Neils 1978 CB550 F2 Project - Newbie Let Loose

[Bryanj]

In the US that white plastic bit has 2 switches in it and turns the always on headlamp off before connecting the starter, this tends to make the white bit even more brittle till it crumbles to dust, somebody on us forum did 3d print some

[Oddjob]

Although you’d expect the internals to be the same, in many cases they aren’t. The starter button for instance can be either a one wire or two wire installation. The 550 uses the two wire version but many others used a one wire with the button earthing that wire and activating the starter motor. IIRC the early 500 used both versions depending on the market they were intended for.

I actually bought one of those non lighting switchgear. The wires aren’t long enough for the 550F, which have exceptionally long wires. I’m not sure if the internals are the same, never got round to checking tbh. I do have a spare 550f right hand switchgear but I’m loath to sell as it’s my just in case spare and is unique in its look.

[Neilw]

First Update

The bike is pretty clean, no major rust anywhere, but both the mudguards have pitting and some cracks, which have been masked with silver paint. I'll decide later what to do with them in the long term. I got a quote for fixing and rechroming them, but it seems steep at £480!

In any case, there are more important things to address.

My first assessment has revealed:

• RH Handle Bar switch broken - I did it trying to get it to work, but the bike wouldn't start on the button - so needs fixing/replacing.
• Most rubber parts on the bike are hard and perished, so all need replacing.
• Brake lights don't work, nor the horn, nor the lights on the clocks.
• The fuse box is damaged; will replace with a more modern unit from Hondaman.
• The saddle pan is rusted through in places and needs replacing - previous owner has bodged fibreglass to make it sturdy.
• Grab rail is missing
• The Fuel tank is completely clean inside, no rust and no liner material that I can see, so that's one less job to worry about!
• There is a small amount of paint damage on the side panels, and they lack decals, as does the tank.
• Some sketchy-looking wiring.
• THe Front brake binds a bit, back is ok, but both will need reconditioning.

Engine

The engine starts and produces white smoke. It wouldn't idle, but at least it started!

I've performed a compression test and the results aren't great.

No1 - 125 psi, then with a drop of oil in the clyinder  142.
No2 - 60 psi then 100 psi.
No3 - 66 psi then 140 psi.
No4 - 115 psi then 125 psi.


I assume i should just concentrate on checking the engine over now, before ordering more parts, so unless other's experience suggests otherwise i'll take the top end apart and have a look at the head, valves seats, pistons, bores and rings before deciding whether a rebuild of the top end will fix things or there is something more terminal. Unless of course i've missed a step!

Some general pics included.


I'll stop ordering other parts untill i know i have a decent engine,





[/list]RH Handle Bar switch broken - i did it, but bike wouldn't start on the button - so needs fixing/replacing.

[Bryanj]

Valves and seats first then pistons/bores

[Neilw]

Valves and seats first then pistons/bores

I take it that's the order I do them in? But do both while i have the top end apart?

[Bryanj]

Yes to both as when you remove the head it disturbs the base and if you dont replace gasket and O rings it may well leak later