Saito FA100 running problems

Glad you have solved it. Glow plug is first check obviously, and if you have not fiddled with carb jets or at least if you have put them back to factory settings and start from there although usually only the main jet needs tweaking depending on temps and humidity. Then go for fuel I think that the fuel once opened loses it's kick due to being out in the sun's UV. I now surround my fuel can with insulation silver foil and had no problems since... Broke my heart having to dump half a can of fuel at £28 a gallon and buy some more but that is minor compared to going up the field and the flipping thing not running right. Been there and done that!

Yes very frustrating and fuel is expensive enough. Luckily was nearing the end of mine so not so bad.