Topic: Cb550k The "learning" motor (is un-stuck!)

[kerryb]

BC 21418 flex hone on ebay is what i want to buy but shipping to UK is too expensive

Ok, more learning via stupid questions.
I looked up the hone listed above, it measures 57.15mm.  The std bore of a cb550 cylinder is 58.5 up to 58.6mm

And here's the dumb question;  does the hone need to be bigger than the desired finished size to exert pressure on the cylinder walls for cutting to take place.  If so, how much bigger than the starting or final bore?

[minimo]

The 2 3/8" 60mm Engine Cylinder Flex-Hone 180 grit worked for my 1977 CB550F. I also drenched it in the honing oil and did my best to make quick and consistent strokes to etch a nice and even 45-degree crosshatch.


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[kerryb]

The 2 3/8" 60mm Engine Cylinder Flex-Hone 180 grit worked for my 1977 CB550F. I also drenched it in the honing oil and did my best to make quick and consistent strokes to etch a nice and even 45-degree crosshatch.

Ok, that makes more sense to me. Now I have a starting point, I always learn better by doing.
Thanks.

[bryanj]

I may have quoted the wrong number but same seller does several sizes and i was working on 500 anyway

[kerryb]

I may have quoted the wrong number but same seller does several sizes and i was working on 500 anyway

That's what I suspected, but I was working from a lack of knowledge.  Thanks.  I did go to their website and found the other sizes.

[kerryb]

It is settled then, this engine is not on my list of rebuildable motors.  Too much money for the expected returns.  With that in mind I have a few question.  But first, the place we're at;
1. Made a caveman boring tool to clean out cylinder #4 ( wood, foam, and sandpaper)  almost clear enough.
2. Re-assembled all engine parts in correct position to practice order of operations ( pretty sure forward cam chain guide is upside down, need to check)
3.  Planning some fixtures to hold parts to ease cam chain installation..."what a cluster".
4.realize that without an advancer and points plate, crankshaft orientation is a guess.  Do I just put 1-4 at TDC as measured with a stick through the spark plug hole?
        I found the cam chain install post in the FAQ, and I think it answered all those questions, I'll know for sure on the next try.  ( still can't rotate crank through a full circle, but is better.)

Parts wanted;  clutch basket and friction parts for a '75 cb550k.  These would be the ones in your scrap pile...not suitable for road use, but still work well enough to practice assembly procedures.  I will assemble/dis-assemble this engine enough times to not need research breaks.  So these parts are only worth a few bucks plus shipping.

[minimo]

I like this idea of the “learning motor” - it makes a lot of sense and it is good to feel carefree about digging into things and then getting a feel about how to put the parts back for the real thing.

I have had to learn via making dumb mistakes on my only motor. Whether it was accidentally leaving out some parts or fixing seals, etc. Nevertheless, it’s always a learning experience. The “roadside mechanic” experiences are also huge for picking up some ideas. But it’s good to keep those to a minimum unless you love living on the edge, so to speak.


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[kerryb]

yeah...I was glad I made the decision after I put the cam, chain, and pulley together in the wrong order three times!  I finally got it but not without several possible nicks to the can journals (bearings) in the process.  Put it all back together knowing it's going to come apart again to get the cam timing right.  ( not even close right now).
I looked at those pictures and read the descriptions many times but it wasn't clicking.  Read the FAQ's this morning and it makes perfect sense!  There is a really good description in there that doesn't even need a picture.

[Redline it]

I bought a '75 550 motor to practice on.  I didn't want to "learn" (break stuff) on the 550 motor in my new '78 project bike because it runs!  So I brought home a motor to practice assembly/ disassembly procedures on.

smart move, plus you get a bunch of extra parts. some of these post are heartbreaking on the forum when a guy picks up a bike that the original owner says it only needs "this much" to get it going. and the buyer doesn't have any experience at all in rebuilding these relics, then goes the route of boring, valve job, the works and the bike runs for 5 miles and seizes. it takes me 2 or 3 times of practicing and i still don't get it right.

[kerryb]

I bought a '75 550 motor to practice on.  I didn't want to "learn" (break stuff) on the 550 motor in my new '78 project bike because it runs!  So I brought home a motor to practice assembly/ disassembly procedures on.

smart move, plus you get a bunch of extra parts. some of these post are heartbreaking on the forum when a guy picks up a bike that the original owner says it only needs "this much" to get it going. and the buyer doesn't have any experience at all in rebuilding these relics, then goes the route of boring, valve job, the works and the bike runs for 5 miles and seizes. it takes me 2 or 3 times of practicing and i still don't get it right.
[/]quote
You got that right,  I 'm working up to an engine overhaul slowly.  I'm pretty good at rebuilding breaks and forks, and carbs so far.  Had success with timing, head gaskets, valve replacement and water pumps (goldwing), but an actual engine overhaul is a little more nerve wracking.  But it gets better, talking with my buddy about this project and he says we could set up his boring machine and figure out how to bore the cylinders for new pistons!  He likes to collect vintage machinery and refurbish it...the lathe in his workshop is 12 feet long! 

Does cruzin image make a piston kit for the 550?

[kerryb]

I made a sanding attachment for the drill to clean enough rust out of the cylinder for the piston to slide up and down.  Remember...I bought this motor to practice assembly/disassembly.  after 4 or 5 tries, everything is back together in its proper position and playing nice with each other.  I wanted to practice setting valve lash on this one but didn't know which cylinder was ready to fire next because all the adjusters were loose.  So I took the cover off and reset the engine to cyl #1 at tdc and the cam lobes facing down.  Put the cover back on and set the valves in firing order.
So here's the puzzle:  with the adjusters all backed off, I couldn't just wiggle them to see who was in firing position.  Would it have worked just as well to see who moved and go to the next tdc after the intake valve closed?  I wouldn't want to take apart the actual motor build after assembly like that.
I had to make a very crude degree wheel to take the place of the missing ignition plate and advancer!

[bryanj]

Pick either 1 or 4 and hold up the adjuster ends of the rockers on that cylinder, when the inlet starts going down and the exhaust is nearly all way at top the cylinder is on tdc of exhaust stroke so you adjust the valves of the other cylinder.
You can then reverse procedure for opposite firing cylinder then start again with 2 and 3

[kerryb]

That makes better sense, Thanks.

[1976cb750f836]

I like this idea of the “learning motor” - it makes a lot of sense and it is good to feel carefree about digging into things and then

79 and 80, I went to NADC , auto,  diesel, college in Nashville. That's exactly what we did. I remember a turbo 400 transmission,  for 8 days straight, we (a team of 2), tore it completely down , then after teacher inspection, reassembled , by the 8th day we could do it 3 times.
Then 1 day of classroom book study. Nothing like Hands on learning. 1 instructor I had made a comment I still to this day use, he said, all u have to do to be a good mechanic is , have a good memory, and put stuff back like u find it!

[bryanj]

Not always as some numpty could have been there first ans assembled it wrong!

[1976cb750f836]

Not always as some numpty could have been there first ans assembled it wrong!

Yes, benn their, seen that!