MZ/MuZ Riders

I now have the ETZ 250 that I bought a few months ago running but.......

Although an EZT 250 it has a later carb from an ETZ 251 fitted, but I am assured it should run OK with it.

Problems / questions are:

1. It starts with no choke - new plunger fitted, slack in cable so in theory should work OK or do they all start with no choke?

2. I have the air screw set to 2.5 turns out, and bypass screw 4 turns out as per the Haynes book of lies - can anyone confirm that these are the "base" settings?

3. If I blip the throttle it does not pick up as quick as it should, and then when you rev it, it takes quite some time to settle down to a nice even idle - any thoughts on fixing this ?

As far as I know crank seals are OK (usually starts first kick and easily), timing is set at 2.5 degrees BTDC again as per Haynes manual - is this correct setting? Air filter is new and I have checked float height.

Needle and jet look a bit manky so probably replace them anyway.

Any suggestions to improve things ?

Cheers.

JUST GET THE CORRECT MANUAL THE MZ ONE

Interesting that if I remove the airscrew comleteley it runs really well.

Starting to think blocked or even worn jets.

Next step is to completley strip and check the carb.

I get increasingly befuffled with manuals and BVF carburation. The Haynes says 2-2.5 turns for pilot, the official 1981 says "about 1 revolution". At one point mine ran best with the official recommendation, but lately nothing makes a difference and my bike runs far too lean.


Though 30k miles is not normally any feat for a carburettor, it seems like anything past 20k miles for BVF's degrades them sufficiently to require replacement or serious input of quality jets and slides etc that really are more difficult to find with the amount of cheap Taiwanese products being made for them.. And yet, my CX500 has 75k miles on the original carburettors which are far more complicated and a pig to even understand and they're still fine enough!

I have recently come into purchase of a 30N3-1 model from a later 251 but that also has 30k miles on. It was totally gunked up sufficiently that the floats were seized solid and everything blocked up. A few hours in Lemon juice and gradual washing and work has allowed it to be a little useful and freed up, but how well I don't know.


Damn all this messing about!!! I am getting a Mikuni!!!

Carb slide looks to be a good fit in the body.

Upon close inspection the air screw is stepped / worn as is the needle.

Main and pilot jets look like they have seen better days - and one of the floats has a puncture.

Decided to replace all of the above as clearly there is a lot of wear and no way is it going to run well with a punctured float.

Hoping that will get it running better, if not then a Mikuni seems like a good idea...........or a bloody big hammer

EASY NOW BIG HAMMERS RESERVED FOR HD tool boxes