War and Pieces- Soviet Sidecar Rig Resurrection
Once upon a time there was a documentary film-maker that traveled to Lithuania to shoot a film. While there, he saw some of the local citizens motoring around on old Russian motorcycles- some with sidecars. Thinking that looked like a lot of fun, he made some inquiries, and eventually met an old gentleman who told him "Da, no problemz, for you I make the sidecar motorbike, use only new parts, you take to America, no problemz!"
So, after a long wait, a lot of haggling, lots of palm greasing, and a nightmare of a shipping adventure, he had his shiny, newly restored, 1957 IMZ M72 sidecar rig parked outside his home in the good ol' USA.
I'm not the documentary film-maker, but I also like sidecar rigs, having built my first one this past summer, with a friend of mine. I've been having a blast on it ever since.
I kept hearing about the cool old sidecar parked on a sidestreet in a quiet part of town. Nobody knew just what it was- some said it was a BMW, others said no, it was a Chinese copy of a BMW. When someone told me "Man, it looks like something Batman would ride!" I had to go look for it. This is how I found the ol' gal:
More! More! More!
Awww sad that it got left out to rust. Hope to see it on the road again soon!:clap
I took some pictures of the rig and posted a query on Russian Iron for help identifying the thing. I knew it was Russian, but that's about it. The guys over there identified it as an IMZ or KMZ (Irbit Motor Works or Kiev Motor Works) M72, a bike the Soviets first copied or made under license from BMW of the BMW R71. It's a 750 sidevalve motor, 6 volt positive ground electrics. The design was already 20 yrs. old in 1957.
It looked pretty rough and I wasn't sure what parts were missing. The tonneau cover was stretched as if a fat lady had used it as a hammock. It was evident it had been full of wet snow over a few winters. the tub was full of leaves and acorns and the seat was all mouldy. The rig was sunk into the ground up to the rims and the tires were all flat.
Anyway, after finding out what it was from the RI guys and doing some reading on my own, I was intrigued enough to call the number on the sign.
I think I've seen pictures of that rig in the hack forum...
Plus, I was inspired by RomaDakota's awesome MV750 build thread. It's what got me interested in these old Russians to begin with:
Oh crap, I bought another POS...
Finally after a couple weeks of lurking and reading about M72s I called the number on the sign from outside the filmmaker's house. this was just before Christmas. The owner was a good guy and he told me the story of how he got the rig, the details of how it was built and the old boozer who built it, the travails he had getting it back here and titled, and the mechanical issues he'd had since. Evidently the bike was hard to start, so he gave it over to a mechanic friend who got it running semireliably and brought it back. But when eventually the kickstarter stopped working altogether the mechanic had had enough. That's when the bike began it's lonely vigil in front of the house.
Anyway, the owner was looking for someone who would give the bike a good home and he told me figures he had turned down from other prospective buyers. They were all surprisingly high. I told him what I thought it would take to get the thing back on the road and what I thought I could afford to pay and still do that, all the while halfway hoping he'd say No. What was I going to do with another project? Where would I keep it- my shed is full!
Sold! he said. Crap! I thought. Too high. Anyway, we shook on it and after the holidays I went over with my neighbor and we got the rig home in my truck in two trips.
I pumped up the tires with a footpump. The mud cracked around them and it rose up a good three inches. We got it in neutral and rolling. I had soaked all the connectors with PB Blaster the night before, so we were able to separate the car from the bike easily enough.
...I gave the bike a quick spray down and let it dry, then trundled it into the basement. No room in my shed. The sidecar went into the neighbor's garage. I haven't figured out where this thing will live once it's back together. I'll worry about that later...
I'm no mechanic. I do maintenence on my bikes, but I've never rebuilt a motor before. This is my first endeavor with a total rebuild. Just jumping in feet-first. What can go wrong?
I got the bike in and situated after shifting loads of crap around. Where did I collect all this stuff?
I have bought neglected junkers before and been fortunate enough to get them running after installing new batteries, rebuilding the carbs, and general tune-ups, but it was quickly evident that wasn't going to be the case.
Under some dirt I found this manufacturer's stamp. I think it means IMZ. Anybody know for sure?
The casting is top notch, eh?
General rust and grime everywhere..
The carbs are K302 flat-slides with an off-set bowl. Pretty cool, but crude. My reading says these are incorrect for the bike- I need K37s, which are copies of the old Bings that one still might see on a /2 Beemer.
Check out the precision ground screws holding the slide in.
Eww! The intake chamber was full of goo. The bowl had actual varnish crystals. All the o-rings and little paper gaskets are toast. I found rebuild kits in Estonia!
Oh, this is good. :lurk
The outfit is a M-72M model made by IMZ and designed in 1955, first produced in 1956 so it's not a 20 year old design. Neither is it positive ground unless someone has replaced the G-414 generator and RR-302 regulator with parts off an earler model. Standard carbs were K-37A which are not Bing copies. The mufflers fitted are KMZ style, rather than the fishtails used by IMZ. The tank knee-pads are later IMZ style. It probabably had "Irbit" waterslide stickers on the tank and was almost certainly not originally black.
Breaking it down..
I started dismantling everything and bagging stuff up. The bike has some really neat design details. For instance, the two throttle cables meet at the twist grip and are captured by a little rectangular piece that rides in a slot that is machined around the inside of the grip. It keeps the whole profile of the grip slim and consistent, rather that having a bulky pod with a collar to capture the cable ends.
Another cool detail are the clutch and front brake levers. The cables for these enter the bars before the grips and travel through to the end of the bars, where they are fixed to the ends of the levers. The levers pivot at the ends of the bars, so they're inverted from levers on modern bikes.
Under the steel frisbee that covers the air filter is the air filter apparatus, which apparently is a fiber element between two screens that sits in an oil bath. I removed this and set it aside for cleaning later.
There's an airtube that passes under the filter that acts as the choke feature. There's an inner sleeve that
can be opened or closed to regulate the air flow to the carb intake tubes. Simple as it gets!
The electrical system is basically a switch, battery, coil, generator, and relay/regulator, points and condensor and distributor. Headlight, tail-light on bike, and marker light and tail-light on the car. It's wired positive ground right now. Maybe I'll try repolarizing the generator later to make it negative ground, but I don't really see the point.
The coil and distributor cover look like they're made of Bakelite.
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