Author Topic: CB550 Rebuild, Phase #1, The engine - EDIT: Now a 650! (Read 4643 times)

canttuckmyshirt · « **on:** March 01, 2016, 05:40:11 PM »

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 · « **Reply #1 on:** March 01, 2016, 05:48:22 PM »

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 · « **Reply #2 on:** March 01, 2016, 06:00:01 PM »

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

minimo · « **Reply #3 on:** March 01, 2016, 08:22:48 PM »

Great!

calj737 · « **Reply #4 on:** March 02, 2016, 03:56:19 AM »

Also replace your cam chain, it will likely need it by now. I mic the valve guides, and verify the cylinder specs before deciding on rings. If beyond wear, new pistons and rings are in order. And new valves seals are probably a good investment too.

Also encourage you to rebuild the oil pump using one of Elan's (he's a member here and has a Parts/Services thread) oil pump kits. He provides the unavailable O-rings you need.

flatlander · « **Reply #5 on:** March 02, 2016, 05:22:01 AM »

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

MickB · « **Reply #6 on:** March 03, 2016, 04:59:56 PM »

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 · « **Reply #7 on:** March 23, 2016, 06:48:10 AM »

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 · « **Reply #8 on:** March 23, 2016, 06:53:58 AM »

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.

calj737 · « **Reply #9 on:** March 23, 2016, 07:49:35 AM »

You're building a bike for "All Show, Maybe Go"? That strikes me as a complete waste of time and money. Allow me to pontificate...

If you believe that you will, on your own, build an award-winning bike to rival the professionals who build for "shows", then I hate to burst your bubble. If you are re-building a bike that will be an occasional rider, then build it properly, one time for your own safety and reliability, and that of a future owner. A Primary Chain is inexpensive, but invaluable. If you embark on taking short cuts now, on such critical components, then you might as well wad up what cash you have, wipe your butt with it, and flush it down the toilet. It will save you on hand soap going forward.

I don't mean to be harsh, but there are literally thousands of threads here and elsewhere of, "Started, couldn't finish, pay me what I spent...". The reality is that everyone of these would-be project builders loses 90% of his spend. If that's a palatable return for you, please feel free to powder coat it, button it up, and bling on. Don't worry that it won't run right, will clunk, clank, and smoke and bleed oil as if it were struck by a .50 in the pan. Nobody will notice for how "stunning and innovative" your backyard build is...

Just makes sure to tote some cat litter to spread beneath your bike when you park it outside the bar or cafe so as not to taint our environment with motor please.

CBGhia · « **Reply #10 on:** March 23, 2016, 08:10:23 AM »

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 · « **Reply #11 on:** March 23, 2016, 08:27:19 AM »

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 · « **Reply #12 on:** March 23, 2016, 08:31:43 AM »

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 · « **Reply #13 on:** March 23, 2016, 08:50:29 AM »

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 · « **Reply #14 on:** March 25, 2016, 02:32:26 PM »

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.

calj737 · « **Reply #15 on:** March 25, 2016, 03:04:05 PM »

Bad luck about the 650 motor...

if the cam and rockers are good, keep them oriented for installation in your 550 motor. And keep track of the 550 can sprocket and sprocket bolts. The 650 tach gear is different to the 550, so you'll need to swap to a 650 or 750 tach for accurate readings (or go electronic). The cam chain sprocket for the 650 is different than the 550 which is why you want to use 550 sprocket with the 650 cam.

canttuckmyshirt · « **Reply #16 on:** March 25, 2016, 03:27:38 PM »

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

bwaller · « **Reply #17 on:** March 25, 2016, 07:11:34 PM »

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

SOHC4 Cafe Racer Fan · « **Reply #18 on:** March 25, 2016, 10:03:50 PM »

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 · « **Reply #19 on:** March 28, 2016, 12:31:14 PM »

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 · « **Reply #20 on:** April 08, 2016, 04:24:18 AM »

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 · « **Reply #21 on:** April 08, 2016, 08:31:46 AM »

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 · « **Reply #22 on:** April 08, 2016, 12:11:57 PM »

this is starting to look promising

canttuckmyshirt · « **Reply #23 on:** April 09, 2016, 12:02:50 PM »

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 · « **Reply #24 on:** April 09, 2016, 12:13:33 PM »

Quote from: calj737 on March 23, 2016, 07:49:35 AM

... 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 · « **Reply #25 on:** April 09, 2016, 02:03:07 PM »

Very nice!

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

SOHC4 Cafe Racer Fan · « **Reply #26 on:** April 09, 2016, 02:08:13 PM »

Quote from: canttuckmyshirt on April 09, 2016, 12:02:50 PM

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 · « **Reply #27 on:** April 09, 2016, 02:26:32 PM »

Quote from: CB750 Cafe Racer Fan on April 09, 2016, 02:03:07 PM

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.

News:

Author Topic: CB550 Rebuild, Phase #1, The engine - EDIT: Now a 650! (Read 4643 times)