Motorcycle Frame Refurbishing

Now that the engine was rebuilt, I started working on the frame.  I took off the few remaining parts, forks, tree, stem, and swing arm.  This view shows the frame looking at the bottom.  There was tons of dirt and grease all over 

To save time in cleaning off all the oil, dirt, and grease, I took the frame over to my buddy’s shop and borrowed his pressure washer.  I coated the thing with a whole can of degreaser, and then sprayed the thing down really good.  Even with that there were some really stubborn bits that required scraping with a scotch brite pad then repeating the pressure washing. Overall, this was a pretty easy way to clean up the frame.  

I brought the frame back to my workshop, cleaned up some of the smaller chassis parts, then set up all the parts for painting. 

I used the KBS Coatings rust seal product as the base coat.  This stuff is supposed to encapsulate any remaining rust and do a real good job of sealing off the metal to keep out corrosion.  It can be sprayed on or brushed on.  A little goes a long way and it flows out so no brush strokes are visible.  

The results with just the rust seal coat look really good.  The only problem is that the rust seal paint is not resistant to ultra violet light, so it will start to fade if exposed to prolonged sunlight.  If you don’t want it to fade, it needs to be top coated.  

I let the rust seal coat dry for about 6 hours so it was dry to touch but just slightly tacky.  Then I sprayed DupliColor gloss black enamel doing 2 light coats and finishing with a medium/heavier coat. 

Here is how the finished parts turned out. 

Ideally, I could have got all these parts fully sand blasted and powder coated, but using the kbs coatings rust seal method with enamel top coat is a pretty durable alternative to powder coating and it cost significantly less money being able to do it yourself.

The CB360 Engine Rebuild

Over the winter I rebuilt the engine for the motorcycle.  I really enjoyed this part of the project because engines fascinate me.  It amazes me that they don’t wear out faster than they do.  Think about regular cruising speed an engine is probably around 3,000 RPMs that means that each piston is moving up and down inside the cylinder 50 times every second!  

I wanted to rebuild the engine for several reasons.  The first is that I had never done it before, and was up for the challenge.  The second reason was so that I could be confident the engine will be in great shape and last many years.  It makes it easier to clean everything up if it is taken apart too.  I could probably have just pressure washed it and it would look fine.  But, the second reason why I wanted to rebuild the engine is because I had never done it before.  It looked fun, and I was up for the challenge.

The first thing I did was took the valve cover off and the clutch cover to drain the remaining oil.  

With the valve cover and rocker arms off, the camshaft can be removed.  In this engine, the camshaft does not have any bearings; it just rides on the aluminum with oil being pumped between the camshaft and the aluminum surface.

Next, I removed the cylinder head.  You can see that there was a lot of carbon build-up.  I removed the valves and valve springs measured and checked them according to the manual.  One of the exhaust valves was pretty worn so I replaced both exhaust valves.  

From here I went to remove the cylinders.  These were stuck on really tight, I tried to free it by hitting a block of wood against the cylinders with a hammer – I accidently broke a fin doing this L. 

 Eventually it came free after hitting with a rubber mallet.

I used my calipers to check the valves, valve springs, and rocker arms pins, but in order to get accurate measurements on the cylinders,  I would need a bore gauge.  I took the cylinders and pistons to C&S Performance in Butler to have the bores and piston diameters measured.  When everything checked out in spec, I had them also hone the cylinders and soda blast the head and pistons to get rid of all the carbon.  They did a great job on everything and had pretty reasonable prices.  They are not really set up to do motorcycle engines (main focus is Chevy race engines), but they were friendly and willing to help me out anyway.  For the cylinders and head, I was given a great deal on powder coat by Classic Coatings Inc.  They did an amazing job and I could not be happier with how the parts turned out.

The next step in dis-assembly was to remove the clutch discs, oil pump, and filter rotor so that the cases can be split.  In order to get the oil rotor off, a special socket is needed.  It can be found online for pretty cheap but it I did not want to wait a week for a tool to arrive, So I found an old spark plug socket and used my angle grinder to make a crude oil rotor socket.  I used this with my impact driver and the filter rotor nut came right off.  

The engine/trans case was pretty disgusting and had lots of burnt oil baked on. 

Once I got the case split I took pictures so I would know how to put this puzzle back together. 

  I removed all the parts and laid them out trying to keep them organized.

 I spent lots of time cleaning up the case, taped them off, then gave the parts a fresh paint job using hi-temp aluminum colored paint.

Over the weeks of this engine rebuild, I also cleaned and polished up the aluminum valve cover, generator cover, and clutch cover.  I started with a soft wire wheel on my bench grinder for the really rough parts, otherwise I started with 400 grit wet sanding.  After wet sanding for as long as I could stand, I used a sisal wheel with emery compound and buffed the parts for a long time.  I also used a tiny felt wheel on my Dremel tool to get into the tight places.  Then I used rouge compound with a denim sewn buffing wheel to get them even smoother.  Then finally for the clutch cover and generator cover, I put a small wheel on my angle grinder and polished with white rouge to finish the parts off.  I could have done a better job, but I am happy with the results. 

Now with all the parts ready to go, the real fun part could happen, putting the engine together!  I got a complete gasket set and all new oil seals. 

I did not have a piston ring compressor so I used a makeshift one out of some thin sheet aluminum and large hose clamps.

And here is the completed engine.  For the final visual touch, I replaced all the Philips head screws with stainless steel Allen head screws.  I am very pleased with how it turned out.  

Getting Started - The Tear Down

So the first step of a ground up restoration is to take all the parts off of the bike so that they can be cleaned or repaired.

Tank, Seat, Exhaust removed

When parts start coming off, you really notice how rusty and dirty everything is.

I took lots of pictures as I took things apart (so I could have a reference when it comes time to put this all back together), and I was also able to find a manual for the bike here.  This makes working on the bike a lot easier.  There are tear down and assembly steps for almost everything, as well as torques specs, part service limits, and exploded assembly views.

I tried my best to keep things relatively organized when I was taking things apart.

I was able to get the bike taken down pretty quick, and I felt like I was making progress.  At this point I left a few parts still on the frame.  

My main focus now was to get into the engine and make sure it was good.  I wanted to do this first before I put too much effort anywhere else because if the engine is no good, the rest of this bike is pretty dirty, that it would not really be worth restoring.  My next posts will start going through the engine rebuild.

  

Where it began

I wanted to create this site so that I can share my Honda CB360 restoration project with detailed steps documenting my progress.

Before I get into it, let me give a little history to how I got here.  If I try to explain where this originated from, or how I ended up with this motorcycle in my garage, it all stems back to when I was 18 years old.  As a kid, I always though motorcycles were cool, but it wasn't until my freshman year of college at University of Wisconsin Milwaukee, when I really started thinking about buying one.  Every day for class, I walked from the Union to the Engineering building.  This route took me past the dedicated motorcycle parking lot on campus.  After seeing all the bikes parked there every day, I thought to myself, "That looks like a really fun way to get around!"  I spent a lot of time daydreaming about owning a motorcycle and what my ideal bike would be.  To drive my interest even futher, that summer, one of my best friends bought an early 80's Kawasaki KZ440 LTD.  It had some 80's nastyness in the styling, but overall I thought that thing was really cool.  That next spring, I got my motorcycle license and was determined to save up enough money to buy a bike by the end of the summer.  I worked 2 crappy jobs that summer and saved up enough money to be able to afford an old 1983 Kawasaki KZ750 LTD.  I found the bike on ebay, and was super exited to win the auction.  I was also very excited that I got almost the exact same bike as my best friend, and had almost twice the engine!  Getting this bike is where I started to realize that I not only enjoyed riding motorcycles, but enjoyed working on them too.  When I got the bike, it was leaking fuel, it had a nasty dent in the tank, and had obviously been dumped as the handlebars were bend and turn signals were scratched.  I fixed the fuel leaking by rebuilding the carbs, I patched the dent, put on lower style handlebars, and repainted the bike my favorite color: flat black.  This is the bike I am still riding today.
Fast forward a few years to August of 2013, I am out of college, and my wife and I just bought a house with a nice 2.5 car garage that has additional 12' by 12' workshop off the back.  With this garage, I was itching for a project, and what better that a motorcycle.  I saw the 1974 Honda CB360 on craigslist with the description, "It does not run".  I looked at the add and loved the vintage styling of the bike.  Originally, I thought I would just get it running then sell it to some hipster and make an easy $500.  After I got the bike in my garage, the more I looked at it, the more I grew to love that vintage style.  Then I decided that I wanted to make this thing really nice.  I wanted to tear it down completely and do a complete restoration with some slight modifications.  I had a feeling that I wasn't going to want to sell it anymore.  Since I was gonna do such a large project, I though I would document the process and share it here for anyone who is interested.

Here is the bike just after I picked it up on Craigslist.  1974 Honda CB360G.

The bike seemed to be in good condition for being 40 years old.  It only has just over 10,000 miles on the odometer.  There is lots of rust and crud, the seat was torn, and of course it didn't run, but at least the engine wasn't seized.  According to the license plate, the last time it was on the road was in 1986.  And funny enough, there was a UWM parking sticker on the mirror from 1986 as well.