....this is the "seal" on a bushed motor. Without it,
massive air leak and fuel misting will be noted.
Excuse the grounge.....this motor has been un-op for
20 years. It is a close fit, but it is not touching the case.

I do not discount the opinions of my fellow modelers.
However, I've never seen a fuel leak so bad, at the
needle....that fuel mist could be felt on the hand at the rear
of the motor. And....I might say that I've never seen a tank pressurized to the point....that it was blowing fuel out the
connections of the fuel lines.

However, I have seen engines where fuel was leaking out between the cylinder liner, and the cylinder, due to extreme
miss-torqueing of the screws....

Once again....run the motor on the bench if necessary....and
find out where the fuel is leaking from....therein lies the problem.

Dave.