Ok my buddy has this 74 BMW 750 airhead which was left to him by a friend that had passed away. Now the bike is in fairly good condition but it sat for a while while my buddy was sick and plus a year after. we finally manned up and picked up the bike.
We have it started and running and does pretty good tooling around except i think a gasket or seal in the left hand carb is bad.

When ever he makes a left turn in he pi$$3$ fuel. We havent taken it to the BMW repair shop or taken the carb apart.

Any ideas on why it would do that.

Thanks