few things on this I've been wanting to take care of, for years.
1st thing was the ignition. always wanted a cdi on it, but the crank end is an odd size. bought a vape for a ke125 and while the stator works, the stock crank taper is smaller than most. its a 3 year 1 model motor, so odd. working with economy cycle and vape directly, a suitable rotor was decided upon after test fitting and me 3d printing different taper adapters and relaying I info back to vape directly . the rotor that will work will be on way next week.
also, I bought all nos rear sprocket parts to replace the stock dual sprocket setup. tgis is a weird one, so I thought olid post up a few pics of the new bits. yes, the large sprocket moves out for offroad gearing.
re: dual range sprockets. Always wondered if alignment between CS and rear sprockets would cause a chain problem? Seemed like a good idea at the time but wouldn't it necessitate carrying a separate length of chain + Master links to change on the fly when you are out and about. Would kind of take the cool factor out of it for me.
it came stock with them, the extra master and section of chain. the large sprocket is dished so as you tighten the 4 bolts up, it lines up. its a bit manual & rudimentary, but very clever. I never use the big sprocket but have ridden w it. its a wheelie machine in 1st gear and won't go over like 30 mph maxed out in 4th. lol ive had it sort of off road once, its dismal in anything but a relatively smoothed paved area. :shocked: lets be honest, its a mid 60s designed camping bike.
Very cool :metal: :metal:
Now that is way before my time and a first sighting for me. Very unique motorcycle and pretty to look at. I imagine in this day of age it must draw attention from all age groups. So how fast or rather how does it scoot along using the smaller rear sprocket?
you and me both, i was negative 5 when that was built. :patriot: itll do 60 pretty easily, will hit 65 its a 4 speed and has the rotary shift pattern or n-1-2-3-4-n-1-2-3-4 and so forth.
its actually 115cc. weirdly the g series went to an iron cyl in 1970, this ones aluminum, and honestly just better. its a tiny bike but it gets attention for sure. I've owned it since 2013.
cdi test fire with 3d printed taper adapter. timing is close, but this was only to make sure everything worked. will wait till vape opens back up on jan 5th or so and ships out the 'correct' rotor for my application.
Ooo that's so cool. I didn't know Vape did one offs like that. Good work as always.
Were you able to run it with the 3d printed taper adapter or did you use that as a model to get one machined? The reason I ask is that I want to use a modern inside out rotor with side cover mounted stator on a GT750 and I would need a similar, but larger adapter.
I ran it with the 1.04 mm thick(wall) printed cone adapter on the drum that came with it
I fed back to them what i needed, and they replied back w a part number that is NOT on their website as off the shelf, but exists.
as far as getting one made, its actually a very had part to actually machine. you wouldn't think so.. but it is. a new drum that will fit is ~90-100 usd. literally not worth my time to just not replace it.
correspondence was as such:
Mark,
Our technician has a solution for you:
He marked the diameters on the rotor; the one he is proposing is 1 mm smaller in diameter. The question is whether this will be sufficient, because its insert has a wall thickness of 1 mm.
If the rotor is suitable for your needs, then the rotor No. A-A70R-94 could be purchased here.
Please check on this and let us know,
Katerina
From: Mark comporium.net>
Sent: Friday, December 12, 2025 12:52 AM
To: vape.cz>
Subject: Kawasaki rotor: more information
Katerina,
I drew this up yesterday, 3d printed it today out of abs. This, slipped into the vape rotor seems to fit quite well onto he crankshaft. Obviously not a fit but a test.
I imagine the taper is created with a reamer. My assumption is, if the reamer was not driven as far into the rotor, it would then fit.
Is this an option to have done, then I can purchase a rotor that is made to fit my application? it would be greatly appreciated.
-Mark Haase
retimed it since i just literally threw it on before. this is a much better vid.
excuse the sniffling, i have a cold.
It sounds great Mark.
My machinist is not in the very interested in machining a thin wall tapered tube unless I can guarantee that I have accurately measured the tapers to be sure it will work. It might be simpler in my case to buy a suitable VAPE combination of parts or to have the crank nose built up with weld and machined to the new larger size - assuming that is possible given the size it has to grow to.
I may have to take a stock alternator rotor and pull the bub out. That would give me an ID that matches the shaft diameter and taper, and have the OEM alternator rotor machined down to match the new rotor.
Thanks for you input
reach out to vape tell em what you need. it starts as a blank and is reamed out. the new rotor is cheap. heck they may even sell a 'blank' you could get reamed the proper depth/angle.
I finally got some cross referenced springs & plates for the clutch in, heavy duty Barnette ones, and finally FINALLY, the clutch doesn't slip. took it out for a test run tonight (still on the printed taper adapter) at night, and it was great. even pulled a little wheelie in 1st, low but off the ground almost all the way thru 1st, about 5" off the ground. the headlight was surprisingly useful, being a 6V bulb but seeing a constant 7v. very very happy w the result so far.
Little ripper! What's the rough temp down there?
today in the middle 50s. I rode to work today. yesterday about the same. did a small group ride for NYD.
finally got the new rotor for the CDI from Vape, John at Economy was a huge help
and its good, only thing i had to do was trim back the ignition winding base a few mm to clear the rotor. (its just plastic but you have to be careful)
Bike was dead cold, hadn't started in a few days (in the vid).
used a piston stop after motor was set to 1.7mm btdc, then put a bungee on the kick starter to hold it in position. was pretty easy
NOTE: the rotor that worked was a A70R-94 THE '92' is the ke100 one that i had to use the taper on. that '94' rotor needs to be asked for as i dont think its on the website directory
great work :thumbs: Looks like there's a little groove in case ahead of the CS sprocket- is that manufactured that way or chain wear from a previous owner?
Very cool.
I wish I had half of your mechanical skills and know how.
Quote from: RDnuTZ on January 13, 2026, 09:32:26 AMgreat work :thumbs: Looks like there's a little groove in case ahead of the CS sprocket- is that manufactured that way or chain wear from a previous owner?
its made that way. the next year or 2 had a hi lo range, and that casting was open and integral to that. however in early 67, they hadn't implemented it yet, so thats why it has the weird dual rear sprocket. its a really odd bike. and thanks, I was determined to update the electrics for years
then there was this.. :undecided: :dawg: had the go pro running so .. the stud pulled and headgasket went kaplowie. luckily no real damage.
bummer. Stud just back out a couple turns or actually strip portion of itself and/or threads in cylinder?
threads in cyl gave up. repaired that last night, installing now. I mean, thats all part of it. :devil:
heres the video.
Doh! Glad it was an easy fix with no other damage than the threads & gasket.