Main bearing and primary guides advice

[Fleabie]

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

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.

[Trigger]

Never had to replace any rubber guides on a 400. Replace the chain and the primary rubbers 

[Bryanj]

Cant look at pics

[McCabe-Thiele (Ted)]

Google drive denied access so can't see any pics.

[Fleabie]

Sincere apologies about the link. Please try this one:

https://drive.google.com/drive/folders/1-4l59zFfLh2o1unInJ8F2s0PnhXnJJZs?usp=sharing

[Nurse Julie]

Yes, you need to replace the shells.

[Bryanj]

I agree with julie, thats water contamination and not enough oil changing

[Oddjob]

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.

[McCabe-Thiele (Ted)]

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.

[Matt_Harrington]

For reference, I bought the primary chain (Kawasaki) from www.motorcyclespareparts.eu/en
Kawasaki - 920571011 - CHAIN,PRIMARY,MA0364X50L   1   GBP 48.00   GBP 48.00
(Delivery was £7.95)

[Fleabie]

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!🙂

[Bryanj]

All questions will be answered--------eventually, and advice freely given, even actual help where possible

[Fleabie]

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.

[Bryanj]

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

[Bryanj]

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