What Year Is This Suzuki M12?

[4Nines]

So this was my most recent "barn find" and I have no paper documentation on it. Does anyone know how to date this bike? I think they only made the M12 between 1963-68?

Any help would be greatly appreciated!

I forgot to take some good pictures of the bike before I tore into it, but it's the one behind the Honda

[Motorcycle Forum]

[DrBob]

I don't have suzuki frame numbers from before 1970, but if I had to guess I'd say it was a '66. The '67 and later used a tail light that mounted directly onto the fender. Your's has the wrong tail light for either style, but as the plate bracket and tail llight stick up like the early version did it looks like someone left the original bracket and bolted on a new light to replace the broken factory lens. The frame number is also too low to be a later production model.
Also, the only year I have seen without a chrome front fender was the '66. But then again, this may have been replaced also, so I am really just making an educated guess. I'll keep digging though- maybe I can find something on paper listing the older frame numbers.

[4Nines]

Thanks for the info!

The taillight was throwing me off as well. I was looking for that to be the identifying mark, but it could be replaced. The weird thing is it looks about as old as the bike so I thought it was original. Maybe it was replaced in the 60's?

I also think it's weird that the frame and engine numbers start with M10, isn't it? But the plaque on the side clearly says M12.

FYI - The odometer only shows 4,000 original miles on it so I would assume 95% of it is original.

[DrBob]

There is no telling- Suzuki was not real careful about frame and engine numbers back then, so there was a lot of weirdness. Obviously not an M10 though: wrong front end, wrong exhaust, wrong rear fender. You are missing the luggage rack, but other than that the moped looks complete. I agree the tail light looks period- the stock one was an oddly shaped plastic thing, both expensive and very hard to find on this side of the pond due to the small number of Suzuki dealerships in general and the even smaller number of this particular model sold, so if the lense was broken I can see how someone would just bolt on whatever was available.

[4Nines]

Looks like you were right! I found this little bugger in a box of parts the came with the bike. Now I just gotta find a lens

[4Nines]

Next question:

So the kickstart seems to be frozen. The kickstarter will move about 6'' before it stops dead. Nothing moves from what I can tell and it doesn't make any sound. So I figured that since it had sat for probably 20+ years that the cylinder would probably rusted to the jug. Not biggy right? Well I decided to pull the motor, free things up, maybe put a new ring in it and call it a day. Well I loosen the jug and go to pull it off thinking that the piston would come with it and it didn't. It slid right down the jug no problem. The gear on the chain spins no matter if it's in gear or not. So now I've pretty much got the motor apart and still can't figure out what it is. I guess I'm going to have to break it all the way down and separate the case? Any other ideas what it could be?

[DrBob]

Yup, that is the original tail light base. Good luck with the correct lense...probably be easier to get the more conventionally shaped base and lense from a M10- I see those lenses for sale all the time, as it fits many models, but I do not recall ever seeing one for an M12. The bike has little value even in perfect condition, so not having the right tail light is not going to hurt value, where as tracking down the right one might cost you 10-15% of what the biek is worth for just that one part.

Are you saying the output gear spins with the transmission in gear, or the output shaft?

[4Nines]

The transmission gear. I'm not sure exactly where the output shaft is?

[4Nines]

Is it the gear and nut to the right of the clutch in this photo?

[DrBob]

OK, now I am confused. In your previous post you made it sound like the gear on the output shaft from the transmission (the one the turns the drive chain) was spinning freely even when the bike was in gear. But your photo is of the other side of the engine/ trans assembly, and that is the crankshaft, which drives the clutch and thus the trans input shaft directly.

Go to this site:
Alpha Sports - Suzuki Motorcycle Parts Catalog

Click in "1968" on the listing on the left, and you will find the microfiche for the later model M12. Everything is the same as your earlier one except the tail light, so it will let you get your bearings and describe what your issue is.

[4Nines]

Yeah sorry about that. The gear that spins the chain is the one that's spinning freely. I happened to just have a photo of the clutch side and posted that hoping that it had the crankshaft in it

Thanks for the link! I'll check it out now.

[DrBob]

IS the shaft the gear is on spinning also, or just the gear? Could be as minor as a woodruff key, or as major as a trashed transmission, depending on if the output shaft spins freely or not.

[4Nines]

I just put a wrench on the crankshaft bolt that also spins the clutch. At first it wouldn't budge at all and then I put a little more torque on it and it started spinning everything!

Now everything spins easily from crankshaft bolt, but I slid the kickstart back on and tried to cycle it by hand and it's still stops in the same place as before and nothing cycles like it does when I put a ratchet on the crankshaft.

So I guess something with kickstart itself is frozen? I guess I'll have to split the case after all?