MZ/MuZ Riders

Strange, but after a short lay up the ETZ250 it refuses to start?

Spark is ok and I've removed the carb (Bvf 30-n-3 1) and blown it through twice now but on refitting still will not fire.

There seems to be very little (if any?) fuel getting to the plug area as after several minutes of kicking the started, removal of the plug see's it 'dry' - all appears well otherwise to the best of my knowledge. Float bowl itself has fuel in when removed just the plug remains 'dry' and obviously wont fire.

Any suggestions?

Andy

Pull the fuel pipe off, turn the tap on and see if you have petrol running out. If not dismantle the fuel tap and clean inside. If you have fuel from the tap, the float needle is probably stuck, again dismantle and clean.

Sorted - well sort of!

Fuel tap/flow was ok as was the float needle - after three stripdowns of the carb I was confident(ish) that all was ok but still no sign of firing.

So, up to the top of the street and pushed it down the slight incline, bumped it and kept on pushing and after about 100yds, reluctantly it fired, very very roughly with full throtle and barely 1400prm showing. I tried my utmost to prevent it stalling and gradually after about 90 seconds of this spluttering, gradually came back to life and settled with a respectable gentle tickover (about 1200 rpm)

Running is another issue now though, if I give it plenty of throttle is picks up nicely BUT just 'tickling' it with low revs feels uneven and spluttery, like it has a misfire being the best way to describe it.

Any ideas on how to simply set up the carb as the Haynes it vauge at best!

Andy

Have you still got the rubber sleeve on the carb cable ( part no.1 fig 2.2 page 74 haynes manual)? If this is missing it can cause an air leak, disrupting the carb. It can be sealed with insulation tape.
Check your timing, the state of your points, and condenser. If you have a large spark when your points open on turning your engine over you will need a new condenser.
A duff or flat battery can give some odd running problems, having a spark at the plug outside of the engine, is no garantee that you have one inside.
Have you checked that the choke is not on, fraying inside the cable can prevent the choke from closing fully even when in the closed position.
Try blasting carb cleaner through the various orafices in the carb body. ( Take care some ofthem can squirt back at you!)
Of course it could just be that you need fresh petrol in the tank.