I thought this manual may come in handy for others who are restoring and riding Honda C100’s.
The auction ended without any bids, so I made a fixed price offer of $2000 and someone accepted. It’s being picked up and shipped to Auckland sometime soon (once I have been paid). I took a fairly hefty loss on this one, but it wasn’t getting used and we needed space in the garage for Toms new bike.
I forgot to update my website with the fix for the missing issue with the C100. Turns out that it wasn’t anything to do with the ignition system at all. When I put the stock Honda carb on it from the other ratty C100 a month or so ago all the issues went away. Just goes to show that even after years of fixing bikes there’s always stuff to be wrong about. I’m chuffed that it’s finally right now, although I kind of wish I hadn’t thrown so much money at the ignition system when there wasn’t actually anything wrong with it though.
Anyway, after it having been fixed for a month or so and hardly ever getting used, I have decided to sell it. Ange rode it today and unsurprisingly didn’t like it (she dislikes everything except her old ERN6N and apparently it will always be my fault that she sold it). So time to list it on Trademe and make some more space in the garage.
I couldn’t resist making a bid on another C100, this time a 1968 model. I didn’t get a chance to view it and I wish I did. It’s in a bit of a ppor state. Fortunately I have a lot of OKish parts that I changed on my other 1965 C100. So far I’ve fitted another rear wheel and tire, indicator lenses, ignition coil (it was missing) and cleaned up the carb. If I can get the carb to stop leaking I will swap it with the carb on my 1965 model. I think I’ll just get this one running and sell it. I can’t be bothered to do it up and get it registered.
I’m running out of ideas about what else to do with this.
I have a issue with the bike that has got be really stumped. It starts and runs beautifully but at high RPM, high load (95Kg of me and a hill) it misfires like it has an ignition fault, on/off/on and eventually stops. It gets worse the hotter the engine gets. After a few minutes it will reluctantly starts and goes on a bit longer until it does it again. It does it after just maybe 30 seconds of starting it and going up the hill from my house. Very repeatable.
I thought it was probably points and condenser, so I replaced them. No difference. I thought it may be some dirt in the brand new carb I fitted, so I cleaned that. No difference. I then got fed up with points and condenser (always disliked them) and splashed out $250 on a CDI conversion, magneto and everything. No difference. I then thought it might be the coil, so I fitted a new one. No difference. I thought the ignition switch might be faulty, so I bypassed it, no difference. I have stripped the engine completely (as part of the restoration to paint it) and the valves have been lapped, checked with engineers blue and clearances set correctly. I’m now wondering about the “selenium rectifier” and whether that would give me those symptoms? The bike has a brand new battery and the fuse did blow at one point, not sure why though?
I don’t think it’s a fuel related issue, I get good flow from the tank and it feels too sudden for fuel, like the spark is breaking down under the high pressure combustion of high load, high RPM.
I’m hoping to buy another wreck of a bike so I can swap some parts over for a better diagnosis.
Any words of wisdom would be much appreciated.
So, my Honda C100 has an ongoing issue with a misfire and eventual breakdown when it warms up. I’ve replaced the entire magneto assembly with a CDI conversion to eliminate the points and condensor, but the problem still existed. I then decided that I would replace the ignition coil, HT lead and spark plug cap.
Yesterday, after fitting the new coil, HT lead, and spark plug cap I took it for a test ride and the problem still exists 🙁
Now I’m wondering if the ignition switch is faulty or the loom has an issue.
The next step is to “hotwire” the ignition switch and see if the problem is still there.
If that makes no difference I think it will be having a complete new wiring loom.
After much messing about changing points and condenser, I got fed up with the ancient set up and decided to bite the bullet and buy the expensive solid state ignition system from eBay. It’s a good improvement, starts easy now. I’m going to change the coil as well, just to be certain everything is perfect. Fortunately the coil is relatively inexpensive.
The Cub exhaust has something loose inside it, so I made a video and sent it to the guy in Thailand I bought it off.
He is sending me a new one at no charge! Result!