Sudden problem

[mybike]

Lickity split start with pedals. No start with pull start. Runs fine.
Any help would be very appreciated.
Thanks for reading.
Mybike

 

[GearNut]

3 guesses from me.
1: Pull start is not actually turning the engine over.
2: Weak ignition system will only fire when the engine is turning at higher speeds than what can be attained with a pull start.
3: Low compression.

 

[mybike]

Thanks gearnut.
As for no 1, rope does turn engine. (48cc starfire chrome)
as for no 2 i have been wondering about that.
As for no 3 my fingers, hand and arm believe the compression is good.
While i waws eating a corndog i started thinkng this problem started after i filled it with gas this last time. Mixture should be 25:1 synthetic.
I think i'll drain tank get new mixture and see what happens.

Mybike