jawa nd MZ in the UK?

[gilburton]

re the mz/robin on flickr.

( viewtopic.php?f=36&t=1292#p8475 )
( viewtopic.php?f=36&t=1292#p8476 )

I have recently resurrected the project as it has had to be put aside for various reasons,the main one being lack of room in my workshop due to other projects/useful spares(or junk as my wife calls it) No imagination these women
I considered going the Enfield route but cost was a consideration and as I had the major parts to hand I decided to start again,
I have mounted the engine and added a down tube to support the engine but I found clearance a problem. I intend to fit a 16" rim on the front.This avoids cutting the frame so should pass the UK M.O.T. test.
The Robin engine is a bit of a lump and has to be offset to the right to line up.
The Aixam transmission is still an unknown quantity but because of the tight fit I may have to reverse the direction of the sliding tips to allow me to move it backwards a little.
I believe it is actually a comex? unit made in Canada for snowmobiles?
In the pic the rear pulley is the wrong way round but I may have to put it back the same as the pic. This will allow a couple of inches rearward movement to adjust the belt tension.The belt isn't actually in tension but I have found out that the pulley centres are app. 250mm apart. It works in the same way as the Comet units but the belt is much larger so wear on a bike should be better.
I have been collecting some MZ bits so once the engine/transmission is lined up to my satisfaction I hope the cycle parts will rapidly come together . Having done a few bike rebuilds in the past you probably know that it is always the smaller parts that take time eg brackets,exhaust etc.
Initially it will be an economy build as a "proof of concept" but once the problems are ironed out I'll strip it down again and rebuild with a bit more quality.
Hopefully it might be up and running this year.
Just to add I have mounted the rear pulley shaft on 2 pillow block bearings individually and have used turnbuckles(see pic) to adjust the shaft/pulley to get alignment. The shaft is mounted direct to the rear MZ engine mounts which pivot on the swinging arm and use rubber bushes as standard so these should allow a bit of movement! Once I have got it all lined up and running I'll fix the mountings so that they are more rigid in relation to each other but still have the rubber cushion(if that makes sense?)The forks are now on and I'm working on the rear end re mudguard etc.
I'll take some pics shortly and if admin wants to move this topic please do so.

[gilburton]

I now have the engine transmission in and today I had it running without drive to the rear wheel. I still have a few alignment problems with the belt but I can report that the pulleys seemed to function as intended which was my main worry as I don't really know which make of car they came from so I was a bit unsure about the sliding weights/rpm etc. I originally figured that as most industrial diesel engines run at similar rpm then it would work albeit with less power than the original twin in the car.
The pulleys are a bit bulky but they are easier to get hold of in the UK than the Comet units.
The weight seems to make the bike sit a bit low so I might try preloading the forks with spacers. The other option is to raise the engine a bit by fitting a "banana" style tank from the MZ ETZ251 which gives more clearance than the flatter ETZ250 tank.
That's it for the moment,tune in next week for the next exciting instalment of "man in shed with big hammer"

[gilburton]

thanks admin I just noticed you had moved the thread and now it's all together