Engine bolted on engine stand

When I ordered a complete gasket set for the Honda CB500K1 it came with new std piston rings. And as I wanted to clean and paint its frame anyway I decided to remove the engine from the bike and bolt it on an engine stand. After two weeks of spraying the mounting/hanger bolts with WD40 all the bolts came loose pretty easy.I started with removing the bolts from the top hangers and worked my way down. 

Tip: If you wanna open the engine for a rebuild it's easier to loosen all the bolts and screws when it's still in its frame.
I removed the brake pedal connections, kickstarter, carbies (see previous post), all electrical leads, the top breather cover,  front sprocket and chain.

Honda CB500 four brake pedal

Honda CB500 four kick starter

Honda CB500 four engine

Honda CB500 four breather cover

Honda CB500 four 17T sprocket

Even after the last long bottom bolt was removed the engine stayed motionless in its frame. The engine weighs around 75 kg but it wasn't too hard to take it out of the frame and put it on a soft blanket next to the bike. 

 

Honda CB500 four removing engine

Honda CB500 four removing engine

 In order to bolt a bike engine on a standard rotating engine frame you need four 90 degree brackets, some threaded rods and a couple of washers and bolts. I used 50x50x50x5 mm brackets but other sizes may do the job as well.
It's way easier to fix the engine stand mounting head on the engine when the engine is still laying on the bench/floor. Only downside is it's gonna add another couple of kilos you have to lift while sliding the whole lump into the engine stand. I managed to do it myself but it's f*cking heavy...

 

Honda CB500K1 engine on engine stand

Honda CB500 four engine on engine stand

Honda CB500K1 engine

Honda CB500 four engine on engine stand

 

 

Honda CB500 four engine stand

Rebuilding the master brake cylinder

 The bike came with some temporary small chinese master brake cylinder. It did work but the braking power was minimal. I guess putting my foot on the asphalt would have the same braking power...

 

Honda CB500K1 temporary master cylinder

Luckily the old clogged up master brake cylinder came as a spare part with the bike. It was completely stuck and was in desperate need of a rebuild.

Honda CB500K1 master cylinder

 

Honda CB500K1 master cylinder exploded view

 

So I bought a rebuild kit for around 25 dollar from 4into1.com and started the rebuild.

It looks easy but it can be a real pain to get all the old rusted, clogged parts out of the mater brake cylinder.

The biggest challenge was to get the retaining clip out. It sits quite deep in the narrow shaft and most tools are too fat to reach it. The best option is to use a pick or similar. For more than an hour it wouldn't move even a nano inch but then all of a sudden it snapped into 3 pieces and I finally could take it out. All the other pieces are now easy to remove.

Honda CB500K1 master cylinder old bits

I gave the master brake cylinder a good clean and sanded the inside with 240 and then 400, 600 grid and finally some steel wool to get rid of most of the corrosion.

The rebuild kit comes with some red grease which should be applied to the new rubber bits. Of course the new retaining spring gave some trouble... I pushed it in all the way with a long socket that just fits inside the narrow master brake cylinder entrance. There's a small groove in which the clip should click in.. It looked like it clicked in the groove but apparently  it wasn't and everything got stuck inside, grrr...

Honda CB500K1 master cylinder rebuild kit

Honda CB500K1 master cylinder rebuild

 

After some trial and error ther clip came out and in the second attempt I managed to get it click into its groove.

I also ordered a new cap as the old one was faded and damaged on the outside, and of course a new diaphragm. The plastic ring that goes between the cap and the diaphragm was still in perfect condition so I reused it.

Another little thing I had to replace was number 11 (part 45526-341-000) in the exploded view. It's a rubber/plastic tube and a piece of fishtank hose was a perfect fit ;)

Honda CB500K1 master cylinder bush 45526-341-000

Honda CB500K1 master cylinder rebuild

All done :)

Honda CB500 K1 1972

Back in the nineties I used to own a couple of SOHC Honda bikes from the seventies. All sold but still in my mind I started looking for a nice CB project to help me through the dark winter evenings. Browsing internet for a Honda CB I came across a 1972 Honda CB500 K1.

Honda CB500 Four advertisement

Honda CB500K1 1972

Honda CB500 K1 1972

Honda CB500 Four

The bike had been sitting in a shed for well over ten years and the engine was stuck from doing nothing for all those years. It came with a 4in1 exhaust and a poor quality custom brushed on paintjob but besides that it was almost a 100% stock original bike.

I've always liked the early CB500 bikes and as I was looking for a winter project I decided to pick up the bike as it was only a 1200 km drive (one way). It was a fun roadtrip with my bestie Batty over long flat roads across the middle of nowhere. No signs of life except for kangaroos, emus and speeding roadtrains.

The bike was as advertised and came with some original spare parts. Another nice surprise was the original owners manual still sitting in the seat and the stock airbox filter and toolkit tray were still there.

Honda CB500K1 owners manual

Honda CB500K1 owners manual

Pick up Honda CB500K1 with my Mitsubishi van

Back home I started cleaning the bike, there was a thick layer of greasy dust all over the bike.

Honda CB500 waiting for some TLC

Honda CB500K1

After changing the oil, oilfilter and adjusting the tappets and ignition timing I tried to start the bike. It made some pops but would only run for a sec after spraying starter fluid in the original airfilter box. When I inspected the leaky fueltap I found out it was almost completely blocked with dirt and tiny rust particles.

So I quickly made an external fueltank from a big syringe :)

 

Syringe fuel tank :)

Auxillary seringe tank

After some more kickstarting (the way too small battery in the bike was almost flat) the old Honda CB500 came back to life.  

                                                                   Honda CB500 K1 running

 

It probably needs a good carb clean and synchronising and some new sparkplugs but I was really stoked with the fairly easy but big progress.

Honda CB500K1 1972

 

Now I know everything is working it's time for some resto :)