Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: Fleabie on July 12, 2023, 08:03:26 PM
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Hi,
I've read a lot on this forum about 400-4 crankshaft bearings. Its a bit daunting to be honest! I hope I don;t need to replace them. In the link below are some pictures taken this evening. Do people think these need replacing ?
https://drive.google.com/open?id=1-4l59zFfLh2o1unInJ8F2s0PnhXnJJZs&usp=drive_fs (https://drive.google.com/open?id=1-4l59zFfLh2o1unInJ8F2s0PnhXnJJZs&usp=drive_fs)
Also, I am fairly sure my primary chain needs replacing. When placed on a flat surface sitting on its side, the top links touch the bottom. I think this says "replace me"?
On the primary guides, the Haynes manual says minimum thickness 5mm. Mine are 6.1mm. Do people think that is good enough to reuse? It might be academic as I cannot find new ones anywhere!
Thanks in advance!
Bill.
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Never had to replace any rubber guides on a 400. Replace the chain and the primary rubbers ;)
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Cant look at pics
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Google drive denied access so can't see any pics.
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Sincere apologies about the link. Please try this one:
https://drive.google.com/drive/folders/1-4l59zFfLh2o1unInJ8F2s0PnhXnJJZs?usp=sharing (https://drive.google.com/drive/folders/1-4l59zFfLh2o1unInJ8F2s0PnhXnJJZs?usp=sharing)
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Yes, you need to replace the shells.
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I agree with julie, thats water contamination and not enough oil changing
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Have you checked the conrod shells yet? I would, just to be sure, I'd expect them to need replacing as well TBH.
Fit the Kawasaki primary chain instead of a Honda chain, it's the same chain but much cheaper. Not 100% sure but seem to recall the number is 92057-1011. It's around £48-50 where the Honda one is over £125 generally. Any Kwak dealer can order one.
Re-use the guides, if the chains new it's not generally touching them anyway. Don't forget to replace the primary damper rubbers at the same time, 8 of them.
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Depending on how long the bike has stood if the oil has been water contaminated I would be carefully checking the primary drive & gearbox bearings. In the grand scheme of things they are not expensive to replace if needed.
If you have any surface rust on the various steel shafts it should be easy enough to remove to avoid future problems.
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For reference, I bought the primary chain (Kawasaki) from www.motorcyclespareparts.eu/en (http://www.motorcyclespareparts.eu/en)
Kawasaki - 920571011 - CHAIN,PRIMARY,MA0364X50L 1 GBP 48.00 GBP 48.00
(Delivery was £7.95)
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Thanks all for the awesome advice. Unfortunately it has only lead to more questions.
Just digesting it all and doing some more research first before asking!🙂
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All questions will be answered--------eventually, and advice freely given, even actual help where possible
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Thanks all. What an awesome response to my post. I really appreciate it!
I didn't see any evidence of water in the oil, but I did find something plastic in the sump pan that had been slightly mangled. I think it was a plastic support for the metal oilway tubes in the top of the cylinder head. I seem to remember one dropping in many years ago. Not good I know but I wouldn't have expected much damage from a plastic foreign object.
Will get new primary chain, cam chain, drive rubbers. The Kawasaki links are much appreciated. I'll leave the primary guides as is. Going to thoroughly check the primary drive and bearings.
From previous advice, the mains shells do need replacing and based on that, I am fairly sure the big-end shells do as well. I am pretty sure the crank's journals are OK though. Very shiny with the occasional light streak on a couple of them.
So what's the process for selecting the correct shells? I've read lots of posts on this site and gone slightly mad in the process. The Haynes manual is a bit vague to me and I find it hard to understand :-( Is there a better guide anywhere that says this is what you should do?
So what I have gathered so far (taken me hours!):
Lower crank case stamps are: CCCCC
Crankshaft Webs: 2A 2A 2A 2A 2
Condrods marked: 2C 3C 2C 3C
My bearings have absolutely ZERO colour markings on them :-(
Am I right in thinking that if I measure the main and big end journals using a micrometer someone might be able to suggest the shells I use? Or do I need to get some other information first?
I don't currently have a micrometer big enough so was considering buying one. Unless someone near Sheffield would let me use theirs :-) What accuracy does it need go to ? I have seen some with
0.001mm resolution and 0.003mm accuracy. Would this be sufficient or would peeps recommend I get it measured by an engineering workshop?
Thanks in advance!
Bill.
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What i would do is get some plastigauge and check the clearance on the shells you have, from the codes you have given all the mains are the same and all the big ends the same.
If the clearance is in tolerance or just a bit big you can use the tables in the honda manual or parts book and get the same colour shells again.
Unless you are proficient with a micrometer its not worth you buying one as you wont be accurate enough.
Ash(ashimoto) is near Hull and may be able to help you if you ask him nicely.
EDIT
the mains are all the same C2 but the ends have 2 sizes A2 and A3 so as long as you have kept them where they came from you can still use plastigauge
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If you go to Ashs dropbox and look in the 400 parts book the tables are in there.
I make the mains black and the ends 2xyellow and 2xgreen
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Save your money and just buy the shells based on the markings, if they weren't badly marked etc they'll just be worn so the surfaces they are sitting in will still be fine. Plus plastigauge only really works with new shells or you're just measuring the wear in the old shells and unless you know what colour that is you're wasting your time.
Unfortunately the mains are all blacks and they ain't easy to find, there is only one shell bigger and that's blue and given a choice always fit a larger shell not smaller, of course always fit the right one whenever you can but what with availability that's not always possible. The conrods if you were going to replace them are 2 sets of yellows and 2 sets of green, A2 is yellow, A3 is green.
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Last time I looked (last week) DS had black mains in stock.
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He has 8 big end black shells Ted but no mains. None on the web either.
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Try Yamiya in japan
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He has 8 big end black shells Ted but no mains. None on the web either.
You are correct again Ken my Bad.
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Bill, I decided on a practical route regarding my main bearing shells. I used Plastigauge (a few times) to establish that the shells were within the service limits of the chart below (taken from the shop manual):
[attach=1]
I am getting close to the service limit BUT as the engine is not really going to be used that much, I decided to refit the shells. If I could have bought 'black' shells at a reasonable price, then I may have gone that route. (Webike - Japan did have them in stock a few weeks back...)
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I remember a post where somebody found a place in japan that did shells but may have been for a 500, as usual cant find it now
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Was it Webike Japan Bryan?
https://japan.webike.net/moto_news/
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Probably Ted. I mentioned it in my last post. Not sure if they have Blacks in stock at the moment, however.
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That link just takes me to a page i cant get away from but may well be the right firm
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Thanks all!
So I it looks like I need some blacks (or even blue) shells for the mains.
Sorry, I should have put these pics up before: https://drive.google.com/drive/folders/1FGK0xmXN2eiM9KJ9NTA5tb3KN_PbPNkR?usp=sharing (https://drive.google.com/drive/folders/1FGK0xmXN2eiM9KJ9NTA5tb3KN_PbPNkR?usp=sharing)
As I hope you can see in the pictures, I think the conrod shells needs replacing as well, but these seem to be easily available. As for the black main shells, as you all said, rare as rocking horse sh... Had a good Google hunt. I did find this site for shells possibly.
https://en.impex-jp.com/catalogs/moto/honda-other/cb400/cb400f-a-usa-6898/crankshaft-467977.html (https://en.impex-jp.com/catalogs/moto/honda-other/cb400/cb400f-a-usa-6898/crankshaft-467977.html)
If I need black shells, am I right in thinking I need "Rrg.a crank shaft 13315-333-003" ? I am not holding my breath but I have sent an enquiry to check availability, quantities etc. If it came to it, I would happily buy some extras and hold on to them for people seeking these in UK\Europe.
I did see this site that will make bespoke shells. https://vandervell.co.uk/custom-service/ (https://vandervell.co.uk/custom-service/) Could be pricey though. Has anyone gone down this route with a similar company?
Any ideas for black main shells gratefully received :-)
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13315-333-003 is the so called black mains shell part number I sold my last pair a couple of weeks or so ago to a member here.
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I remember a post where somebody found a place in japan that did shells but may have been for a 500, as usual cant find it now
It was David in Cumbria Bryan and for the 550 I believe.
Yamiya have most of the conrod colours including red and yellow which are kinda rare. They only have brown and green mains though. At a real pinch you could fit browns, not ideal but better than refitting the old shells.
Just looked at the pics. The rod shells are toast, unfortunately the journals are also in poor condition. Maybe think about replacing the crank entirely, at least you may get away with needing black shells that way.
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That impex site looks like the one i remember and yes the journals look scored from the one pic i got to open for me, sorry 2 i saw one shell which was bad.
Again dirty oil and lack of changes, maybe used crank and rods could be a better way to go
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Thanks people, I would be completely in the dark without your help.
I thought that the photos may have been showing things worse than they actually are. So I took the crank and rods to a local engineer. They said that the journals are fine to reuse as they are. They suggested a polish of the journals would be a good idea. They agree that the shells are all "past their best" :-)
Out of interest, how did people arrive at me having and needing black shells? I am guessing that its something todo with crank case, webs & rod marks but after that, I am in the dark!
I have sent a few messages out to people advertising the black main shells I would ideally refit, but with no joy. Oddjob suggested fitting blue mains but I can't find these anywhere either. I can currently get brown and greens mains. Are these shells an option with some engineering?
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There is a chart in the workshop manual and the parts book which you use the markings you listed to work out the correct shell size. Not green shells, too small. In order of thickness it goes on the 400, blue, black, brown, green, yellow, red. You could fit blue and just run it in slowly, black is the correct size but brown is a size under the correct size but at a real pinch you could use those. I was told by a Honda trainer it was ok to go up or down a size but not down 2. Ideally not up 2 either but at least the excess will wear away with a good running in..
I would suggest a polish would make the gap bigger as well. Plus for the cost of that just buy another crank, try and find one with the markings visible and ideally with the letters B on the crank journals not C. I doubt your engineer friend knows how fine the tolerances are on Honda cranks or he'd have agreed the crank is past it's best. Price up another crank, it's probably for the best.
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Here is the link I used for my 550 shells from Japan
https://en.impex-jp.com/catalogs/moto/honda-other/cb550/cb550k-a-1976-usa-6724/camshaft-crankshaft-455707.html
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Hi all,
Thanks for all the previous advice. It's all been very useful.
Well after much hunting I found some 'new' blue main shells. I could not get hold of the black ones for love nor money. So I have had to go up a size, which by all accounts is safe to do, as long as you run it in sensibly. I say 'new' because these shells are not in original Honda packaging but they have been carefully labelled with the correct part code in hand writing. I can also see the blue dot of colour on their sides, so that's very reassuring. So fingers crossed, they are what they have been sold as. I am going to clean up my case and check the shells with plastiguage.
The shell's look 'new', but they have horizontal marks across them i.e. perpendicular to the direction of rotation where you would expect to see marks on shells that have been used. Attached are 3 pictures of just one 'new' shell. Perhaps they have been tested in a crank case, and then found to be not suitable? But I would not expect a new shell to have any blemishes. The blemishes seem light enough to me but just want to check in with the experts :-) N.B. As before, these images greatly exaggerate how they look in real life ! Please bare that in mind when viewing the images. Is it normal for new shells to have these blemishes?
Thanks in advance!
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Typical New old stock that haven't been stored in the original brown oiled paper.
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Yup, bad storage
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Ok, thanks for the replies.. Does this mean they are unusable?
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No, useable just run in with care
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So the saga continues... slowly. I fitted and torqued down the <cough> "new" blue main shells with plastigauge. The first plastigauge I used (PL-X) showed a clearance>0.045mm (i.e. off the scale for that plastiguage type).So I then bought plastigauge PL-A and this shows a clearance of more like 0.076mm which means the clearance is at the service limit (0.08mm). So what to do next :-(
Originally I a was trying to source black shells, but I cannot find these for love nor money. I am beginning to wonder if black ones would give quite high clearances. So what would people do next ? Go the other way and get a set of brown main shells ones ? (seeing as the clearance is so large with the blues.)
TIA, Bill.
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Its inside the limit so use them
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Thanks Bryan. Your help is much appreciated :-)
Would there be any harm in fitting brown shells? Would they be better in the long run as it would give a a tighter main shell clearance ? i.e. better oil pressure, longer life of engine etc?
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I thought black was thickest then blue, if so brown would be even looser
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I could be wrong here but I think it goes brown, black then blue in terms of giving increasing mains clearance. I got this from looking at the shell tables on page 32 of the manual on Ash's link:
(https://www.dropbox.com/s/1n3w5433jkph228/350F%20400F%20_4%20Shop%20Manual.pdf?dl=0 (https://www.dropbox.com/s/1n3w5433jkph228/350F%20400F%20_4%20Shop%20Manual.pdf?dl=0))
I think that if have (according to plastigauge) approximately a 0.08mm clearance at the moment with blue shells, if I went down to browns I could knock of 0.02mm bringing it down the clearance to 0.06mm. If that's right then perhaps I could go even further down and go for green main shells as this would bring the clearance down by 0.03mm from the blues to 0.05mm. Although a 0.05mm clearance is above ideal, its much well within the upper service limit of 0.08mm.
Would anyone agree/disagree? If I am going to do this, it might as well be as best as I can get it :-)
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I think you are reading it wrong, smallest journal with biggest case hole needs thickest shell(blue)
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Sorry, I am being a bit dim :) Your are right, I was reading it wrong. The way you worded it makes perfect sense now. So yes, I guess it’s stick with the blues or get a new crank (as you advised earlier in this thread).
Thanks Bryan!