RE: Question about gas to oil mixture........
Just like any glow engine if it blurbles then quits it has a fat low end, same with a gasser. I always go a tad fatter on the high end because the engine does unload in the air and you can go lean. The carb has a diaphragm inside that is the pump. There is also a very small screen inside that is a filter. If that screen gets crud in it then tuning the engine is always going to be a mystery. I got my G-62 in a trade and it had been in a crash. I cleaned the carb then fired up the engine and couldn't get it to run for beans?? I opened the top and that screen was packed full of nasty. Cleaned it out and it went into tune very well, two flights later and it ran for beans again. Got home and opened up the carb again and it was packed with crud again, not as bad but enough to mess up the tune. I also went to my local lawn mower/small enging service shop and bought the new carb kit they now make for this gas they are selling us with alcohol in it. Alcohol and rubber don't mix well!! If by chance you decide to rebuild the carb buy a can of the spray carb cleaner and make sure you blow out all the passages and jets!! The carb cleaner does a good job and I had a lot of crud in that carb. All is working well now.
I did find a Walbro site that has some good prints of the carb break down, ones that you can really read!! It helps a lot when I need part numbers. Nothing inside these carbs that most anyone can't figure out if you need a rebuild. Very easy!!