ORIGINAL: Gray Beard

One of my SK .91s is doing that too but in my case the fuel tank is too far back from the engine and it isn't drawing enough fuel on the low side. It's not an air bleed carb so you aren't going to find that hole mentioned. If you fatten up the low end a little it may help but it sounds like a draw/pressure problem? Check and make sure you don't have any air bubbles in your fuel line, if you do it could be a hole in a line or a loose bung. It's just something simple that you haven't located yet. It could even be the glow plug cooling down. The temps are starting to drop now and I'm starting to have to fatten up my engines already. My engines are tuned for 100+ degrees and it has been in the 40s at the field in the morning, that's a pretty big drop so I'm opening up the needles a click at a time until the weather gets stable again.