Copper washers on bolts

[uteman]

Here comes another thing that I should have realised but did not so if I am dumb and dumber then accept that!
All of the bolts on the GS850 I am restoring were in very sad shape so I had them cleaned and re-coated with zinc.
My problem is that I overlooked (or more like did not realise) that the process would absorb all of the captive copper washers which were no doubt on many bolts to aid in restricting electrolysis between the steel bolts and the aluminium (spelt like an Aussie!) casings and also to aid in creating a sealing surface.
Many of these were 6 and 8 mm bolts.
Can anyone advise just which bolts should have copper washers?
It is easy enough to buy replacement washers and the bolts all look great now.

I would certainly do the same with bolts again but would log which bolts had the washers.

[Brendan W]

Now you have me thinking.
The only copper washers I have noticed on mine are on the outer pair of cylinder head bolts, that's two each side.

[Cipher]

fork drain bolts hve em

[Nessism]

There are very few copper washers. Only ones I know for sure are just loose washers, as mentioned above, on the outer head studs, and maybe the fork oil drains, although those may be soft aluminum washers instead.

[Steve]

Like the others, I am going to have to ask "which bolts"?

The only ones that I know of are loose washers on the outer head bolts, and that is not to prevent electrolysis, but because the space between the head and the stud carries oil. The copper washer is there to seal the opening when the nut is run down on it.

OK, there is a second area that uses copper washers, that would be the crush washers at the banjo bolts on the brake lines.

Again, those are 'loose', not 'captive' washers, so we are not sure which ones you are talking about.

.

[1948man]

Little copper washers under the screws that plug the ports for carb-synching. Not bolts, I guess. Maybe not copper but non-ferrous

[uteman]

Little copper washers under the screws that plug the ports for carb-synching. Not bolts, I guess. Maybe not copper but non-ferrous

I thank all who responded.
I am aware of the large washers under on outer head bolts and replacements are in the Vesrah gasket set that arrived yesterday.
This may remain a mystery but there were certainly a number of bolts from the engine that had the copper washers.
It may be that the washers were not originally captive but became so when crushed as bolts were tightened.
The process of acid dipping before the zinc coating was applied certainly "absorbed" them.
I have purchased a lot of parts from a local Suzuki shop who are quite friendly so will ask them if they can assist.

Thanks again folks.
PS:The link provided by "Nessism" on carb rebuild is appreciated and I will need that later on in the project.

[geol]

The copper washers under cylinder studs can be reused if they are heated till red hot then put in water. This is called annealing and restores the elasticity of the washers which are, as has been noted, useful for their crush-ability and keep oil from leaking from the oil journals that surround the outer engine studs.

[garyS-NJ]

Never thought about copoer to avoid electrolysis. As for annealing, with steel, you let it cool slowly. Quenching retains temper of something heated to form. Just googled annealing copper and one guy said heat red hot and slow cool. But when do we need to soften a copper washer? Are we saying crushing makes it hard like shot peening?

[Sandy]

If you look at one of the online parts diagrams it shows that the copper washers under the 4 outside head nuts are referred to as gaskets and all of the other washers, which are steel, under the remaining heads bolts are referred to as washers. Maybe somewhere along the way the steel washers got changed out with copper.