Topic: Project - Heirloom (1971 CB500)

[Stiggles]

Hello everyone,

I recently inherited my father's old 1971 CB500; a bike which he had always meant to fix, but never got around to it. This bike, while being his main ride for over 20 years, has been behind a hastily built false wall in his basement for the last two decades. After pulling the wall down and carrying it up the stairs (it took 4 people), I decided that it would be a good idea to bring it back to life.

It doesn't look too bad, but there is already a list of repairs needed. My father would always tell me that there was something which needed to be replaced, rebuilt or repaired in the transmission. Unfortunately he never wrote it down and I don't remember what it was. He left a small cache of parts off the bike, but there's no telling which is the bad one of the bunch, or if it's still in the transmission. Unless there's a better solution, pulling apart the transmission and checking everything against the specs will be the first item on the list.

The current list of items for this project are:
 - Figure out what is wrong with the transmission, repair it and put the transmission back together.
 - Clean off oxidation from chrome parts.
 - Repair exhaust : the tips are not actually welded to the exhaust, causing them to move very freely
 - Repair or replace seat cover: There are two small holes in the vinyl.
 - Rebuild front brake system: somehow the front master cylinder overflowed and emptied itself out during its time in storage, the front caliper has very likely seized without any brake fluid.
 - Replace or repair gas tank: It looks like it was originally green, and there's rust inside the tank from 20 year old gasoline.
 - Engine service and tune up: I have no idea if it runs, as the pictures show, there's a few pieces missing.

There will definitely be more things to fix as this project matures. This is my first motorcycle, my first carbed engine and my first time working on anything nearly twice my age. The main objective of the restoration is to bring it back onto the road in good condition. Are there any tips for a someone new to the vintage Honda scene?

[goldarrow]

did you visit the new member introduction?

the bike looks really nice to begin with.  if i were you, i would focus on getting it running.  first business is download the manual.  the 500 has common issue that it's difficult to find lower gear.  so, get it up and running before you start tearing it down.

welcome to the forum.  be sure to visit new member section.

[Scott S]

 Wow. Cool bike. I don't think I'd change it too much. The early 500's have some different and unique features.....latch instead of plunger on the seat, smaller tail light and reflectors on the fork ears, etc.
 I'm digging the air horns!!

 Just clean it up, do the 3,000 mile service, clean the carbs real well and see how she runs and rides.
 FYI: CB500 transmission parts are, for the most part, NLA. You'll be watching ebay or looking for a parts bike. Or, a CB550 transplant.

[Stiggles]

Thanks for the input! Thanks for the advice, goldarrow. the more I get into it the more prudent it seems to get the bike running before pulling the engine apart, even as just a test, to see what needs to be repaired.

Over the past week I have started to both inspect and prepare the bike for a test start of the engine. There doesn't seem to be anything wrong with the parts which were left out of the transmission, but I've sourced new friction discs for the clutch as a preventative measure. There is one very odd issue: I've been going over the service manuals, both the Clymer and the official Honda manual: the Clymer mostly seems to match up with the diagrams but the official Honda manual for this bike does not. The biggest difference is in the shifter mechanism, the '71 shifter mechanism in the manual is different from the mechanism in the bike (The shift drum stopper is totally different). I'm going to have to assume the engine was swapped, which leads to a question: were there different shifter mechanisms for different year models of the CB500?

Another question: is there any reason to not use synthetic greases, like Mobil 1, in the clutch lifter mechanism and other greased parts?

[goldarrow]

Trust me you don't want to start oil thread war!  lol :p do forum search and you'll see why

[Stiggles]

I tried to do a search, maybe I hit the wrong button since, oddly, "grease" had no hits. Question retracted.

[onepieceatatime]

I tried to do a search, maybe I hit the wrong button since, oddly, "grease" had no hits. Question retracted.

The search function in the top right is broken. The Google custom search on the top left works.

[Stev-o]

Welcome.  Will the motor turn over, either by kickstarter or electric start?

These bikes need a good battery to run, so you may need to put on on the list.

[Stiggles]

Welcome.  Will the motor turn over, either by kickstarter or electric start?

These bikes need a good battery to run, so you may need to put on on the list.

Whether or not the engine will turn over is a complete unknown: I got the bike with the clutch and shifter disassembled and the engine is totally drained. In the next week or two I should have it all reassembled and get a few test kicks in. The caked on grease/mud cement from the chain under the clutch cover and the manual mismatches have slowed me down a little.

A brand new AGM battery has been installed and is fully charged for when the time comes (the old battery was removed around 20 years ago). I may sound like a total noob here, but these bikes have an electric starter too? I thought it was only a kickstart.

[Stev-o]

Yes, it should have electric start. Look on the right hand control, there should be a small thumb operated button.