Topic: Call me Crazy Build CB550

[lightsareout]

I've been wanting to get a bike for a long time now and was recently inspired by Dino's (Hack a week) 750 build.  I enjoy working in the garage on different projects and when I start a project of what ever kind I dive in and learn everything I possible can about the subject. 

Browsing on Craigslist I found a 78 CB550 that is in pretty rough shape (lots of parts missing) and the seller said the engine is seized.  It was last running 5 years ago the PO told me and he had owned it for 12 years.  For $200 I decided to take the gamble and went and got it. 

Its really a blank canvas for me to make my own which I'm excited about.  Right now I'm thinking of building it into a stripped down cafe racer style. 

First on my list is to get into the motor and figure out what is going on.  Yesterday I pulled off the exhaust and pulled the plugs.  Cylinder 1 was full of fluid - the rest didn't look all that bad. What I'm thinking is since the carbs were pulled off the intake valve was open on #1 allowing it to fill with water while it sat in this guys yard.  The kick start has some travel before stopping; around 2" downward motion.  I blew all the liquid out and sprayed some PB blaster down into each cylinder.

Is it possible the PO when checking if the engine was free really put some weight into the kick starter and broke some of the internals with the hydro locked cylinder?

Lastly I pulled the oil drain and it did have oil in it.  It was a thickish sludge with some milky streaking but not nearly as bad as I was expecting.  I hope to get the motor pulled out this week and get the head off to better assess the motor.  Hopefully Its not too far gone and can be rebuilt.

One thing I noticed is the frame has the correct 78 sticker and serial number, the serial on the top of the engine case is a 78 but when I took the oil filter off someone had wrote "76" - Thinking someone rebuilt this was a 76 bottom half at some point (there is also gobs of Honda Bond hanging in a couple areas).

I will get some pictures up soon as I get a photo bucket or something.

[Bankerdanny]

Welcome, with the knowledge and assistance available here there isn't anything you won't be able to rebuild.

Look at the engine number on the case on the right side next to the starter motor cover and cross reference to the information you will find over at the 550 model part of SOHC4.net. That will tell you if the engine, or at least the case is a '76.

Other than the serial #, I don't think there are any external ways to tell the '76 from a '78, but I do know that the inside of the valve cover is a bit different because they modified how the rocker arm shaft is held beginning in '77. The filter and housing are the same for all 500/550/750 engines (well, the very early 750 housing looks different, but fits the same, and I think the 350 and 400) plus the early Goldwings. So the '76 on the filter doesn't necessarily mean anything.

I haven't tried to free up the spare '74 engine I have, but I know a very popular fluid for this purpose is a 50/50 mix of kerosene and automatic transmission fluid.

As long as the cases aren't cracked, the engine is rebuildable.

After a few posts you can upload pictures directly without an external photo account, just typically not more than 2 at a time unless you shrink them down to a smaller size, say 600x800.

[Bankerdanny]

Take a few hours and read this and then like most of us weep that you will never have the patience to do what SoRon did: http://forums.sohc4.net/index.php?topic=86697.0

[SOHC4 Cafe Racer Fan]

If you don't own one already, purchase an impact driver and some JIS + bits and JIS + drivers.  They are different from Phillips head drivers, which will strip the screws.  You pretty much HAVE to used an impact driver.  Also, download the service manual for the CB550 found here on SOHC4.net, print it out and put it in a binder in your garage.  It will not only have all of the recommended tolerances and torque values, but also a list of suggested items for a 3,000 mile service.  It is highly recommended that you do these service items, aside from what will include an engine rebuild.  Good luck.  There are lots of members here ready to help.

[lightsareout]

Thanks for the link to SohRon's thread - looks super helpful!

I've been reviewing the shop manual already and building off of Dino's youtube videos of his 750.

I do need to pick up an impact driver, are you referring to just the ones you tap with a hammer?  I have a cordless impact if this would function the same way and meet the need.

I was looking to pick up a Haynes or Clymer manual; which is better for a 78?  I got confused when the Haynes says it is only up to 77.

[SOHC4 Cafe Racer Fan]

The hammer style impact driver seems to work best as the concentrated blow of the hammer keeps the bit from slipping and stripping the heads of the screws.

[Bankerdanny]

No no 1000x no on the electric impact. Trust me, using a power impact on any kind of screw, philips, straight, hex head, etc, as opposed to a bolt is a recipe for a stripped smooth screw head.

Stick to the hammer type manual impact. Just get the cheap one from Harbor Freight. I have found that the heads that come with most impacts are sufficient because the force of the hammer seats the bit firmly, but do definitely invest in a set of JIS hand screwdrivers, they will save you a lot of cursing when disassembling bar controls and carb float bowls.

[lightsareout]

Last night I continued stripping down the bike and got nearly everything off.  Next job is to pull the motor.  I can see I will need the impact sooner rather than later as I am unable to remove the crank case cover screws; they are very rusted.

[calj737]

Before you yank the motor out, remove the spark plugs and drizzle some ATF/Acetone in a 50/50 mix into the cylinders. Leave the motor in the bike. This will help you possibly free up the motor by putting the bike in gear (3rd or higher) and rocking the bike to help rotate the crank.

Else, once the motor is out, you're left with only being able to remove the head and jugs with less stability. If you can free up the motor, it might be best to let it be and cycle it to get a better assessment of its health. Then you know what rebuild or servicing needs to be done.

[lightsareout]

I put it in gear and couldn't rock it at all with a couple days soaking on it.  I picked up an impact (what a life safer!) and started pulling the side covers off, what a mess.  I had one screw I had to drill out but was able to catch with a bigger phillips bit and one I ground out with my dremel and was able to grab and rotate out with a vice grips.  Once I get the engine pulled and the head off I'll light the kerosine on fire and hope that does the trick.

Hope the stator/coil/rotor are salvageable.  Looks like sand paper and WD40 may be the route to go on these?  The more I look at the rotor in the picture it may be shot.

have some weird looking corrosion under the points plate.

[lightsareout]

Got the motor pulled today after fighting with the rear upper mounting bolt (The collar spacer was rusted firm and would not move; ended up having to grind the bolt in half to get the motor out).  The top end broke down fairly easily.  Cam and lifters look good to me but that was where the good news ended.  The cylinders look really bad to me.  Once I can get them freed what is my next step, can honing correct this much corrosion or am i looking at getting them bored out?

I found that the bolt hole for the cam chain tensioner has a small chip in it, i don't have a picture of it but will get one. Will this be a problem for me?

Do the valves looks salvageable?

[calj737]

I would think you are looking at a re-bore. At least 2nd over.

[SOHC4 Cafe Racer Fan]

You could buy a used set of cylinders on ebay, but it'd difficult to see exactly what you are getting.  If you want to stay with the original stock displacement, you might want to contact BillBenton and see if he has a good looking set that you can hone and use.

Otherwise, you could get a 2 over OR buy a cruzinimage (ebay seller) kit OR Wiseco/JE or Dynoman kit.  The cruzinimage will give you a slight bump (not as noticeable without porting and a cam) because it is stock (lower) compression.  The Wiseco, JE and Dynoman kits offer higher compression pistons that mate well with a port job and cam.

If you are going to pack miles on this bike or want to keep it on the cheap, maybe just go with a 2 over.

[lightsareout]

Made some progress this weekend, ran up to Indy and met member M_a_t_t who was selling a 74 frame/motor/parts and a separate 75 motor with carbs.  Both motors turn over, its possible that both could be running with minimal work.  The 74 frame near every part i'm missing on my 78.

So now I have some decisions to make on which parts to use, if I should save the one frame and build it after the first is completed.

[lightsareout]

I've been inventorying parts and trying to figure out my plan with all these parts.  So I think I will build 2 bikes.

First bike
-74 frame with the 74 or 75 motor both turn over, i'm going to test the compression and inspect both; better of the 2 will go into the powder coated frame.  This will then allow me to rebuild the second or source parts to build one engine if both need a rebuild.
-fairly stock - fenders, front end, seat, ect
-source parts off my 78 where possible
-I will need to source some parts - quick list headlight, bar controls, rear wheel, tires, spokes, seat cover, tank

Goal of this bike is to get it back on the road with minimal work and be able to carry a passenger (my son who is helping me work on the projects and learning about motors and mechanics).

Second bike will be the 78; fully custom cafe racer inspired style.  This bike will cost considerably more to build and be much more of a time investment and require lots and lots of planing.  The wiring on this bike is shot so it will be stripped down to just the basics and rewired.  Most of the accessory parts will be moved to the 74 so I will be building this bike very stripped down and upgrading to aluminum parts where possible/needed.
-detab the frame, seat hoop, seat pan, ect
-78 motor which is currently locked up will be bored out
-performance upgrades cam/front end with dual disks/possibly more
-rearset pegs/controls
-norman hyde m bar or clip ons (will decide based on fork used)
-currently researching and getting inspiration on direction.

My Goal is to have the 74 on the road by April/May 2017 and no time goal on the 78 but going to do it right and build it into what I want.