Topic: CB550 Rebuild, Phase #1, The engine - EDIT: Now a 650!

[canttuckmyshirt]

I have a few weeks between jobs, so I figured a restoration would keep me busy.
I'm starting with the engine.

1977 CB 550.

The bike came off of craigslist as a load of parts. So far a lot of things look clean and virgin.

Almost done with disassembly.








I noticed cylinder #1 and #4 look different. The head looks "cacked" on one and "oily" on the other. Could this be a bad seal somewhere? Valve guide?





sleeves don't look bad.



Cams look discolored a bit. I havent even wiped them off.No serious marring.









Sadly I lost the order of the pistons when removing them.


My parts and to-do list. Please chime in:
Full soda blast and degrease
Full powder coat
New primary chain
Full gasket set
Port match intake manifold to head
Hone sleeves
New rings

Anything else I should do while I'm in here? Trying to keep this on a bit of a budget. Powdercoating was important to me as want this bike to be a little flashy.

This is my first "rebuild". I've read the manual, but otherwise I'm winging it. Plan on stopping by a machine shop on my way to work tomorrow to show them what I'm up to.

[minimo]

Awesome!

Upon reassembly, please don't forget to install the bearing set rings before you button up the lower case...


#1 - 13491-283-000 RING, BEARING SET, 57MM
#2 - 13492-283-000 RING, BEARING SET, 52MM


Find out what happens when you omit these small parts... http://forums.sohc4.net/index.php/topic,115122.550.html

[canttuckmyshirt]

I appreciate the response! I have everything on cardboard templates. I am OCD enough to keep them all labeled and in order.

[minimo]

Great!

[flatlander]

make pictures of everything as you disassemble it, in phases. it will help you immensely later.

[MickB]

Make sure you put the RH oil deal on the crank before you close the cases and make sure it sits in the groove.

[canttuckmyshirt]

Still cleaning and soda blasting parts. The head and jugs are still soaking.

Do these cam journals on the head look horrible?







I am waiting for a delivery of plastigauge. Any input on the visual of the crank bearings?







I also found a broken fin on the front of the cylinder housing. Broke my heart

[canttuckmyshirt]

I also wanted to add that there was no marks from the primary chain hitting the lower case. There was about 3/8" of total up/down slack. Should I reuse it? I was all out to replace everything, but reality is kicking in and I want to keep it on a budget. I only split the case to powedercoat it. I want something showy, as I don't plan on riding this particular bike a ton.

P.S. this motor was bought as-is and the PO had no clue if it had any issues. Mileage is unknown but assumes to be around 12K. The bike it came out of was obviously dropped on the left side.

[CBGhia]

Damn Cal.....

But to his point, if you have already split the cases, replace the primary chain and the cam chain.  Why risk either breaking later if you already have it apart?

[canttuckmyshirt]

Cal, believe it or not, I like your style

Point taken. I hate half assed things myself. This is my first motor build and would love to not leave an oil tattoo on every parking space I occupy. I'm just not totally clear on what needs replacing and what should be inspected and reused.

I have no plan on "showing" the bike. I just want a project to keep my hands and mind busy during my down time from work and a full build sounded like fun. It would be devastating to my ego if I dove this deep and came back with a leaky pig of an engine that doesn't run well.

[SOHC4 Cafe Racer Fan]

If the cases are split, you have to have rocks in your head not to replace the primary chain and cam chain.  It's called peace of mind -- to you and a future owner.  Even is this bike is a trailer queen, how would you like your primary or cam chains to fail on your Sunday ride.  You'd be kicking your own ass the whole walk home.

I can see the desire to make a pretty bike.  Just make it a reliable runner, too.  Otherwise, don't rebuild the motor at all -- just paint it and keep the bike as a non-running, pretty sculpture.

[SOHC4 Cafe Racer Fan]

Are you still going to put all kinds of money into this engine or buy that 650 motor (the price includes a bike that will recoup your money -- so free motor!)??

[canttuckmyshirt]

So I bought the 650 engine. The seller said the PO claimed it was "rebuilt".
The cases look like they have not been opened. Definitely poorly painted over.

We first notice that the exhaust stud threads are all destroyed.





Oil filter housing is chipped up



The rocker cover was dropped or hit with a grinder. Not sure.



The starter has been messed with



Wiring needs attention



And some head fins are broken



These observations helped a lot with negotiating, BTW

As with all new toys, the first thing we do is open them up.

Oh, something is broken in the rocker cover. No surprise.



Alas, the story does hold some truth. The pistons look clean and the gaskets look new.



The chambers look cleaned.







And I think I see fresh-ish honing marks on the cylinders.




So It looks like I would need new gaskets, jugs, head (housing only), and possibly rocker cover. I'm pretty torn. On the lighter side, the cam looks good.

[canttuckmyshirt]

Would the 650 carb, 79-80 no CV, benefit my 550?

[bwaller]

Wow that head is a mess because of those exhaust studs.

[SOHC4 Cafe Racer Fan]

I got a spare 650 motor, but it would be a biyatch to ship it.  Plus, the cam and tach drive are promised to another (but you have those parts). 

I would stick with the 650 motor.  You can get a set of jugs.  As for the head, I would advise sourcing a 79 or 80.  Then you can have the option of using 750 carbs.

Some of these flaws could have been spotted before your purchase (broken fins) and possibly the exhaust studs.  Make sure to look parts over super-carefully beforehand.

[flatlander]

that poor engine has been treated like crap, by someone who has absolutely no clue or respect for mechanical things. make sure you check and double check everything before you trust it.
hope the guy paid you to carry it off 

[canttuckmyshirt]

The engine cost me a lot less than what the cam alone would have cost.

Making progress...

I sourced another head (81-82), cylinders, and rocker cover. The machine shop decked the head, honed the cylinders, and cut and lapped the valves. A broken bolt was removed. I am blessed to have such a good local shop!

Waiting on gaskets and SS bolts to arrive.

ZX600A carb is also in route.



The head gasket surface is actually super well machined. I took this picture after machining, but before cleaning the baking soda off from soda blasting.

Next week I will transfer all the rocker parts to the new rocker cover.

I need to get my LS1 off the engine stand to we can prep for assembly.

[SOHC4 Cafe Racer Fan]

Nice!  Yes, it's great to have local, high-quality machining services.  It sure helps avoid delays. It sounds like you should have the engine assembled in short order!

[flatlander]

this is starting to look promising

[canttuckmyshirt]

ZX600 A carbs came in. These where a steal on eBay and in great condition. People must have been snoozing when I found this deal.

[Stev-o]

... then you might as well wad up what cash you have, wipe your butt with it, and flush it down the toilet.

HA! You dont need to sugar coat it, Cal!

[SOHC4 Cafe Racer Fan]

Very nice!

Which year ZX600A carburetors are a direct fit for the 81-82 head?

[SOHC4 Cafe Racer Fan]

ZX600 A carbs came in. These where a steal on eBay and in great condition. People must have been snoozing when I found this deal.

Yeah, you stole those for $120.

[canttuckmyshirt]

Very nice!

Which year ZX600A carburetors are a direct fit for the 81-82 head?

85-87. I'm going to test fit in Monday, but this is per other posts on this forum.