Crank bearings good or bad

[Acro1985]

Thanks Ted

I have sent you a reply

[taysidedragon]

I've sent you a PM I only have a pair of used Green Mains for a 500 for you to try for size using Plastigauge, sorry no used Browns or used big end shells with markings.

Used shells won't give accurate clearance information because of the wear on them. New shells should be used to get accurate information.

[McCabe-Thiele (Ted)]

I've sent you a PM I only have a pair of used Green Mains for a 500 for you to try for size using Plastigauge, sorry no used Browns or used big end shells with markings.

Used shells won't give accurate clearance information because of the wear on them. New shells should be used to get accurate information.

Agreed but if a set of half decent used Green shells give you a clearance of say 55 microns you can be pretty confident that a set of Browns will be good. Likewise if your clearance with used Greens is 38 microns then Greens are good!

I've lent a sohc member here  some used 400 shells previously - it worked for him as a starting point.

Paying out for a new set of Greens to find you need Browns is an expensive exercise if you have no legible shell colour markings. I would not have offered my shells if they were badly worn. One set out of three Greens I kept for such future use for myself or to help a member here.

If a member here has a spare  set on new unused shells  to sell at a reduced price or to lend out then clearly that would be better still.

[Murf]

The numbers or letters are can be really indistinct,  just scratched on, I think it was just a production line thing and not for the rebuilder 40 years later. In general one colour will dominate but you can’t rely on that. Look on the side of the shells for any trace of colour. Get a magnifying glass and a torch and check the parts at various angles to see if you can find the marks or numbers.  On the CBX they used a mixture of letter, numbers and Roman numerals!!!  If all that fails  Getting a new pair of shells as a test set is a great idea.
But have checked the original bearings yet because if they are ok then you don’t need to worry about all this.  I know it’s nice to change everything and have a virtual new engine, but I also think you have to take into consideration of how the bike will be used in the future. If you are going to thrash it or go long distance touring then change the bearings. If you are going to give it a nice quiet life with regular oil changes etc then maybe it’s ok on the old bearings.

[Acro1985]

After cleaning the crank with petrol and WD40 and then trying various different lighting in the garage and the garden (My wife thinks I have finally lost the plot). I can defiantly make out four number 1s on the crank, and from my crude measurement of the journals 33mm this seems to correspond with workshop manual for the crank being a number 1. I haven't been able to find any paint on the shells yet, thought maybe I found some brown paint but think this is just burnt on oil as it mostly rubbed with a bit of petrol/degreaser and a paper towel.

just waiting for the plastigauge to be delivered so I can check the clearance between the crank and shells.

 

[Acro1985]

Any tips on getting the paint of the cases?? mine appears to have been painted silver, then black.  the black comes off really easily it just wipes off if sprayed with WD40 or a bit of petrol. but the silver seems to be far better quality (assuming this maybe factory). I was thinking possible paint stripping??

[McCabe-Thiele (Ted)]

I used Paramose Paint Stripper - it's for trade use only as it contains some nasty chemicals that work. Modern over the counter stuff like Nitromoors are imho useless.

You will need to use the right safety gear, right mask, eye protection plus appropriate long chemical resistant gloves. It's nasty stuff hence the restriction on retailing.
Once down to bare metal after washing off I used wet a dry to remove any bad surface oxidation.

After painting the cases silver - oven baked to cure.

[Acro1985]

I used Paramose Paint Stripper - it's for trade use only as it contains some nasty chemicals that work. Modern over the counter stuff like Nitromoors are imho useless.

You will need to use the right safety gear, right mask, eye protection plus appropriate long chemical resistant gloves. It's nasty stuff hence the restriction on retailing.
Once down to bare metal after washing off I used wet a dry to remove any bad surface oxidation.

After painting the cases silver - oven baked to cure.

I will have choose a day when the wife's not in to bake them as she will go spare with me 😂

[Acro1985]

Has anyone got an idea as to were I can a 57mm ring set from as whoever put the engine back together last time left this and the 52mm one out. Which explains why drive socket seemed loose and moved in and out from the crankcase as the entire shaft was moving 🤦.

It's showing as out of stock on CMS website and DS don't list it. Done a search of the web and nothing comes up where it's in stock

[Bryanj]

I think i have a 550 bottom end lying about and may be convinced to split it

[Acro1985]

I think i have a 550 bottom end lying about and may be convinced to split it

Hi Bryan what would it take to convince you to split it or to part with the whole bottom end

[Bryanj]

Energy!

[Nurse Julie]

If  Bryan can't be tempted to split that engine, we've got a box of assorted half rings here that I can look through.

[Acro1985]

If  Bryan can't be tempted to split that engine, we've got a box of assorted half rings here that I can look through.

Thanks Julie, if you could that would be greatly appreciated plus I need to buy a set of your brass swing arm bushes too.

[Nurse Julie]

If  Bryan can't be tempted to split that engine, we've got a box of assorted half rings here that I can look through.

Thanks Julie, if you could that would be greatly appreciated plus I need to buy a set of your brass swing arm bushes too.

I'll get Graham to have a rummage through the box and I'll send you a PM later.