125 SM Fuel problem

[drewshki]

Hello. i recently brought the bike out after a long period without running it.

It cranks well. There's a good spark but it wont fire.
The sparkplug is always dry, even after a long time cranking it.

Could it be no fuel getting to the chamber?
Should i take the carb apart?

[stephendacosta]

Sounds like a plugged primary jet. Next time drain the float bowl for storage. keeps the green scum away.

[DAVID THOMPSON]

when the 125cc mz set the carb dries out
and on mine the cranking does not seem to prime the carb
remove it and clean
then try it
if that does not get it going try
raising the carb slide and use a hose to get some gas past the carb into the intake
it needs to be very small to get past the slide needle
it will run a few times on loads of the rich fuel then it should go ok

where i live i can get fuel with no ethanol its 90 octane and the bike loves it
its found here where the boaters fill up
dave

[drewshki]

Tomorrow, going to crack into this carb when it's light.

When you say clean, do you mean completely disassemble the carb? Or are there certain areas i should not touch.

Thanks for the advice.

[drewshki]

OK, the sun came up.

So i've disassembled and cleaned the carb. The main injector seems completely clear, i can see light through it while looking down the length, i can blow through the fuel intake area, the fuel pipe is also clear, the fuel filter is clean. Still wont start.

Once reassembled i realised my overflow hose is not routed correctly. instead of running from the base of the carb upwards to the top of the lower housing on the carb, it runs straight downwards. If you open the overflow valve it just pours petrol. I assume since this is called an overflow pipe then the screw on that nozzle must need to be left slightly open. In my carb it's tight closed because the hose is routed wrong. Could this be the problem?

Really apreciate the help. Thanks very much for your advice.

[DAVID THOMPSON]

if the screw is the one on the left side at the bottom front it's is the float bowl drain
and is closed its hose should run straight down so the crud can run out when you open it
lean the bike to the right side when you open it to drain the float bowl

i do not think your getting any gas into the engine
also holding the hand throttle open when trying to start
does not help as it interferes with the motor drawing gas from the carb by reducing the vacuum it pulls when cranking
DONOT use any type starting fluids just gasoline
dave
till i learned the drill this thing was a pain to get started after sitting for a while