Motorcycle Repair: 88 ninja zx-10, ninja zx, zx 10

Question
my zx-10 has a problem with gas seeping into the oil, when it sits for two weeks or more.  as long as I start it regularly its fine, but if it sits for a while I have to drain the oil and there is gas mixed with the oil.  what could be causing this?  Background info, I've had the machine for four years now and have not had to do any major repairs in that time.  the engine has 24,000 miles on it.

Answer
Hi Karl,

This is common when a float sticks and fuel flows up the emulsion tower and into the carburetor Venturi. Fuel flows both directions, into the airbox and into the cylinder, where it eventually enters the crancase and contaminates engine oil.

Send me your email address as requested and I will return carb cleaning, tuning, and synchronizing information files. Send tomy email: mcso429@netzero.com

The carbs probably have varnish building or a particle of debris/rust causing the float to stick. Carbs need cleaned.

Respectfully,
Mark Shively