1. Ride or rev and idle the bike 10 minutes every 7 days or more.
In the hot summer do this every 3 days or more. In the coldest part of winter you could get away with 14 days. Some customers push their luck and get away with even 1 month. The problem with this is progressive rate build up and "luck"! How often can you eat bacon double cheeseburgers with extra mayo and fries before you have a problem?
This is a rough guide because models and climates vary so much. If you are away then you could ask a trusted friend or gardener or maid to just rev and idle the bike for 10 minutes. Be sure this person has a good understanding of motorcycles and safety. I may be able to make house calls to assist with this too.
2. Drain your carburetor(s)
First make sure the bike is in a well ventilated area away from your water heater or any place where you could be in danger of ignition, flame, heat or spark. The fuel tank can be stored empty (bone dry) or filled to the top to keep air space out. Remember stored fuel with air and heat are bad.
Step by step: Turn off your petcock and make sure it does not drip in the off position. Check this by pulling off the delivery hose. If it does drip in the off position you could clamp or pinch the hose for now. You would later need to rebuild or replace the leaking petcock. Locate the drain screw(s) at the very bottom of your carburetor(s). Most bikes have a small drain hose running from the bottom
of the carburetor to the underside of the bike.
You can direct this hose into a container to catch fuel. The other option is to put a rag under your carburetor to catch the fuel. Loosen the carburetor screw one whole turn. Once the carburetor bowl is empty tighten the screw. Some bikes have more than one carburetor to drain. Do not turn the petcock back on until you are ready to ride.
3. Store your bike with ethanol free fuel which I sell here.
The extra octane in the available ethanol free race fuel is not what we are after but it is the only way that I know how to find clean fuel here in California. The unnecessary extra octane will actually burn cooler and is good for your engine.
Race fuel is more than 3 times the price of pump gas so only use it just before you intend to store it.
You could use it all the time if you seldom ride. This is what many of my scooter owner customers do
because they also get better than 60 miles per gallon.
You could drain your tank completely or you could just run your tank as close to empty as you can without running all the way out, maybe 10 miles on reserve. Fill the tank to the top with ethanol free fuel and then ride or run it about 10 minutes to get it into the carburetors.
I can fill your tank here and I do a lot of this for my regular customers just before summer.