Motorcycle Repair: Yamaha xj1100 1983 fuel / tank problem, gas tank liner, frequent cleanings

Question
On that byke, there is one fuel switch lever on each side of the tank marker, ON, OFF, PRI, and RES.
What is the normal position for driving? When I turn it at ON the byke backfires, when I put it on PRI it's OK but there is some fume coming out from the motor head. That byke has nmot been out for about 9 months until I buy it. I had the intake manifold adaptors changed because they were cracked. Also there is some blue smoke coming out of the exaust when it revs up. Also the tank seems to be rusty inside...
Thank you.

Answer
Daniel,

Normal position for riding is "ON" position. "RES" (Reserve) is used when you run out of gasoline while in the "ON" position. Allows you to get to a refueling station. "OFF" is used when not riding and during periods of storage. "PRI" is used to refill the carburetor float bowls only after rebuilding the carburetors or after carburetors have been drained of gasoline for strorage, etc...

Blue smaoke is oil burning during the combustion process.

Fumes from engine may be from a variety of causes.

Remove the rust from the gas tank and seal the tank with a product such as "Kreem" gas tank liner, or similar product. Rust particles will cause performance problems and require carbs to need frequent cleanings.