I bought this CB550K3 at Auction

[gbjeppm]

Hi All,

Further to my intro post, I said that i would post up how I am getting along, so I am starting a project thread.

I bought a CB550 K3 (Registered Jan 1979), Chassis number CB550K-202*****. Seems a little odd that it is a Jan 1979 bike yet it is a K3, but i am not arguing with DVLA. It is a UK registered bike, that is HPI Clear, and has not been on the road since 2006.

That is it as far as History is concerned. Bought at auction with no V5. The speedo says it has done approx 26k miles.

The bike arrived from the auction house a couple of days ago by courier, and I have started to get into it, to assess what I have, what is missing, what needs doing etc.

Here are a few pics of the initial state.


The Exhaust



The Front Rim



So hopefully you get the general idea. My hope was that it would still clean up well, as most of the rust was surface rust, and with a lot of elbow grease it could be dealt with.

Here is a shot of the right hand  pipes after a bit of effort with the wire wool.

[Nurse Julie]

Looking better already. Wire wool is so underestimated

[gbjeppm]

So i start to go through the bike to potentially think about starting it.

It has oil in it at the right level, it has spark on at least the two outside cylinders (I have ordered the correct spark plug socket, so that i can get the middle one's out.)

I opened the Carb drain screws up, and nasty green sludge dropped out, so I removed the carbs, stripped and cleaned them. Most of the jets were blocked, and most of the float bowls stuck.

Luckily the fuel tank was empty, and not too bad, so that should be fine to use when I am ready.

Amyway with a temp fuel tank hooked up, and a new battery, all of the lights lit up, the starter whirred and she came to life on the 4th press of the starter.

Definitely running a bit rough, and cylinder 3 is not firing at all as far I can tell.

I have ordered new plugs, along with the spark plug tool. So when they arrive I can change all the plugs, and test for compression etc and hopefully dial the bike in properly.

Also ordered a new clutch cable, fuel tank front rubber, horn (it was missing), oil, oil filter etc,

Slightly cleaner, lots more cleaning to do while I wait on parts.

[robvangulik]

You do know wire wool works best when lubed with a bit of diesel or petroleum?

[hondarc166]

looking better now looking at your pillar drill is it  made in swadlincote by o bryans i think they called it fobco ?

[gbjeppm]

looking better now looking at your pillar drill is it  made in swadlincote by o bryans i think they called it fobco ?

Yes it is a Fobco, its a fantastic drill

[gbjeppm]

You do know wire wool works best when lubed with a bit of diesel or petroleum?

Yes thanks

[MrDavo]

You spot the pillar drill, I have bike lift envy....

I grant you that the wire wool has done a good job with the rust, but how durable is the result? Will it come out in a rash of rust spots after being out in the rain?

[SteveD CB500K0]

I’m sure my K3s (I had three or four in the day) had no front stay on the front mudguard.


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[SteveD CB500K0]

Eg:








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[kevski]

K3's had stays, including my 500k3

[K2-K6]

"I grant you that the wire wool has done a good job with the rust, but how durable is the result? Will it come out in a rash of rust spots after being out in the rain?"

Good question. It's one of those things that generally is not looked at very closely.  The chrome doesn't rust, chromium being the significant element making steel "stainless" when alloyed with steel.

The visible rust is the steel structure material corrosion coming out through pores in the chrome plate.  In effect not curable,  but rub it off and keep just a little oil on it, and it'll stay reasonably good but difficult with hot exhaust.

As I understand it,  really good protective chrome would use nickel and copper "undercoat" with decorative chrome to finish, effectively making impermeable barrier to the base steel rusting.

Think all chrome of this era ultimately needs coating with oil to preserve it as it's more decorative than long term protection.

[gbjeppm]

"I grant you that the wire wool has done a good job with the rust, but how durable is the result? Will it come out in a rash of rust spots after being out in the rain?"

Good question. It's one of those things that generally is not looked at very closely.  The chrome doesn't rust, chromium being the significant element making steel "stainless" when alloyed with steel.

The visible rust is the steel structure material corrosion coming out through pores in the chrome plate.  In effect not curable,  but rub it off and keep just a little oil on it, and it'll stay reasonably good but difficult with hot exhaust.

As I understand it,  really good protective chrome would use nickel and copper "undercoat" with decorative chrome to finish, effectively making impermeable barrier to the base steel rusting.

Think all chrome of this era ultimately needs coating with oil to preserve it as it's more decorative than long term protection.

I have no doubt that the exhausts are rusting from the inside out, and in fact the no 3 pipe has a couple of holes on the underside of the silencer about 10 cm after the join to the header. I think i am going to get a  stainless patch tig welded in to it to make it solid, but i am a little concerned how thin the steel inside is now.

I am just hopeful that getting them clean and keeping them clean and dry, and oil coating, and stored inside will prolong its life.

Oh and it needs to be used...... that will help a lot

[Johnny4428]

Mine has never had a front stay.

[gbjeppm]

Mine has never had a front stay.

Interesting on the stay. I keep looking at the pictures, and i think that my bike with the mudguard/fender with the stay extends further over the top of the tire, although I can't be sure.

When i take it off I will look for a part number, it may be after market.