Hi there!
I've been a fan of Honda's CB Fours for a few years now but it took me about two years to pull the trigger on a deal to aquire a nice CB500 Four from 1974 (MY1973). Somehow I like the CB500 more than its big brother.
I’m a mechanical engineer by trade and have been working on and with different kinds of machinery from my childhood. I’ve owned/repaired/restored about 30 motorcycles (mainly vintage/classical) and been riding them from when I was 12 years old. Tinkering on tractors/cars/motorcycles and other machinery has always been a part of my life. But since last year’s September, I haven’t owned any classical Japanese bikes.
I purchased this beauty from Finland in September 2018. I believe it to be an European K1, but as I know these European export models were assembled with parts from various production years. So in US standards it’s not a pure K1, more like mix of K0/K1/K2. Some parts have certainly been replaced as the bike has seen some smaller crashes and a repaint.
More on the bike. It’s first registered in April 1974 but model year is still probably 1973. According to the papers the bike has done over 104 000 kms. I’d figure that the engine has seen an overhaul sometime during these kms? When I went to see the bike it was running on three cylinders, front brake was sticking which made the clutch slip a bit and the tires were almost 20 years old. When the engine warmed up, some small oil leaks came apparent. The PO said that the bike had been basically been sitting for over 13 years. I still liked the looks and the feel of this CB500 and ended up buying it.
Sticking front brake ended up being a blocked pressure relief hole in master cylinder. Ended up flushing and cleaning the whole system. All the seals and pistons looked really good on both master and slave.
I pulled the carbs and cleaned them. Carburetor for cylinder #3 had a clogged idle jet and all of the float bowls were full of petrol residue (resin-like substance). Rubber boots which connect the carbs to the intake manifold were hard as a plastic.
Replaced spark plugs and caps, cleaned air filter. I also bought NGK J1 cable splitters as the ignition wires were falling apart between my hands. Tires are now Heidenau’s K36 (rear) and K44 (front).
After doing a small tune-up (adjusting timing, valve clearance etc) I got it to run on all of the four cylinders. I drove it around for few hundred kilometers to get a feel for it and I started to experience more and more oil leaks and a ’lean hang’. Revs were not coming down to idle and synchronizing carbs became almost impossible. Also I didn’t like how the engine sounded (chains’ rattle) and clutch was not engaging smoothly. I took a decision to pull the engine before spring to check its overall condition and replace what’s needed (at least bearings, gaskets etc). Maybe do an overhaul to the carbs as well. Right now I’m about to move the bike into my man-cave to pull the motor. I would definitely appreciate your help on checking the common faults on the engine and finding parts.
Mods, which of the sub-forums is best for this kind of small ’project’?
BR,
splitter
