Author Topic: Crank not rotating  (Read 1957 times)

Offline alexdecker

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Re: Crank not rotating
« Reply #30 on: May 07, 2022, 07:29:44 PM »
The black one I'd replace, both of them, it's not really a good idea to mix a new and a worn one on the same journal. Left in I think it will end up scoring the journal surface.  The black shell can only have come from either number 2 or number 4 journal, as the ONLY combination to use a black shell is a C2.

As I said though, finding black shells is difficult, 13315-323-000 is the part number, CMS did have some months ago but they've gone now and they weren't cheap when they were available, they are showing them as selling for £11.25 or so but I can guarantee that when they were available they were a LOT dearer, I think they reduce the price of the part when it sells out so that they can buy someone else's stock and claim they aren't worth as much. Sure they were close to £28 a shell when they did have them, plus P&P of course.

I'm not keen on the state of the rest of the shells TBH, that scoring on the upper edge is worrying, not sure how long this engine may have been stood but to me the surfaces of the shells look contaminated and that's why they are starting to break up. I'd replace all the crankshaft ones if it were mine, I'd also check the rods shells just in case.

£230 for both or each?

Ah, the black shell was actually from the number 5. I don't know what the signs of a previously opened bottom end is, but somebody must have opened it before me. I marked the positions of the bearings when taking it apart, and that black one can not have been anywhere else than there.

I will use a micrometer on the crank and try and figure out what the correct bearing sizes should be, and source some new ones. What are the options of I can't source a particular color? I will also open up the rod and see how they look like in there. Man, was hoping I could avoid all this. But hey, might as well now, as long as Im in here. This turned out to be quite a lot more expensive than I thought it would be.

And yes, £230 as a collected price for both :)

PS: Are the rod bearings just as rare as the crank bearings?
« Last Edit: May 07, 2022, 07:33:16 PM by alexdecker »

Offline Bryanj

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Re: Crank not rotating
« Reply #31 on: May 07, 2022, 07:51:31 PM »
If you cant get a particular size go for the next thickest shell, i have in the past fitted all black shells and done some carefull running in, which you dont have to do if you get the Honda spec clearance right

Offline Oddjob

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Re: Crank not rotating
« Reply #32 on: May 07, 2022, 08:14:10 PM »
Look for markings on the crank

Rod shells are getting rare, especially the black and yellow ones.
Don't play stupid with me, I'm better at it

Offline alexdecker

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Re: Crank not rotating
« Reply #33 on: May 07, 2022, 08:19:01 PM »
Look for markings on the crank

Rod shells are getting rare, especially the black and yellow ones.

The markings on the crank seems to have disappeared completely. But it’s just a matter of measuring and matching up, like with the crank journals, right?

Offline McCabe-Thiele (Ted)

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Re: Crank not rotating
« Reply #34 on: May 07, 2022, 10:32:10 PM »
The markings are not in plain sight it took me ages to find mine as I was either looking in the wrong place or not seeing them. Eventually I found most of the. After cleaning the Crank with petrol using a paint brush.
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Offline alexdecker

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Re: Crank not rotating
« Reply #35 on: May 08, 2022, 04:09:42 PM »
Took of the rods today. Can you guys help me with the condition of the bearings? I feel like there is a big difference in how they look like, and how they feel like. In the pictures, number 1, 2 and number 4 feels silky smooth, with number 3 having some trouble. But just looking at them, they all look a bit weathered. I don't know how to judge it. Any tips is really appreciated.

They had the following colors and the journals the measurements (in mm):
1. Brown 34,97
2. Brown 34,97
3. Brown 34,98
4. Green 33,02

All the journals are smooth with no marks whatsoever. I have yet to wash the crank down with petrol, so still can't see the numbers and letters on the crank.
« Last Edit: May 08, 2022, 04:11:51 PM by alexdecker »

Offline alexdecker

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Re: Crank not rotating
« Reply #36 on: May 08, 2022, 04:10:06 PM »
Rod bearing 1:

Offline alexdecker

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Re: Crank not rotating
« Reply #37 on: May 08, 2022, 04:10:32 PM »
Rod bearings 2:

Offline alexdecker

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Re: Crank not rotating
« Reply #38 on: May 08, 2022, 04:10:52 PM »
Rod bearings 3:

Offline alexdecker

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Re: Crank not rotating
« Reply #39 on: May 08, 2022, 04:11:13 PM »
Rod bearings 4:

Offline alexdecker

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Re: Crank not rotating
« Reply #40 on: May 08, 2022, 04:26:31 PM »
Also, I measured the crank journals for the main bearings. My case is BCBCB. I got these measurements in mm:

1. 32,96
2. 33
3. 32,95
4. 33
5. 32,95

Does these numbers make sense? The shop manual only shows this in inches - does an official source with metric measurements exists, that I can use to determine what color bearings? The colors I pulled out, from 1 to 5, was: Brown, Green, Brown, Green, Black

Offline McCabe-Thiele (Ted)

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Re: Crank not rotating
« Reply #41 on: May 08, 2022, 04:27:54 PM »
Make sure the conrod surface where the shells sit is nice & clean - then I would Plastigauge all the bearings this gives you an accurate clearance measurement for the journals that you can check against the manual tollerances charts.
Honda CB400 four super sport

Offline alexdecker

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Re: Crank not rotating
« Reply #42 on: May 08, 2022, 04:30:44 PM »
Make sure the conrod surface where the shells sit is nice & clean - then I would Plastigauge all the bearings this gives you an accurate clearance measurement for the journals that you can check against the manual tollerances charts.

But can I still use plastigauge as an accurate measurement when both the bearing and the journal is worn? Then the numbers might not correspond to the correct size when buying new shells? Or am I misunderstanding something?

Offline Bryanj

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Re: Crank not rotating
« Reply #43 on: May 08, 2022, 05:07:57 PM »
If the clearance is still inside tollerance then they are safe to reuse

Offline Seabeowner

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Re: Crank not rotating
« Reply #44 on: May 08, 2022, 07:08:34 PM »
Also, I measured the crank journals for the main bearings. My case is BCBCB. I got these measurements in mm:

1. 32,96
2. 33
3. 32,95
4. 33
5. 32,95

Does these numbers make sense? The shop manual only shows this in inches - does an official source with metric measurements exists, that I can use to determine what color bearings? The colors I pulled out, from 1 to 5, was: Brown, Green, Brown, Green, Black
The crank journals when new go from 32.98 - 33.00mm.   Class 1 is 32.99 - 33.00.   Class 2 is 32.98 - 32.99.  Presume this stayed consistent through all 500/550s.
Only way to get accurate clearance on a used motor  for the DIYer is with plastiguage really.
Phil
1971  CB500K0  Candy Jade Green
1973  CB500K1  Candy Ruby Red
1975  CB550F1   Shiny Orange
1978  CB550K     Excel Black

 

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