Top end is off (mostly)

I finally had some time to get at the top end this weekend. I'm partly documenting this for anyone else who may be doing the same thing, but mostly so I'll have a record for when I put it back together. I followed the instructions contained in the shop manual.

First thing is loosen the 6 bolts holding down the breather cover (mine was already off for cleaning).

Next, remove tappet hole caps, 12 screws, and 6 bolts holding down the cylinder head cover.

View of the cylinder head block with the cylinder head cover off:


That cylinder head cover contains the rockers. There is an intake and exhaust rocker. These are the pieces that the camshaft moves and the opposite side is the tappets that govern how much movement play there is for these rockers. I will be doing a thorough examination of the rocker arms, but initially I'm seeing wear that I would expect.

Hopefully my friends over on the SOHC4 forums will let me know if they see anything unusual.

Rocker arms for cylinder 1:


Rocker arms for cylinder 2:


Rocker arms for cylinder 3:


Rocker arms for cylinder 4:



Next, there's a good bit of wrangling to get at the cylinder block. First, loosen the camchain tensioner lock nut and turn the camchain tensioner screw clockwise. There's a bit of resistance there, so push clockwise and you'll feel a bit of give. It helps if you have the cylinder head cover off so you can feel the cam chain getting loose as you turn with your opposite hand. On my engine, there was about 45 degrees of turn before it was as loose as can go.

The previous owner (PO) must have done some significant hacking on the camchain tensioner screw - it's not in great shape.

camchain tensioner screw:


After you've taken tension off the cam chain, tighten down the locknut to keep the tension off, then remove the two cam sprocket mounting bolts.

cam sprocket mounting bolts (side of cylinders 1 & 2):


cam sprocket mounting bolts (side of cyliinders 3 & 4):



Next is where it gets interesting. After you remove those bolts (bag and label them for reassembly), you basically just separate the sprocket from the camshaft. It just sits on there a little off kilter. Then you pull the chain from the sprocket. Then you pull the sprocket of the camshaft. Finally, keeping a grip on the cam chain, you pull the camshaft out from the chain. Be careful not to drop the chain since it's a bit of a pain to get it back out.

Bolts out and sprocket separated:


Cam chain off the sprocket:


Now that the camshaft and sprocket are removed, you can use a screwdriver to loop through the cam chain to keep it from falling into the engine while you perform the next steps.

First, loosen the cam tensioner mounting bolt. I took it out entirely. Again bag and label. Next, unscrew the 12 cylinder head mounting nuts and the two flange bolts. There is a specific order to this since the nuts are torqued. It basically goes in x's starting at the inside - top left (center), bottom right (center), Bottom left (center), top right (center), then the next group. Loosen the two flange bolts last. Make sure that you keep track of which of those flange bolts goes where - I market my bag with instructions.

Now that you have everything all loosened, you'll need to carefully pry up the cylinder head block and remove it in order to remove the cam chain guide and cam chain tensioner.

Cylinder head block off:


Now that you have the cylinder head block off, it's pretty easy to pull the cam chain guide. Just pull up and turn 90 degrees.

In order to get the cam chain tensioner out, you need to carefully pry up the cylinder block and then squeeze the spring a bit. It should wiggle out without much fuss now.

Finally, pull the cylinder block off. It should be loose enough now that you're broken the seal. Just carefully pull it off level - again, don't lose that cam chain.

View of the bottom end with the cylinder block off (pistons still atached):


I'll pull the pistons off tomorrow. There are essentially some circular piston clips in the bearings on the side that require a pretty small set of needle-nose pliers. Mine weren't small enough so I'll need to pick some up tomorrow.

Here are some assorted pictures of parts.

Disassembled top end except for pistons:


Head gasket:


Cam tensioner, Cam chain guide, cam sprocket:

Day 4 - Front End is Off

I found some time to have at the front end tonight. It wasn't terribly difficult, but since I'm a noob, I kept having to run back to the service manual and web sites to make sure of what I was doing. Here it is...



First, I loosened the screws that hold the collets together on the top and bottom triple trees. Once I loosened those, The forks came off relatively easy, with the help of my handy rubber mallet.

I was (and still am) trying to figure out if I want to save this front end and send it out for media blasting and powder coating - or if I'd rather just put a new front end on it entirely. I've been thinking of a springer.

In order to even send the frame out to be cleaned, which I'm planning to do after I get everything off of it, I had to take off the top triple trees. I could not figure out how to do it without risking damage to the steering stem nut.

On the right there is that nut. Apparently, Honda sells - or used to sell in the '70's - a tool specifically for that (it's in the shop manual) which is the 48mm pin spanner - Tool No. 07902-200000. But I'm not buying one - and certainly not for disassembly. I used a screwdriver and that rubber mallet (and a hammer) and gently prodded it loose. It came loose pretty easily once I broke the seal.

What's pretty cool is what's under that steering stem nut - see the next pic for the steering stem bearings.

Those bearings are all ball bearings, packed in grease and held in on the sides by the lip of that piece of the frame, and on top by the nut. -- "It's all ball bearings nowadays. Now you prepare that Fetzer valve with some 3-in-1 oil and some gauze pads, and I'm gonna need 'bout ten quarts of anti-freeze, preferably Prestone. No, no make that Quaker State." -- Good thing I read some tips in some forums though, because there's another one of those on the bottom of the steering stem. So if you're following me, use extra caution when pulling the steering stem - if you plan on reusing the bearings, you'll need all those balls. I'm considering going with a tapered bearing kit from Old Bike Barn (or the like). But even if you go with a new kit, you'll still need to save your bearings and steering stem nut so you can properly guage the height.

Here's the other side of the top triple tree with the other bearings visible:





In that picture, 1 is an important tool that I use. I got it from Sears and it's a magnetic parts holder. There's a magnet in the bottom - and it's AWESOME for applications like this. I didn't have to worry about losing all those bearings, even if they drop out, they're held in place by the magnet. 2 is the actual steering stem, and 3 is the bottom bearing.

Next I will have to figure out and spend some time separating the steering stem from the top triple tree. There's a gasket there, but I'm not sure if I just put it a vice and turn or what. More research on that! A closeup of where the stem joins the triple tree is on the left.


In addition to that step, I'm also going to spend some time going over the front end. There's a bit of rust (though it looks like surface rust) on one of the forks, and I'm guessing that I'll have to put new seals and new oil in it. This truly is a lot of work but I'm really enjoying it. I've already learned a lot - and I'm nowhere near close even to completing my disassembly. For now, the front end is laying on the ground:

Another great thing I realized is that these models of Hondas actually have a steering lock. While that's great, the key I have doesn't fit it. I read how several other folks have run into that problem during their rebuilds - so it's pretty common. I'm way lucky that at least mine wasn't locked! There's always the option of going to a dealer and getting a new lock - but I think I'll probably just end up drilling it out and going without. It's not really necessary and I could use a wheel lock if I ever go anywhere where the bike is likely to be stolen.

So why is it great that I found this out? Take a look at the wheel lock:

Do you see that ring that the lock is sitting in? It looks kind of like a can with a hole in the bottom for the lock to be exposed. The interesting thing is that for the ignition on this bike, that lock was cut length-wise. The next pic shows it to you. So now I have a precisely fit holder for the ignition that I can weld anywhere else on this bike. I've been thinking about moving it back to under the seat so it's closer to the battery. That theoretically means less wiring to run later.

And here's the current setup with the ignition location:

Well, that's it for today. I'm pretty pleased that I got a lot done.

Hopefully I'll have more to share in the coming days!

Day 3

More minor progress today - not much time so I spent a little bit cleaning up the engine block with some simple green and then drained the oil and checked the oil filter.

I smell some gas in the oil and I was reading on one of the forums that this may indicate a leak in one of the seals in the top end.

Looks like I'll probably have to rebuild it - which is fine, because I was planning to anyways, but now I think I'll have to.

Interestingly, thought the oil filter was newer (had computer inked date on it) the oil in it was like 10x dirtier than the oil I drained.

No pics yet as there's nothing really to show anyone - as soon as I'm ready to pull the engine, front end, and rear wheel I'll snap some.

Day 2 - Minor progress

I got the carbs off, most of the electric. Discovered that the engine number doesn't match the frame number. :( And neither does the other engine. I'll have some work to do when I go to get title/tags. I'll tackle that when the time comes.

Also realized that I'm going to need more tools and PLENTY of GoJo.

I'm enjoying the tear-down as it is really teaching me the different parts of the engine and how things work together.

Here's what all happened:
Removed...

• Carbs
• Footpegs
• Headlight
• Bars (though I may need to put them back on to manage moving the thing around)
• Electrics
• Brake bar
• Kick-starter

Left to do - pull the chain off the sprockets, pull the front end off, pull the engine out and clean/polish.

CB550 Bobber build - day one

I bought a Honda CB550 from a guy here in town. He had already welded on a hard tail.

I should probably say that I'm a complete noob when it comes to building motorcycles, but it's something I've always wanted to try.

JB took out the trailer and helped me haul it home - worked out great because he got to practice backing up with it. I filled up most of his gas tank and bought him lunch to thank him.

Anyways, here are the "before" pics...







If anyone out there has any helpful advice or wants to come lend me expertise on this build, email me at ewendkos -at- gmail -dot- com