When i fuel up, fuel comes to the carb before spilling out the muffler. Engine is mounted 135 degrees and will be inside a cowl, so it was suggested to let fuel come out muffler when filling.. Does this sound problematic? I stop fueling when i see fuel in the carb line and dont prime. Wondering if this is related to tuning issues.

close the throttle when you fuel up.

Ok, so it sounds normal?

is the carb lower than the muffler? you can always use hemostats to pinch off the line to the carb

Muffler is much lower; dont care about what happens when fueling just want to make sure its not drowning engine when flying.

A sure cure is to use a fuel filler valve. Great Plains has a good one. The only place it can come out when tank is full is muffler. Some have said they can be troublesome but none have to me and have used them many times.

gaRCfield, are you using a three line tanK?

I did have a 3 line system. Today it seemed to run just fine (still gets fuel to the carb line before coming out the muffler though, but I guess that's ok) and I sold the plane - will exchange plane for $$$ tomorrow.