Topic: 1975 CB550 K Rebuild & Small Mods from AUS

[Bootsey]

Polished the ring lands with some fine steel wool, then the cylinders got blown out, washed with warm, soapy water, and wiped clean with a white rag. Lastly they got a light coat of oil.
Did one last check to make sure all the piston rings were the right way up.
I bought a Vesrah full gasket and o-ring kit. Installed new base gasket, with a light coat of oil. Installed new oil feed o-rings and outer sleeve o-rings, and made sure they seated down into the recess.



Next up I installed the cylinders. Made sure to space the rings gaps about 120 degrees apart.
These cylinders have been bored and honed to 59mm, to suit the CB500 +3mm pistons that have been installed. It was a little while ago that I got the cylinders bored, but from memory I think the machinist setup a bore to piston clearance of either 0.0010 or 0.0015". 

Installed a new cam chain guide. I also have a new cam chain tensioner blade to install. Does anyone happen to know if there is a specific orientation at which these go into the tensioner assembly? One end seems to have more of a bend, but I can't remember which way the old one was in, as I've had it out, and didn't check...
Cheers

[dave500]

those pistons?you ran a 1mm drill bit through the oiling holes behind the oil ring assembly?you WILL get crud out of them,i like to slightly chamfer them aswell.

[Bootsey]

The pistons were NOS, no crud to clean up. Did check all the oiling holes were free of any castings etc.
I've got to a bit of work cleaning up the head. Did I read you chamfer the oil passages on the head, where it mates with the top of the cylinders?

[dave500]

ok cool I haven't looked back through this thread re pistons,yeah I like to also chamfer the heads two end oilways,i think its the thought that counts?

[Bootsey]

I probably forgot to mention what the pistons were...
I bought a CB500 Bigbore Kit +3mm, so 59mm, which works out to be +0.5mm on the stock 550 bore. Came with pistons, pins, clips and rings.
Whats the reason for the chamfer? Help with the faces mating?
You ever used this stuff before?

[dave500]

I chamfer the heads oilway entries as its a bit of a step down in size from the barrel oilway outlet,that way the flow doesent smack into a square edged slight reduction but sees a sort of funnel?yeah I use that lanolin,its good stuff.

[Bootsey]

Awesome, thanks Dave, makes sense to me.

[Bootsey]

Pulled the oil pump apart, had to mount it back on the motor to get the countersunk cover screws undone.
I'm not sure if someone has had this apart before me, the manual says that the punch marks on the inner and outer bodies should both be upwards, but the punch mark on the outer ring was downwards...Not sure if that means much.

All the o-rings look good, no cracks or tears, still soft. Should I replace these anyway?
All the clearances are good. There's some tarnishing on the pump bodies, though are smooth to touch, this normal?
Also the relief valve seems to be stuck, how does one go about unsticking it? Got it out with a magnet



Got around to taking the valves out of the head. They all came out easily, and spun smoothly in the guides, so I'm assuming this is a good indication they aren't bent.
Next I'm going to clean up the ports, remove all the carbon, and smooth out any casting marks. Found some brilliant threads on doing this.
Clean up the combustion chambers, try to tidy up the spark plug thread on #4, lap the valves, new valve seals, and hopefully it should be sorted.

[Bootsey]

Progress has been slow and steady, whilst I waited for a few bits and pieces to come in the mail.

Started cleaning up the head, decided to do a little work on the ports. Exhausts ports got a clean, and some smoothing out of the casting marks around the valve stem guide boss.


Didn't reach touch the intake side, other than to smooth out some very obvious casting marks, and to match the intake runners.



The valves were pretty crusty, the exhausts in particular. Soaked them in diesel, then cleaned them up with the brass wire wheel on the bench grinder. The faces and the seats in the head looked OK, so I gave them a light lapping. Just enough that they had a clean, even ring, then reinstalled them, and checked they didn't leak, with some kerosene. All good.
Slightly chamfered the oil feel holes too.



I purchased a 650 camshaft to drop in, off another member. Checked it fitted, and didn't foul anywhere. Also got a used set of CB500 rockers & shafts, as a couple of my rockers were pitted. They were cheap, and I thought it would be good to fit the longer shafts, to hopefully negate any future wear of the rocker cover.


Then, whipped the valves out, washed the head in warm soapy water, dry it off, oiled the seats, and painted the head.
Reintalled the shims, new valve stem seals, and the valves. Gave them a whack with a plastic mallet&cloth, to make sure they were seated.
Head gasket got a light coat of Permatex Copper seal, installed new o-rings, and installed the head. Torqued it down, will probably back it off and re-torque again tomorrow. Starting to resemble a motor again...

[goldarrow]

Just double checking to make sure when you tried and fitted the camshaft. Fit it on the head and spin it, fit it on the cover and spin it.  If no clearance issue, should be good to go

[Bootsey]

Thanks Goldarrow, yep, checked it fitted in the head, and in the cover with the new rocker arms. All was OK!

[dave500]

might've caught you a bit late?have a look how the manifolds match up to the head,you can improve them a lot some times.

[Bootsey]

Hey Dave, thanks for the heads up. All good, yeah I matched the intake ports to the intake runners, there's a couple of photos above, albeit #$%*ty quality photos.

Hows this swingarm collar look, in need of replacing? I've already given it a bit of a clean with the wire wheel.
Its a bit pitted, and I mangled one end a little getting it out, but I reckon that end could be welded and turned back to size in no time. Or should I just get a new one?

[dave500]

yeah derr I just saw you matched them up!good job,thats all they need no trying to open them up or anything,see how a new bush fits the collar?a new collar is about 50 pounds!hundred odd bucks without postage!while you have the main bolt out piss of those weird jap grease tits and tap for you beut normal aussie ones,or is yours in the actual swing arm with none in the bolt?

[Bootsey]

So I torqued the head down, let it sit overnight, then the next day, backed off the nuts, and retorqued to 16 Ft/Lbs.
Applied a very light smear of sealant, and fitted the 6 pucks. Also put a dab on the top tensioner mount bolt.

Next up I need to clean up the advancer, and then install the 650 cam. I've found multiple threads with this process explained, so here's hoping I can get it done.

Going to do a parts order, wanted to see if anyone had any thoughts on the following

- Planning to grab a kit with new points and condensers.
-Drive chain - 530 ? Any particular brand?
- Spark plug boots, they are the original, with no markings - Replace them straight up I imagine? 5kΩ or 10kΩ
- I imagine its a good idea to replace all cables? 2 x throttle, clutch and rear brake?
- Haven't found anywhere to buy swingarm brass bushings? There were some on eBay until recently but they've all disappeared...
-The bike was missing the starter solenoid when I got it, any particular suggestions?
-Planning to change the fuses over to ATC/blade style. Any old fuse block do the job?
-Any other suggested upgrades/investigations on the electrical system?

Cheers

[Bootsey]

Had to clean up the advancer, the bike had sat without a point cover for some time, so it was worse for wear.


Luckily, for me atleast, the topic of installing and timing camshafts has been done to death. #$%* I hope I got it right after saying that.....
Installed the advancer. Put the cam in through the chain first, chain on the left side of the mounting flange. Then fed the sprocket on, and used the mickey mouse ears on the sprocket to get enough wiggle room.

Set the cam to the timing mark for 1&4, and checked with a pencil that it was at TDC.

Rotated the cam so that the slot was parallel to the head, and facing forward.

Rotated the crank 360, so that the T for 1&4 was lined up again. The slot in the cam was parallel and to the rear. So I'm thinking I'm good to go there?


Cleaned up the front sprocket. Should I add a dab of loctite to the sprocket bolts?

[dave500]

you got the cam spot on,did you dissemble the advancer unit to clean it?

[Bootsey]

Awesome, cheers Dave.
Yeah, pulled it apart and took to it with a brass wire wheel in the drill, and that's as clean as it get. It's not pretty, but it operates smoothly.
Any thoughts on those parts I listed above?

[dave500]

did you make sure you put that cam barrel back on the right way,that you can get 180 out,heres the index marks the dot or scribe can be hard to see.

use any solenoid that will fit/work from anything,same for the fuse block,jaycar do automotive stuff aswell,rk/ek heavy duty chain is fine,did if you want better did perhaps?you know not to use o ring type on the 500/550s?5kohm caps will work fine aswell.

[Bootsey]

Ah, thanks for the heads up, I had missed that, I'll double check.
I'd read a bit about the o-ring chains, so will be stearing clear. Thanks again mate

[Bootsey]

Another couple of questions for you Dave if thats OK, a penny for your thoughts...I think I'd owe you a few pennies by now

Did you have to change your gauges from MPH to KPH? If so, how? Just a different face decal?

I've been thinking about running a digital speedo/tach, that would solve my conversion issues, and mean I wouldn't have to find a tach to suit the 650 camshaft. This means I'd have to go to an electronic ignition for the gauge I'm looking at using. Do you run electronic ignition? Worthwhile upgrade? I've read a few pros and cons about improved general running, but difficulty in quick fixes and issues with run down batteries...

[dave500]

mine was already k/ph speedo,i run a boyer electronic,ive had a few on these bikes.

[Bootsey]

Have you got upgraded coils or stock?

[trueblue]

This is where I make Dave jealous again.  I have Speedhut electronic guages on my 650, they are probably the best thing I have added to the bike.  They work great and look even better, the only issue is they were a little costly, but not too bad.

[dave500]

ive always like that setup of yours Andrew,its done bloody well!a lot neater and easy to read than most of the gauges available with too many functions,i have different coils that come with the boyer unit bootsey,these are wired series,all plugs fire at once,they also do a unit that runs the stock coils,ive used those aswell they work fine,they also fire all four at once.