I feel like I have been down this path before. I have ryobi conversing (previously a 725 weed whacker) with a zama carb that I had mounted on a test stand and found it hard to start. The culprit turned out to not enough RPM at start up. Once I was getting enough revs-the engine started easily.

Since then I have mounted it on my big pink and have no luck starting it. Not even a pop. I can see a spark when I hold the plug outside of the engine and ground it, and I can get fuel to flow and I have primed it by squirting sam gas into the cylinder or by sucking some gas through the primer bulb valve. I'm just sort of surprised that I get no ignition at all.


I only have two guesses of what might be happening- the gas is not recent (although it does start up in my weed whacker) and it is cold outside (about 40 degrees).

Anyone have any clues?
Thanks,
Steve