Budget CB550, 'Parking Space' Build!

[Raygun]

Hey all,

I've posted a few times asking for help and parts so thought it would be worthwhile starting a build thread. Bit of background: Over some of the lockdowns I built up a Suzuki GS125, thought the project took a bit less time than I was hoping and so after chatting with my neighbour I decided to up the stakes a bit and build 2x Honda CB550 'F2's- one for each of us!

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Here is the Suzuki, recently finished and listed for sale.

I've picked up 2 engines, 2 frames, and some other not very useful parts and am slowly realising this is a much bigger project than the little Suzuki!

I've just started on a carburettor rebuild of the old PD's until I can track down some 069As to fit instead, so at least I have something. Seperately, I've started a a top end rebuild on both engines, which are heading off to Nurse Julie's for some inspection soon. (All credit to this forum for helping me arrange that)

Here is how they were when I found them
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I've taken some timelapse videos so will post up a link soon.

P.S- I'll keep updating my Parts Required thread, so if you have any parts for a CB550 that you need rid of, please let me know and I'll likely what to offer you something for them!

[Johnwebley]

Hi.

Looks like fun,

I had forgotten Suzuki did small 4 strokes

I immediately thought of the small  2strokes

Sent from my SM-A750FN using Tapatalk

[taysidedragon]

The Suzuki looks good. 👍
Good luck with the 550s, looking forward to seeing the finished article.

[Raygun]

Thanks all!

Both engines have now had their top ends stripped, now deciding on what route to go for refinishing the engines and whether I want to stomach a bottom end rebuild whilst I'm in here. Top ends going off to Nurse Julie once I box them up over the weekend.

I'm getting the engines into the stand tomorrow to flip them over and take a look again at the sump, not lying beneath the bike!

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Carbs coming apart for cleaning and rebuild

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Strip in progress!

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Apart, in the bike.

[Raygun]

I actually think one of them is a K3 not an F2. It would explain why you have a set of PD carbs.

Oddjob, I think you're right. Taking apart the second top end last night and the engine serial read CB550 'E' rather than 'F', must be where the PD carbs are from.

Another forum member has managed to locate two sets of 627B carbs which look like they will be a better solution than the PDs (From my limited research!)

[Raygun]

Next Step today, got the second engine up in the stand and flipped it over to have a look at the sump underneath.

Sump is pretty grimy! Doesn't look in awful condition but some surface rust on the primary chain and some other areas. Gear teeth seem to be in good shape.

However, found a plastic hose (?) and some crap on the oil pickup filter, so wondering whether a rebuild might be necessary. (Can anyone recommend a Honda specialist I can send these bottom ends off too for a rebuild and vapour blast?)

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The sump, full of emulsified oil when I got it off. Gross!

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And this little guy was hiding out in there, probably not a good sign.

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More crap on the oil pickup

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Primary Drive Chain and Crankshaft

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What I could see of the gearbox

[Bryanj]

I will rebuild them but i will not get involved in vapour or any other blast and/or repaint

[Raygun]

I will rebuild them but i will not get involved in vapour or any other blast and/or repaint

Hey Bryan, that could be great- thanks! I've sent you a PM.

[Raygun]

I've got a nasty feeling that something is broken inside that engine. Lots of small metal pieces in the sump along with a couple of larger pieces.

The more I look at it the more I'm inclined to agree. Full re-build for both is now firmly on the list.

[Raygun]

In actual fact I can see the damage, last picture of the strainer with the piping attached, look below that and you can see shiny metal and the remains of what I assume is the kickstart mechanism. Whether this broke first or was broken by bits coming off something else is another matter. They don’t tend to break that badly internally, splines yes. I suspect we may see a gear without it’s teeth somewhere in there or a broken selector


Yep, next picture up and you can see chips off at least 3 gears, something has certainly been flying around in there.

Bloody hell, the more you look the more you spot. Check out the crankcasing just next to the primary chain, something got crushed and spun round with the chain taking parts of the crankcasing with it.

Good spot, it's not great in there at all. Hopefully worth a rebuild rather than having to seek out a new engine!

[Raygun]

Right, lots of progress!

Both engines are now in pieces.

Top ends: gone off to Julie to be worked on and returned ready for re-assembly.

Bottom ends: in bits, off for vapour blasting this week and I'm preparing to de-rust/clean all the other parts so when the casings come back I can set about measuring up for new crank shaft bearings etc.

Whilst I've got the bottom ends apart this is my 'whilst I'm in there' list of things to replace. Does anyone have any additions?

- Con Rod Bearings
- Crankshaft Bearings
- Primary Chain
- Cam Chain
- O Rings, Bolts.

Anything else that's worth attending too?

Next up after cleaning, working out how the thing goes back together...

R

[K2-K6]

Primary drive "cush" rubbers to add on the list.

[Bryanj]

Notnecessarily shells unless worn, damaged, out of spec or you dont know where they fit

[Bryanj]

Only on one engine ken, and ive seen a lot worse with no marks on the shells, depends how good the pump screen and filter were

[Raygun]

So next update in the engine headache!

Stripped both bottom ends and took a good look, it looks OK in there, the swarf seems to have come from a gouge in the casing where the engine has presumably thrown a chain or caught something and sent it flying around the sump..

Otherwise the head studs seem properly stuck in there and even with an impact wrench and stud extractor I'm having little luck

The heads were assessed and are unfortunately in really bad shape so it looks like I'm on the lookout for new ones of those for both bikes.

A little bit stuck and a good lesson in don't buy a non-runner. At the rate this is going I could be looking for two complete engines...

I'm hoping the bottom ends can be saved- potentially I might have to send them off to someone more familiar with them as whilst I could stomach re-assembly- the measurement and repair of a lot of these parts is a little beyond my experience.

Back to square -2! Not sure on what the next steps are, I'm scouring ebay for heads and barrels that may be better.

R