It will run longer after each successful start until it does get over the hill. Then it runs perfectly smooth and idles just fine. If I turn it off when hot I still need successive attempts to get it beyond a starving condition. It will never start with the choke on. I must alternate choke/no choke and get the start on the "no choke" pull on a massive yank. There appears to be an initial inability to get gasoline into the cylinder that is slowly being overcome. Can pressure be leaking into the carb and be stopping the flow of gas? There's pressure into the carb from the inlet tube on the back side, and there' gas in the carb when I remove the air cleaner and look in. Valve issue that temperature is dealing with?
Have drained the oil to see what that looks like. Not bad looking, no smell of gasoline, but it did come out rather easily and felt like it may not have much viscosity left. Replaced it. Runs about the same. I've had the carb apart twice now and soaked it in lacquer thinner and gave every port a good needle "reaming". The last time the engine was running it was idling really well when hot, so I decided to play around with the needle valve setting. I had it set at 1+1/2 turns out. Amazingly, turning in or turning out had no effect on idle. I could shut off the needle valve completely and it would still run the same. I could open it up all the way and it would still run just the same. I could not kill it. Would assume that indicates that there's a seating problem there, and that I'm likely running partially obstructed even if I can get gasoline and air flowing through it very easily when it's apart. I noticed something else also. When the engine is stumbling to get going at first, the gas tank appears to somehow get pressurized, because gas is being pushed out around the cap. The only way that can happen is if the carb is managing to vent off into the gas (?), which would appear to indicate that maybe the valve isn't always seating well. I'm suspicious that my carb is fighting against a back pressure coming from the cylinder and is not drawing well and can't overcome it at first. I changed the spark plug and let the engine run on high for a good half hour. When I examined the plug it looked fine to me. There's absolutely no smoke in the exhaust and it doesn't appear to be burning any oil. Still, it's almost impossible to get going. You cannot ever start this engine with any amount of choke on. I'd love to replace the entire carb, which sells on eBay for about 20 USD. Unfortunately, I can't anyone who will ship to me in Canada. I called into the local parts warehouse, and they quoted me $204 here. That's highway robbery. I'm hesitant to use the engine now if it has the potential to maybe cause real problems, but It doesn't seem to be hurting anything when it's up and running.
