« previous next »
Pages: 1 [2] 3

Author Topic: 72 cc LC bbk installation tips  (Read 4840 times)

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #15 on: February 24, 2015, 05:15:17 AM »
I just fixed the mis spellings in my reply.

How did you even understand whayt I sayiddid. :o
Logged
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #16 on: February 24, 2015, 04:47:06 PM »
I just kinda made up words in place of the nonsense lol.  The funny bit is that this is the ad that was shown with your reply

Logged
Almost...at...speed...limit... Aww, brake lights..

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #17 on: February 24, 2015, 08:25:37 PM »
Well,  when on the wrist pin and in the arm it seems rather solid.  But off of the pin it seems wore out.  The bearings have a lot of play.  Maybe you can see,  and at the end, hear,  what I'm talking about. 
https://www.dropbox.com/s/i8401spdhknbli6/20150224_151612.mp4?dl=0
I'm sure that putting in a new one wouldn't hurt,  regardless.
Logged
Almost...at...speed...limit... Aww, brake lights..

chaz35

  • Hero Member
  • *****
  • Posts: 711
  • old guy
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #18 on: February 24, 2015, 11:06:17 PM »
Is that play new since it was originally assembled, before it was run?

Well IDK, but seems to me if nice and tight when assembled then OK.  You are seeing the bearings loose in the cage, IDK but not surprised is loose when not assembled with wrist pin in piston and roller bearing in small end of rod.  You didn't show in your vid, but how much play is there when fully assembled?

The critical clearance is between the wrist pin, roller bearing, and small end of the rod.  Not the clearance of the roller bearings in the cage, which is what is loose best I can tell.
Logged
1st and 2nd usually have an unfair advantage.  3rd is usually the best, can learn the most from.  paraphrased from Don Quixote, over 400 years ago, still true today

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #19 on: February 25, 2015, 12:41:49 AM »
Here's a little video,  might shine some light on the situation.  On a tore down gy6 engine I have the connector rod has similar play at the cam.  Again,  I'm not sure of the tolerances of these,  as this is new to me. 
https://www.dropbox.com/s/r0camlghcmtfa53/20150224_193417.mp4?dl=0
Logged
Almost...at...speed...limit... Aww, brake lights..

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #20 on: February 25, 2015, 12:50:15 AM »
Quote from: Triesandluth on February 24, 2015, 04:47:06 PM
I just kinda made up words in place of the nonsense lol.  The funny bit is that this is the ad that was shown with your reply




2nd funniest ever..... I'm cryin ,lingerestingedionorination
Logged
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #21 on: February 25, 2015, 12:52:56 AM »
Quote from: Triesandluth on February 24, 2015, 08:25:37 PM
Well,  when on the wrist pin and in the arm it seems rather solid.  But off of the pin it seems wore out.  The bearings have a lot of play.  Maybe you can see,  and at the end, hear,  what I'm talking about. 
https://www.dropbox.com/s/i8401spdhknbli6/20150224_151612.mp4?dl=0
I'm sure that putting in a new one wouldn't hurt,  regardless.


That bearing is SHOT.

Also grab your connecting rod in the TDC position. Try to move it side to side. IF it is good there will be no motion. If the big end of the crank is shot it will sort of rock back, and forth.

It's not a huge job to replace the crank if needed

The last bit is to grab each side of the crank (flywheel / variator) and see if there is any play in the crank bearings. ANY movement is a done deal.

« Last Edit: February 25, 2015, 12:57:46 AM by zombie »
Logged
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #22 on: February 25, 2015, 12:53:45 AM »
What about the play in the connector rod to the cam?
Logged
Almost...at...speed...limit... Aww, brake lights..

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #23 on: February 25, 2015, 12:58:35 AM »
Look up one post...
i just edited the last one.
Logged
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #24 on: February 25, 2015, 01:16:13 AM »
Oops.  I see.  It wasn't long ago that I checked the crank bearing play.  At the time there wasn't,  but I'll check again. 
I would have to split the case to change the crank,  right?  Wouldn't it be wise to do the crank bearings at the same time?

 Edit: there's virtually no play in the crank bearing area.  But there is some play,  a millimeter or so,  in every position at the connector rod to the cam...
« Last Edit: February 25, 2015, 01:26:21 AM by Triesandluth »
Logged
Almost...at...speed...limit... Aww, brake lights..

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #25 on: February 25, 2015, 01:33:17 AM »
Well,  I did find this,  and other similar answers in a Google Search
http://www.thumpertalk.com/topic/505423-connecting-rod-side-play/
Claims of light side play being normal.  I don't have up and down play.  Nice and tight there.
Logged
Almost...at...speed...limit... Aww, brake lights..

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #26 on: February 26, 2015, 10:14:39 AM »
Ordered the bearing.  Should be here by Monday.  I'm gonna need to find a way to send you beer money,  zombie!
Logged
Almost...at...speed...limit... Aww, brake lights..

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #27 on: February 26, 2015, 02:33:51 PM »
Quote from: Triesandluth on February 25, 2015, 01:33:17 AM
Well,  I did find this,  and other similar answers in a Google Search
http://www.thumpertalk.com/topic/505423-connecting-rod-side-play/
Claims of light side play being normal.  I don't have up and down play.  Nice and tight there.

By side play they are referring to end play. There should be around 1mm of direct horizontal "slide in the crank /con rod. There should also be Zero diagonal play ie: rocking of the crank. The tiny amount of 2t oil on the parts make it difficult to feel this wear if you just push, up / down.

If there is ANY sort of rocking feeling go ahead, and order a crank. It comes w/ bearings. I would also order 2 sets of crank seals, and double those up.

I'v nad engines run for several thousand miles w/ worn big ends, so it's not too dramatic but the noise will tell you when it's time to replace it.

Since you really can't feel the play it's got to be borderline, and not critical...

For beer bucks..., donate a bag of dog food to the local animal shelter. Maybe play w/ a dog for an hour.It'll make you both smile!   ;D ;D ;D
Logged
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Triesandluth

  • Hero Member
  • *****
  • Posts: 813
  • Getting it, a mile per hour at a time
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #28 on: February 26, 2015, 09:04:32 PM »
He he he,  you said nad....

I'm going to put that on a to do list for down the road.  After putting the wrist pin bearing in,  even if it's not ticking anymore,  I'm thinking that this will no longer be my daily and have it more as a pain in the ass project bike,  still not a racer though.  Really still looking at the tgb I saw.  The kid lowered the price drastically and I'm sure if I go see it and throw a few hundred bucks at him that he'll sell.

For the dog food and shelter,  don't mind if I do!  I gotta be careful with playing with them though...  I'll want to take one home.  I can't do that until I move into my house with a yard,  hopefully this summer.  I plan to have a dog run,  maybe get a few to keep my daughter company. 
Logged
Almost...at...speed...limit... Aww, brake lights..

zombie

  • You never know do ya!
  • Hero Member
  • *****
  • Posts: 13870
  • Close enough to get the idea!
    • View Profile
Re: 72 cc LC bbk installation tips
« Reply #29 on: February 26, 2015, 11:15:11 PM »
That's why I suggested playing with one.

You can never go home alone...   ;D

It's all good.  nad!
Logged
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

An Error Has Occurred!

Call to undefined function split()
Back