MZ/MuZ Riders

Hi
I am looking at a used ETZ that has had, in the past some engine overhaul but has stood a while.
Interested in what checks one should carry out.

I also understand that the bike (I think its a 300 and not a 250, nor a wilf green special - UK) has had the autolube/oil pump removed at some point.

Can anyone comment on using an ETZ on premix and any positives or negatives to using one in that way?

Regards

M

Once you get used the pump it is very convenient, but I don't think they fitted them because the engine inherently required them. They will run fine on premix, usual caveat on over-run.

I think you will find that nearly all MZs sold in East Germany were premix, and only export models known as Luxus had the pump fitted as standard.

ETZ mix ratio 50/1.

usual caveat on over-run.

What do you mean by this
for us non British English speakers

DAVE

Engine over run is when the throttle is closed and being used as a brake. Under these conditions no fuel (and hence no oil with pre-mix) is being delivered to the engine.

David.

Surely that will be the case with an oil pump too as it is cable operated from the twistgrip?

The pump is run off the primary transmission, the dosage is regulated by the throttle, well actually by the extra cable on the throttle. Hence there is always oil being fed to the crank. You can see this if you bleed the pump. Premix in the tank, of course, and watch the oil creep along the pipe towards the inlet spigot even at idle speeds.

Of course even on premix there is some oil getting through because there is fuel getting through, but the received wisdom (and I must confess to wondering myself) is that you can starve the crank on premix on an extended decline on overrun

Ahh - that makes sense.
Personally I have my doubts about oil starvation on no throttle. Coming down off the Honister pass last year I had no throttle on for ages ( and no brakes which is another tale!) . I reckon it took about 20 minutes to get down or so and my little Trophy had no complaints at all. I don't know really - just my opinion...

Engines still use petrol on tickover, so I'm sure the oil in the pre-mix gets through.....

I've had 2-stroke mx bike for years, all pre-mix and all have been down long steep green lanes while engine braking (much higher revs than you would get on the road doing this), and no problems.

Well said, mind you filling up is much more of a chore with the premix ETS than with the pumped ETZ assuming I have filled it before leaving home.

I never had any problems at all with my ETZ125 which was a premix (and the TS125 I started learning on). Did get a seized engine on an a new ETZ251 once. Not sure what caused that as I never let it run short of 2T oil. Mind you it was stuck outdoors in the freezing cold weather all the time so maybe it was the cylinder contracting together with it being a new engine just running in. If the engine has been run in properly to start with then there should be no further problems.

David.

Old Dog wrote:Well said, mind you filling up is much more of a chore with the premix ETS than with the pumped ETZ assuming I have filled it before leaving home.

I quite like the ritual of filling up with premix. I also quite like the looks I get as I pour green liquid into my petrol tank from people who aren't in the know!

[quote="stogadog"]I quite like the ritual of filling up with premix. I also quite like the looks I get as I pour green liquid into my petrol tank from people who aren't in the know![/quote]

My local servo is run by a bike nut - lovely Bultaco outside - his Mrs was chuckling at me the last time I filled up as I counted out the number of cap fulls and poured them in.

I keep my 2 stroke oil in an old Bushmills leather bottle case that I have strapped to the rack. I have had folk ask if I was putting whisky in the tank once! You would think they would spot the whisky was green but they never did!

I'm quite tempted by pre-mixing my ETZ, not sure yet though.

Either pre-mix, or a small tank of oil rigged up to the pump..... something like a front brake reservior.... would probably only be good for a couple of tanks, but maybe better than carying oil around ?