not quite F1 bout you can probley help me!

[madmat666]

ive got a MZ etz 125 motorbike its a 2-stroke commuter thingy, bit porley
it used to start alright, i would warm it up on the patio and switch it off probley once a month before leaving it under its cover. tried to drive it to the mot station started ok, i rode it across the road at which point it stalled and has not started since just doesnt seem to want to fire
it gets fuel
there is a spark
electrics seem fine
piston is going up and down
there is no air filter could this be the problem?
dont think i flooded it
could be the carb, took it apart found some of creamy white scum in the chamber at the bottom dunno whats thas doing to it
any advice would be much appreciated

i recentley bought and installed a clutch cable, is there anything i could have done to it when i installed that?

thanks in advance
matt

[Rhino]

it could be your petrol gumming up. How long since you put fresh petrol in?

[madmat666]

not long, took the fule line off to check there was fuel getting in and it looked fine

[JGM]

I had a two stroke Suzuki T500 once which WOULDN'T start despite all the usual suspects apparently being in working order. Eventually I found out that the exhaust pipes had become so clogged up with oily deposits that they were preventing the engine from breathing because of extreme constipation. I took the silencers off and it started first time and ran perfectly. All I had to do then was to clean the silencers out.I don't know if the MZ has an easily removable silencer but if it has take it off and give it a go.

[ISK]

Two strokes can be very susceptable to spark plug gremlins, you'll get a spark if you take it out and test it but under compression it won't fire....try putting a new plug in.
Rhino's point about the fuel is another good one. If the fuel has been sat in the tank for a while, the more volatile compounds evaporate away, in effect making the fuel less flamable. We use a portable standby generator, it used to get tested about twice a year and would never start unless you filled it with fresh fuel. It was cured by sticking some tape over the tank breather hole. Now we just pull the tape off and it starts first time every time.

[boyracer]

Agree with JGM, blocked exhaust could definitely be a problem, though would have thought it would still start.
White scummy stuff in carby bowl would sugest moisture or at the very least the fuel starting to break down. Replace it, even if you think it's alright.
Check for spark, not just once, keep checking.
Had motorbike with CDI (capacitor discharge igniton) that would start run for short while then just die. Try to restart immediately and wouldn't go, come back bit later and no problems.
Closer investigation, with spark plug out and grounded against the cyl head, showed that the spark started off bright and the more times you kicked it the weaker the spark became till it just wouldn't jup across the spark plud at atmosphere pressure, let alone the pressure in the combustion chamber.
Does your bike have a battery ? Yes I know most don't need it but there are a few silly systems out there that use voltage from the battery to excite the igniton or pick up coils. Don't understand it though have seen it happen. Generally once they are running the magneto supplies the voltage to excite, so maybe not your problem.
Did bike just stop ? Stalled it ? If it spluttered, suspect fuel. If it just died suspect electrical.
Hope thats helped you out, let us know if you get it running.

:confused: Airfilter hasn't disappeared into carbie throat blocking off air has it ?