Oil contaminated with gasoline

My dad's bike has a problem with leaky needles and seats in the carbs. I just changed his oil and put new in. I re-used the old filter because we didnt have another one. Well guess what.. the carbs pissed gas right back into the crank case and now its all contaminated again. I supposed a petcock that just had "on" and "off" would fix the issue for good.. but what about the oil? Castrol GTX is 25 bucks a jug at orielly's. I figure gasoline weighs less then oil so wouldnt it all just float to the top? is there any way to just siphon the gas off the top of the oil?

im pretty sure the gas will just dilute the oil, in other words they mix, and it will thin out the oil

A petcock that turns off won't really solve the problem. Your issue still lies in the needles and seats. If they are not sealing your fuel level will be off even when bike is running and will cause your bike to run poorly. And the oil will be diluted and needs to be changed again sorry! Went through it myself so I know how frustrating it is.

jonarmstrong wrote: A petcock that turns off won't really solve the problem. Your issue still lies in the needles and seats. If they are not sealing your fuel level will be off even when bike is running and will cause your bike to run poorly. And the oil will be diluted and needs to be changed again sorry! Went through it myself so I know how frustrating it is.

+1
Drop the carb bowls (you can do this with the carbs still on the bike) and clean the float valve needles and seats with Q-tips & carb cleaner. Then test to see if still leaking (clear tube test should show high for a leaking carb). If they are damaged to a point where cleaning won't stop the flow - replace them. Regarding the petcock - if it's a vacuum type it shouldn't allow fuel to pass through it when the engine is shut off. If it does, check the diaphragm for holes or tears and make sure it's operating properly. The float valves still must be fixed, but the petcock should have prevented fuel flow when the engine was turned off. When fully satisfied that the leak is fixed, change oil & filter. Ed

Here's what I use to make dropping carb bowls easier...
kzrider.com/forum/3-carburetor/509690-carb-bowl-removal#509694