• Don't overlook our Welcome Package, it contains many links to important and helpful information about functions at VHT like posting pictures and sending PMs (private messages), as well as finding the parts you need.

    AD

new project: 1967 CB72

The whole advance is now done electronically, I left the points and condensers in place but they don't do anything now, so the mechanical advance on the camshaft is still there but not doing anything.
 
raydike said:
The whole advance is now done electronically, I left the points and condensers in place but they don't do anything now, so the mechanical advance on the camshaft is still there but not doing anything.
Click to expand...
I just realized the crank location negates all of that. Does it index to the rotor without any modification?
 
Yes it does. You have a circuit board with two hall sensors and an aluminium rotor that screws onto the flywheel with two small magnets that trigger the hall sensors. It is a wasted spark system.
www.elektronik-sachse.de

Digital Ignition ZDG 3.23 for Honda CB72/77

Digital ignition for Honda CB72/77 (Twin), replacement for breaker points and advancer. Ignition box dimensions Width: 70 mm Height: 20 mm Length: 85 mm Length including connections: 86 mm Advantages No distributor ...
www.elektronik-sachse.de www.elektronik-sachse.de
 
More progress... the bike runs and drives. Can't go far because I don't have a registration or insurance yet. The rev counter makes noises and tends to go all the way up so I will have to open the speedo.
I bought a speedo locally for very little money and decided to try opening that one first. Can't use it on my bike because it has a counter clockwise rotating speed gauge. I 3D printed a little jig to clamp the meter in so I could open the bezel in a controlled way.
The lettering on the face plate of the meter had gone brown with age but with a little rubbing compound (commandant green) came back nicely. The numbers on the odometer stayed brown. The bezel is quite corroded, maybe a new one can be sourced somewhere.
CB72 garage.jpgspeedo jig2.jpgspeedo jig1.jpgspeedo.jpg
 
The CB72 is more or less ready, I fitted a luggage rack bought in Thailand, modified it a bit, welded in an extra bracket to screw to the rear fender to make it a bit stronger. Also decided to put a new NOS primary chain, also from Thailand, bit expensive but well, it's a hobby right?
It runs really nicely now, mechanically very quiet. Next thing to do is have it tested so I can get a Dutch period title. The weather here is really terrible so I will wait a bit before riding it to the testing station.
A good new year to everyone.



CB72 .jpg
 
raydike said:
The CB72 is more or less ready, I fitted a luggage rack bought in Thailand, modified it a bit, welded in an extra bracket to screw to the rear fender to make it a bit stronger. Also decided to put a new NOS primary chain, also from Thailand, bit expensive but well, it's a hobby right?
It runs really nicely now, mechanically very quiet. Next thing to do is have it tested so I can get a Dutch period title. The weather here is really terrible so I will wait a bit before riding it to the testing station.
A good new year to everyone.
Click to expand...
And a good New Year to you as well.

Except for the blue plug wires, the bike looks like it might if you just rode it home from the store in the late '60s, original and stylish as the era was. It's a marvelous bike. (y)
 
When cleaning the floor I found a metal pin, did not think much of it until in the middle of the night I suddenly realized this was a crankshaft bearing locating dowel. Now the question was from which engine it came since I also have a C77 dream and a spare engine which all had been apart.
So after some deliberation I decided to take the engine out of the CB72 again to check. And yes it was from the CB72... In the picture you can see the missing one.. I'm glad I don't run a business repairing other peoples motorbikes... Took quite a few hours to put everything back together again.
IMG_20241225_111853_364.jpg
 
Nice job Raydike, I will be interested to see any reports you have on the performance of the Sachse igniton system.
From a NZ dollar point of view they are very expensive so I have been saving my pennies....
After some research they seem to have been in business long enough for the company to be reliable and trusted into the future.
The product looks great at least on paper. I think there is one other VHT member who has fitted one.

I haven't seen any contra opinions about them so far.

cheers
 
Today finally received the new license for the CB72, The test went smooth except for a mistake where they put the bikes capacity at 2470cc instead of 247cc.
First time I could ride the bike legally, have to get used to it. I find the kick start lever to be in the way of the brake pedal, maybe I will turn it a bit more forward.
Also after a few weeks of standing the clutch sticks, maybe that will go away after more riding. The petcock is leaking slightly even with a new rubber seal. Maybe it is the alcohol in the gas that dissolves the rubber.
Any tips for this?
IMG_20250418_104128_626.jpg
 
Last edited:
Drove around a bit more today. I noticed the front suspension to be very stiff, uncomfortably so. I checked the oil, 200cc in both legs, and quite thin so that can't be the problem. Maybe the left leg is stiff because of the too long fender fixing screw that dented the casing. I found a NOS one on eBay and ordered it. Hope it will arrive soon. Not cheap with shipping but way cheaper then csmnl.
 
Today I removed the fork leg and decided to cut the casing in two. Now I could remove the lower bronze slider. It was a little deformed so I dressed it with a file. Now I have to wait for the new part to arrive so I can put everything back together.
IMG_20250426_143237_757.jpg
IMG_20250426_161649_947.jpg
IMG_20250426_150506_252.jpg
 
Raydike, Really interested in the rust inhibitor Owatrol. Have you used it before in moto exhausts? Will it hold up to the exhaust temps. Can you use it alone or does it have to be mixed with paint?? I have a cl160 exhaust/muffler in good shape I want to preserve!! Sorry , do not mean to hyjack the thread.
 
Hello Yakeye, yes I also put Owatrol in the exhaust of my car. It bonds with the rust that's already there and prevents it from rusting more. The exhausts last a lot longer that way. I does not have to be mixed with paint. It might burn off in the really hot parts of the exhaust but it is the part where moisture collects and creates rust that it really works well. This is the stuff I use: https://www.owatrolusa.com/product/owatrol-oil/
 
You must log in or register to reply here.
Back
Top Bottom