Motorcycle Repair: oil in the air filter, suzuki intruder, bike bandit

Question
I resently changed the oil in my 1500 Suzuki Intruder.(4.5 qts w/filter) Shortly after I decided to change the spark plugs and air filter. I noticed oil in and around the air filter and housing. Is this normal?

Answer
Hi Marvin,

A bit of oil sediment in the base of the airbox is normal.

Sometimes this is an indication of an overfilled crankcase. combustion blow-by gasses pressurize the crankcase and oil vapor flows through the crankcase vent en route to the airbox. Some oil accumulation is the result of this. Check the airbox fluid drain catch tube. Drain this tube as necessary.

Sometimes this is an indcation of varnished carburetors. Needle valves can varnish and stick, causing fuel to overfill the float bowls. Fuel rises into the carb Venturis and flows rearwards into the airbox and forwards into the crankcase via cylinders.

You'll have to investigate the cause. If the carbs are varnished, the engine may not start, or may only start and run with choke.

Clean airbox with brake spray cleaner and paper towels or other materials. Monitor the airbox and drain tube more frequently. Have a local tech check it if it continues or the amount is excessive.

I recommend the service manual to assist you with maintenance and repairs. It'll pay for itself with the first work you perform. Find manual at: "www.bikebandit.com" and "www.clymer.com" See michrofiche parts views at Bike Bandit.

Respectfully,
Mark Shively