Just bought an 02 Bonneville that has been sitting for 2 years in a heated garage with a small amount of fuel in the tank. Any precautions other than fresh gas and battery before I attempt to start the machine?

pull the carby down and clean out the corrosion blocking the main jet

There are treatments (chemical) available, depending on the amount of water in the fuel. BTW, the caps on those tanks just don't blow off, they're treaded and screwed on ( I know this because I delivered fuel oil for 8 years).

If the engine stalls when you are going 30-45 mph, you are either running out of fuel in the carburetor or you have an electrical problem. In 1996, Harley went to a vacuum operated fuel petcock. It has a small vacuum hose running from the carb to the backside of the petcock. Over years of use, the diaphragm develops small holes. You may need to take the petcock out of the tank and take the plate off the backside. There is a needle, diaphragm. and a spring behind the plate. Hold the diaphragm up to a light and gently stretch it. Look for holes. This may or may not be the problem but it's where I'd start looking. Make sure your idle RPM is about 1000 or so.

Good Luck
Steve

Pump is probably stuck. Pound on tank with a rubber hammer or wood bat (no metal) with the key on. Pump should make a humming noise for 1-5 seconds after key is turned to on if working. Next replace the filter.

Since it's on '01, if you've never cleaned the fuel filter, start there. Remove the tank, turn it over and remove the 2 bolts holding on the fuel tap. There is a small bag like filter in there. Remember how you take it apart. There are 2 rubber gaskets (reusuable) that have to go back correctly. The '01's have a problem with a bad gas tank lining and you will find chips of paint in the filter.

I believe that the fuel pump and gas gauge are all one. They are located in the fuel tank. When they start going bad they sometimes start reading the amount of fuel left in tank incorrectly.

If you look closely there should be 2 holes in the fuel tank, also if you look inside the fuel tank there should be some remaining pieces of the fuel line and a fuel filter. If this has been sitting for any length of time you will also want to replace the fuel filter.

Now comes the fun... or a challenge

To start with you will need 2 sizes of fuel line ( go to a small engine repair shop) while you are replacing things you may want to buy a new primer bulb also.

to insert the fuel lines into the tank you will have to cut a tapered tail about 2 " long so that you can grab the fuel line with a needle nose and pull them through and out of the tank so that you can trim off the tapered tails. On one install the fuel filter and stick back into the tank, on the other trim the tapered tail off and pull the line back into the tank but leave about 1" sticking through the tank.

Now hook up you fuel lines to the carb and/ or primer bulb

Fill tank half full with fuel ... now test the installation if it doesn't pump fuel but instead you can hear it blow bubbles in the tank it is simple just reverse your lines on the carb / primer bulb

Retest if it works like it should you are ready to attempt to start it... good luck

The sputtering is likely because of letting it sit for a year. When fuel sits for a long period of time, it does go bad. It is always important to add a bottle of Sta-Bil if you plan on leaving a tank of gas sit for a long period of time. After the fact, however, one fuel injection treatment likely isn't going to clean the immense amount of gunk out. You'll want 2-3 consecutive treatments with a high quality injector cleaner (the cheap stuff is not as effective). The firing orders can be found online, but I can't dig up a link for you, but you can look it up yourself in autozone's repair guides. I would recommend purchasing the service manual for the vehicle though as the firing order and copious amounts of other invaluable information can be found in there, it's well worth the investment. Finally, after sitting that long, you'll need to change the engine oil, check the fluid in the transmission and radiator, check the condition/gap on the spark plugs and wires, and check the condition of the air filter.

The carb may need cleaned! make sure tires are not dry rotted! The seals may have dried out after a long wile but in most cases you should be alright!

Check the timimg belt, check fuel pressure, the injectors may be clogged with dried gas residue after three years. Check for spark.