Yamaha YQ50 Aerox Backfiring & Not Starting

[carlhorn]

Hi all,

Last nite, I left my house and as I was going down the road the Aerox started to backfire. It didn't do it for about 15 mins. I then filled up with normal unleaded and about 2 mins after filling up it started backfiring like mad. It then started to die on me. I was using full throttle but moving at about 5mph. It then cut out on me completly and I haven't been able to start it since. I have changed the spark plug (the correct one) and have got a Haynes Scooters Book but theres not much in there.
Can anyone else help me??

Thanks alot,
Carl

 

[Astrolopitec]

The spark plug wire or boot or even the coil could be bad. A short in the wires that feed the coil could do it. An excess of carbon deposit in the cylinder can also cause back fire. And a cluged jet or float valve can give erratic running. So can craked or broken reeds.
First check the spark by connecting a plug and resting it against the metal frame.

Juan

 

[carlhorn]

All done and no luck.
I am convinced its the ignition control unit.

 

[Zmod]

New spark plug? If not test a new one. Correct Length of the thread on spark plug? Clean carb. Check reed, Crank, cylinder and so on...

 

[Swobber]

It could be the ground wire.

Take a new wire and connect to both the engine and the frame.

/Swobber

 

[carlhorn]

I have ordered a new CDI unit for the bike because I have a feeling it could be the timing of the spark.
Should try it out tomorrow.
Thanks for all your help.
Will update tomorrow