CB550F

[Grewth]

I'm considering taking on a 550F project after making the mistake of selling the last one in 1999.
I'm pretty clued up on SOHC 750's now, but I've forgotten most of what I learned about the 550.
So could someone with the requisite wisdom please give me some clues on what's likely to be missing or broken on these bikes.
I seem to remember issues with rear brake drums and fracture prone top yokes (or was that the 500 ?)
Not sure about the above really,  but I'd like to know exactly what I should be looking at when considering a project bike

[Sesman]

Hi, Gareth.

Which model year? I can only advise on my experience with a 1977 F2, which I sourced from America in complete low mileage condition, minus indicators and seat. Indicator head lamp ears were the biggest headache as they are becoming very rare indeed, along with original seat bases.

[Bryanj]

Brake drum yes, they can crack, top yoke was 500 and 750.
Ignition switches can be troublesome and there are about 95 different sets of wiring!.
Ocassional gear breakage but not common, cam cover wear is heard of

[Grewth]

Many thanks,  both of you  !
I think that the pile of bits I'm looking at is a combination of F1 and F2 bits.
Maybe some late 550K, but nothing early.
Brake drums I don't think there is any engineering solution to,  except to keep buying them until you find a good one.
Not heard of a successful re-lining as of yet.
My 550F1 had aftermarket cast alloys, can't remember the make, Italian I think.
Thanks for the heads up about the headlamp mounts - hopefully someone will start making replicas soon.
I think my F1 had a replica seat with a GRP base, and that was 30 years ago.
Ignition switch  ?
Don't  David Silver Spares  sell a decent pattern copy quite cheaply  ?

[Bryanj]

Yes you can reline the drum, just have to find a man with a lathe

[Sesman]

Yes, the pattern ignition switches are just fine. Other potential failure points are the RH switchgear starter button, which can turn to goo and disintegrate.

[Murf]

The 550 I am restoring is a 75 K1 so earlier than the one you are looking at, it was also a very neglected US bike that had probably been sourced from a scrap yard, then badly bodged by its UK PO to get it back on the road.  Luckily I think it had come from a dry climate area so rust has not been a big problem and most of the chrome has survived relatively well and wheels, mudguards, headlight ears are all usable. Looking at the quality of the chrome, which is 50 years old, I am sure we will never see chrome of this quality ever again.
So bad bits:- worn fork stanchions, knackered rocker cover, knackered cam shaft, knackered cam chain tensioner, stretched primary chain (no chain tensioner on these bikes. Leaking oil pump, needs new o rings, most oil seals on engine leaking, complete top end overhaul needed, carb rebuild needed, new wheel bearings and seals, new swinging arm bearings and collar, new brake hoses. New rear brake shoes, repairs to rusted out seat base, new seat cover, repaint frame, battery box and swinging arm, new fuse box, repair and or replacement electrical components. Wrong Speedo and rev counter fitted, check this as good ones are getting harder to find at a reasonable price.

Well  the list just goes on and on and I haven’t opened up the bottom of the engine yet. 
Neglected 550s can have a lot of problems however they are nice bikes to work on and I am sort of enjoying doing it, but I would rather be riding it😁.

So if you want a project and fancy a lot of work and spending a lot of money buy a crappy bike. If you want a bike to ride next spring and save some cash buy the best 550 you can find.
Good luck

[florence]

When I bought my 1974 500/4 in boxes for £150 in 1995, I found the more I stripped the engine, the more problems I found.  Basically, it was worn out, probably from lack of regular oil changes by previous owners.  The camshaft and rockers were scored badly, bores very worn, even the crankshaft was out of tolerance.

Luckily, I managed to find a really excellent low mileage engine from DK Spares for £350.  They actually sent two, the first one I stripped the top end and found it was not in great condition so sent it back.  The second one was found to be excellent though.  I was told it had only done 7K miles.  Being quite particular, and as I had the spares already, I fitted a new cam chain and tensioner, rebored my spare barrel, fitted new pistons and rings and have been running this ever since, changing the oil and filter every 1000 miles.  I am convinced this makes an enormous difference.  It has been a very cheap bike and now the clutch works properly, I love it.  Great fun to ride, even goes round corners reasonably well, although hoping to upgrade the rear shocks soon.

[DomP]

Ken gave me the number of a bloke in south Wales that can reline brake hubs, i can dig it out unless he pops up with it

[Grewth]

Yes you can reline the drum, just have to find a man with a lathe

Thanks for that,  I've obviously been mis-informed.

[Grewth]

Ken gave me the number of a bloke in south Wales that can reline brake hubs, i can dig it out unless he pops up with it

Many thanks also.
Hopefully I'll not be needing that service, but I'll bear it in mind for the future.
Apparently,  the classic Suzuki T500 suffers similar issues, but on the TLS front drum.
I was reading about one  owner who re-lined his front drum ( he was an engineer apparently ), but unfortunately the drum later shattered while he was riding the bike.
Nice !
Maybe he went too far on the interference fit ?
Anyway,  that story sort of put me off the idea of re-lining motorcycle brake drums.
But if someone can successfully re-line the CB550 drum, I'm quite happy to accept that, and I may indeed resort to that solution myself if required.

[Murf]

If the pile of bits you are looking at is reasonably priced they might be worth a punt but I tend to find people have an inflated idea of what knackered old bikes or boxes of bits are worth. I guess it’s the parts value. However good or restored bikes seem to be reasonably priced, particularly when you consider the high cost of parts and restoring a bike. 

Of course there is great satisfaction in taking a pile of bits or a knackered bike and turning them into a nice usable reliable bike that people comment on.  Also if you want to do something a bit different then buying a pile of parts can be the way to go as you aren’t constrained by the guilt originality.

[Bryanj]

If you buy it i will give you an incomplete bike for scrap value located in Gloucester

[Grewth]

If the pile of bits you are looking at is reasonably priced they might be worth a punt but I tend to find people have an inflated idea of what knackered old bikes or boxes of bits are worth. I guess it’s the parts value. However good or restored bikes seem to be reasonably priced, particularly when you consider the high cost of parts and restoring a bike. 

Of course there is great satisfaction in taking a pile of bits or a knackered bike and turning them into a nice usable reliable bike that people comment on.  Also if you want to do something a bit different then buying a pile of parts can be the way to go as you aren’t constrained by the guilt originality.

My technique is usually to keep buying abandoned projects cheaply,  until I have enough good bits to build a complete bike.
I then assemble a big pile of damaged and worn out parts, and sell them on as an abandoned project to some unsuspecting victim.
Seems to be working with my CB750F1 project.
If I come across someone who wants an extortionate price for their sorry looking pile of rusty bits,  I just walk away.
Maybe leaving my phone number before walking.
The sticking point with this abandoned project would seem to be the complete 550F engine which is not in the frame.
Yes,  it's not seized,  but that doesn't mean that it's not completely worn out,  bad head ? bad cam ? bad crank ?
Anyway the present owner seems to think that the engine alone is worth a truckload of money.
The rest of the remaining bits. Less so.
I might just try to persuade him to sell me just the rolling chassis.
Dunno yet.

[Grewth]

If you buy it i will give you an incomplete bike for scrap value located in Gloucester

Thanks for the offer !
It might take me a couple of weeks yet to sort out this prospective purchase.
I'm in two minds about it at present.
I'll see what sort of deal I can thrash out with the seller