stumped and clueless HELP

[Skyliner70cc]

Its probably the fuel if your spark and carburetion are good. 5 deg F and high octane fuels doesn't mix. The higher the octane the harder it is for the fuel to vaporize, particularly at colder temps. Couple that with the fact that most folks use excessive oil in their mixture and you have a recipe for hard starting.

Recommendation: use lowest octane fuel possible. I use 85 octane w/ zero problems. Use 40:1 oil in your mixture.

Also:
a. Remove wiring for kill switch to rule it out.
b. Those factory wire connectors to magneto are awful...I hardwire (solder and heat shring my connections after having them come loose causing intermittent ignition problems).
c. Remove spark plug and pedal bike like crazy to blow out any oil/gas mixture stuck in engine. If fuel isn't vaporizing properly, it'll pool up in the crank and quench the spark plug on start attemps.
d. Use a heat gun and heat up your engine head and carburetor. This will help a bunch and what I did when my bikes had issue starting in temps below freezing.

 

[adam valentine]

but its inside in 70 degrees until just before i try to start it

 

[srdavo]

but its inside in 70 degrees until just before i try to start it

you are still pulling in cold air (outside temp) to the fuel mix.

 

[motorpsycho]

yes, even tho the engine is warm from being in a 70 degree building, the carb is sucking in 5 degree outside air.
engines do run a lot better on cold air, but, getting an engine started in cold air is something different.
why not try starting it in the 70 degree building???