MZ/MuZ Riders

Hi all. I have a 1987 ETZ125 with the separate oil tank and pump arrangement. Can anyone explain the potential damage that might occur to the etz engine when riding at a constant speed (ie full throttle) for extended periods such as dual carriageway where the pump would not be operated as the twist grip remains static?

Hi, I must admit I wondered how it all worked when I was wondering about converting my ETZ standard to an oil pump. Although the literature all describes the pump as being "driven" by the throttle cable, I'm pretty sure that the cable is used to control the metering, but the oil pump has a fitting onto the end of the crankshaft, and the actual "pumping" is done by the rotation of the engine. So in answer to you question, it should be fine!

Don't know about your model, but on the ETZ250 the oil pump runs from a slot on the end of the input shaft to the gearbox. So if you're in neutral and idling it's possible that you might get no lubrication if the input shaft isn't rotating or rotating slowly.

Apart from that, I agree that keeping the throttle opening at a constant speed won't do any harm to 2 stroke oil feed.

On the ETZ 250/300 models the oil pump stops working if you pull in the clutch, unlike most other two strokes, so its not advised to sit at road junctions or traffic lights in gear with the clutch in.

The pump is running with the engine in neutral.

Thanks for the heads up there Skorpion. I was being extra careful about sitting still

And in my town, there are enough traffic lights per square yard to make this an important factor

the Yamaha ym1 305 i had in 1966
the pump run from the motor and the wire from the throttle changes the stroke of the pump
seemed to work good 132,000 miles in 6 years and still had original rings and pistons ....and bearings
dave

DAVID THOMPSON wrote:the Yamaha ym1 305 i had in 1966
the pump run from the motor and the wire from the throttle changes the stroke of the pump
seemed to work good 132,000 miles in 6 years and still had original rings and pistons ....and bearings
dave

That's amazing David.
I have a 1993 Yamaha RD350R YPVS and I'm told by those in the know, that it will be lucky to reach 25,000 miles without a full top end rebuild.
But I know of MZ 250s that have over 100,000 miles and are untouched.

i think it has to do with the rider and how hard they run it
i was always poor and could not afford to have things break
that's one reason i used BMW for 35 years they were not cheap..
but cheap to run because if you did not flog the crap out of them
they did not break very often

other than the funny funky electrical system my rt125 has been great

my wife had a Yamaha rd250 and it either died on clutch release or wheeled with her
she never did get used to it and wound up with a 250 exciter from the early 1980's
and ran my r50s till she started having back problems she does not ride now
as after a back operation her falling off is not a option...
dave