[Grand Designs] project - my ETZ 250

[Blurredman]

Congratulations!

You will need a bearing puller for that one bearing in the gearbox that is only accessable from the one side however.

I'm guesing the crank bearings feel kinda crappy?

[dirtsurfer]

Congratulations!

You will need a bearing puller for that one bearing in the gearbox that is only accessible from the one side however.

I'm guesing the crank bearings feel kinda crappy?

I think I have located a puller that will do the job

Yes crappy bearings indeed. I'm thinking about having the cases vapour blasted as I'm not making much headway cleaning manually with the generator side crankcase.
I took the cylinder to the rebore man and we wait for a new piston ; 69.5 ; to arrive.

As for the rest of the bike; Well I did find a pair of skinny tyres, city demons from a bloke nearby who is restoring a Zundapp and still racess classic bikes at 78 y/o. I fitted the rear but still waiting for wheel bearings, brake parts, sprocket and cush drive.


Otherwise the frame sits sadly in the corner as my first priority is to get a functioning engine

[dirtsurfer]

I picked up the crankcases from the vapour blaster. Originally I left only the generator side because I only wanted to clean up the very coroded and pitted area and keep the patina on the outside of the case but the whole thing got done so I got the other side done to match


Checked that clutch was in spec and replaced the thrust bearing



I have replaced the rear wheel bearings an sprocket carrier bearings. Still waiting on a few more parts before engine re-assembly begins. I have now spent more on shipping for parts than I paid for the bike itself

[dirtsurfer]

Progress on my Grand Designs project has slowed up a bit, as I wait for gearbox parts .Some bearings fitted to crankcase


Headstem bearings replaced


I actually found some shielded type bearings which I replaced the front wheel bearings with


I have an impressive collection of old bearings from this bike that have been replaced


Bottom triple clamp after the vinegar treatment

[dirtsurfer]

brake caliper needs a tidy up

[dirtsurfer]

Well I had a little setback as I fitted a wrong bearing which became apparent during my attempted re-assembly of the crankcases. When I separated the cases again I moved the crankshaft on its bearing by about 2.5mm


I'm not sure if I should pop it out and refit or press it into place.


Anyway the project must be put aside for a while as I prepare this :


for this:

[Skyeport]

Next step is to prepare your ETZ for that journey
Enjoy the dirt surfing.

[Puffs]

MZ had firm roots in proper enduro, with multiple ISDE/ISDT victories!

[dirtsurfer]

Back from the desert unscathed..

Baby steps
Crankcases together:


Silly me with all the bits and pieces that I have ordered over the last few months, I forgot the worm drive that sits on the end of the crank shaft . (tacho drive)


I will see if I can find an ordinary M12 nut.

[dirtsurfer]

Next step is to prepare your ETZ for that journey
Enjoy the dirt surfing.

Interestingly Skye, I met a fellow who rode many of the outback road on an MZ250 back in the day, I'm told his trip was documented in the since departed Two Wheels magazine. If I can find the article , I will post it up

[Skyeport]

Cool. That'd be great, I'll check my collection!
the red dirt ingrained in mine when I got it (still some left) made me think mine had been outback at some point.

[dirtsurfer]

I had replaced the big gear on the gearbox input because the old one had wear on the splines. Of course the new big gear is not compatible with the worn driving wheel clutch centre causing significant resistance on rotation


and so the story goes

[parrbd]

What was the cause of the incompatibility?

[DAVID THOMPSON]

gears like this do not work well when one is worn and the other is new,
some times it does work but makes lots of noise..
dave

[dirtsurfer]

What was the cause of the incompatibility?

I could not rotate the big gear a complete turn when it was meshing with the clutch centre. It would just bind. If I refit the old one - no problems.