Where is the gas reserve switch on a 2006 suzuki boulavard

You are there, try it for a definitive answer.

Unit should have a reserve tank switch. BTW, this section is for cars and trucks.

Check the reserve fuel line and the main fuel line to make sure they haven't been switched. I purchased a Suzuki Intruder and was riding all the way to reserve to check the mileage and when I ran out I couldn't start it even though I switched to reserve. Turns out that someone had the tank off to service the air cleaner and had reversed the two fuel lines so the fuel valve was running the bike on the reserve tank tube. so when I switched to the reserve position it was hooked to the taller brass tube in the tank and the gas level was already below it. The tanks just have two brass tubes, one taller than another so gas cannot be sucked below the taller tube when on main and then when switched to reserve it sucks from the shorter tube allowing the remaining gas to be used.

10\40 sythetic

had same problem with a suzuki savage...my fix was to tie two overflows together with a t joint...
..its an airflow problem of some sort... also, some bikes have to run on reserve or prime always...its not a perfect system

With the age of your machine , you should drain the tank and remove the petcock. If you can take it apart rebuild it. If you have no reserve , either the reserve tube is broken off or the petcock is plugged. It is possible the four hole washer the seals the the lever and diverts the fuel is damaged , worn , or broken. Depending on the over all condition of the petcock replacement of the entire unit may be the best option. At any rate an new fuel petcock would definitely fix this issue. Rebuilding your old petcock is only an option if all the parts you need for it are available.

fuel lever should be set to on. When you run out of gas in the on position then you switch to reserve. Turn the gas valve to off when not riding

Do you have a petcock on the bottom of the gas tank? If so, if you have a "reserve" the petcock will have three positions, off, regular and reserve. If you only have a two position petcock you have no reserve function. Petcocks work by taking the gas in the petcock tube higher up in the gas level, once the gas level drop below a certain level on the gas tank pickup tube, the petcock has to be switched to reserve where the tube picks up gas at a lower level. Hope this is not too confusing.

located on bottom side of gas tank. should be inline with filter usually left side location