of major localized heating.

I'm not overly concerned since I see no way that the heating could be the result of operation.  It has to be related to manufacturing.  This is a 2016 model that I bought used when it was one-year old.  It had about 1050 miles on it and there is virtually no evidence that it had ever been disassembled.  I'm pretty confident it came from the factory with these black & blue marks.  

I beat it up real good.  If it hasn't failed yet I don't think the black & blue coloration is a problem.  It is very interesting though.  Almost seems like the OEM made some sort of change to their manufacturing process.  Probably figured out a more expedient way to build up the crank, or they welded the pin.

Anybody ever heard of an LS twisting the gudgeon?
Back to top
 
 

Knowledge is power.
  IP Logged
Armen
Serious Thumper
*****
Offline

Half-Witted
Wrench-Jockey from
Jersey

Posts: 1430

Re: Crankshaft Blues
Reply #14 - 12/03/19 at 05:07:38
 
FWIW, 'gudgeon pin' refers to wha the Yanks call a 'wrist pin'. The pin that holds the piston to the rod, not the rod to the crank.
Back to top
 
 

In theory, theory and reality are the same. In reality, they aren't...
  IP Logged
Pages: 1 2 
Send Topic Print


« Home

 
« Home
SuzukiSavage.com
03/29/24 at 03:54:03



General CategoryRubber Side Down! › Crankshaft Blues


SuzukiSavage.com » Powered by YaBB 2.2!
YaBB © 2000-2007. All Rights Reserved.