C72 from France

[sky.fred]

Sniff... the delivery of my bike is delayed, I won't have it for another ten days.
I've received new Heidenau K36 tires 3.25 x 16 (Germany).



The ones on the bike aren't worn, but they didn't like getting old and are cracked.

[GrahamH]

I had trouble finding the sprockets here in UK and eventually bought a 15T gearbox sprocket for a CB77 and machined it (thinner) to fit. The chain size for a CA77 is 525 and for a CB77 is 530 i.e. it is wider. Also be sure to check the gearbox sprocket splines match the shaft as I found there are both shallow and deep spline options. Also do not be tempted to fit an ‘O’ring chain, it will not fit around the gearbox sprocket. I don’t know where to find the parts my sprocket was the last one in stock.

[Tim Allman]

Also do not be tempted to fit an ‘O’ring chain, it will not fit around the gearbox sprocket. I don’t know where to find the parts my sprocket was the last one in stock.

Thanks for this. I was thinking of getting one for my Honda because my Suzuki 650 VStrom has an O-ring chain and I really like it. It now has about 25000 km on it and with normal lubrication every 1000 km the chain has required only one adjustment to take up slack.

[sky.fred]

This will depend on the condition of my bike's parts, which I'm supposed to receive next Thursday, but I've made contact with companies in France that make custom sprockets.
I haven't been able to finalize because I need precise measurements to get a price.
If I have any made, they'll be 520, which are more common than 525.
The delay in delivery allowed me to continue my theoretical mechanical knowledge of the C72 and to start receiving some parts for the restart (spark plugs, gaskets, cable etc.).

[sky.fred]

The bike is at home





and I've started dismantling it.





The paintwork is a bit dull and some of the chromes a bit pitted, but considering the age it could be a lot worse.
The seat foam is baked and needs changing.
The air filter also needs replacing. I'm hesitating whether to put back an original one or make a custom one that can be cleaned.
I've taken the compressions and they're very good: 10.5 bars on each cylinder.
To be continued tomorrow ......

[sky.fred]

I'm not planning to renovate the bike, but simply to get it back on the road, keeping its original patina but making it more reliable. The aim is to ride it, not to display it in a museum. I'll see if I can do a complete repaint later, but I like bikes in their "juice".

For the engine, which is running, I'm going to do a major overhaul:
- Change the oil
- Check the oil pump and clean its strainer
- Clean the centrifugal cleaner
- Disassemble, clean and replace carburetor seals
- Replace tube fuel
- Adjust ignition, change spark plugs and install electronic ignition assistance - keeping contact points assy -
- Fit new ignition cables
- Adjust valve clearances
- Replace air filter
- replace the battery and check the charging circuit, but I've already seen that the silicium rectifier has already been replaced by a modern one.

For the cycle :
- Check bearings, seals and cables
- Inspect brakes
- Touch up paintwork and clean chromes
- Check shock absorbers, change oil and seals if possible
- Change tires and tubes
- Check chain and replace if necessary
- Replacing mufflers
- Replace front turn signals on handlebars
- Replace the seat foams and I'll see if it's possible to keep the original upholstery.

Are there any other particular points to check on this bike?

[sky.fred]

Latest news from the front.
The bike has already been restored.... more or less well!
There was rust in the front and rear fenders. The holes were filled fairly well with solder, but a huge layer of putty was put on top, which has peeled off in patches.
Fortunately, the shock absorber mounts and structure were unaffected by rust.
I'm going to clean it up.





The sprocket is at the end of its life and the chain is dead but the damper wheels are in good condition.





The drum aren't worn, which seems to confirm that the bike doesn't have many miles on it.