I've "inherited" a 1999 Big Bear 350 which has been sitting for about a year. The fuel tank was dry when I opened it up, but I don't know how it was done.

Upon initially receiving the vehicle, it would not start by pulling, and got no response from the push button start. The Neutral and Reverse lights never light up.

I have replaced the battery and spark plug, cleaned the air filter and associated box. I cleaned the carburetor, except for one jet, which I didn't want to mar while trying to extract with an improper tool. I poked a wire down into it, and sprayed it with an excessive amount of carburetor cleaner.

I opened up the fuel valve and ran fuel through it to make sure it worked properly and was truly dry to begin with, and also to clear out any debris that may have deposited inside. This seems to be working properly so I filled the tank with new fuel.

After all of this, I have jumped past the starting relay, and get the starter to turn over, but the vehicle won't catch and run.

I have two theories I'm running with -- the Neutral Safety Switch (or Gear Position Sensor) and Reverse Switch are faulty, or an issue with the spark/carb still. I have not checked for spark since installing the new spark plug, but I believe that the Neutral Switch issue would prevent it from getting a spark, even bypassing the starter relay. I could be wrong about that though.

Going with the Neutral Safety Switch, in the back of the engine on the right half I've found a stud with a male spade sticking out with a single wire attached to it, which when removed appears to be a simple brass bolt. I believe this to be the Reverse Switch. I've checked it and it has no continuity between the spade and the inside flat area. I believe this is proof that it is faulty, but I'm not sure of proper identification nor troubleshooting test.

If I look just above this I find two wires going through a rubber grommet into the engine. I opened this up, lost all my oil (which is fine, I was going to change it anyway) and saw that the wires ran behind a couple of large metal wheels (I'm an electrician, not a mechanic, so bear with me here, please.) I believe that to be the neutral safety switch.

If I am correct about these items, I need to replace them, and have no idea how to get to the neutral safety switch. Are these what I think they are? Is there a way to bypass it/them so that I can make sure that it is the culprit? How do I remove the gears/flywheels to actually get to the device?

 

First off, does anything happen when you turn the ignition switch on? If the lights, horn etc work, you may have a warning light problem, if not the fault is in the ignition switch circuit, probably a fuse, the main one is on the starter solenoid. If your problem is connected to the gearchange warning lights, they used to be simple earth connections when in the appropriate gear position, (though the circuit can be complex, with diodes and relays etc,) but most have changed to rotary switches, not sure what a 99 Big Bear has. Many wiring diagrams are available on-line, it would be worth finding yours.

 

Turning on the main switch allows all of the electrical accessories to work.

When I push the start button the oil warning light comes on, so I swapped leads to the neutral and reverse lights individually, and tested those, the lights themselves work.

Every fuse I could find is good, including the main. I checked both visually and with a meter.

What you're saying is that if I ground the neutral switch it should bypass it, correct? Have I properly located the switch?

 

Oddly enough I had an Eiger with the same problem today, turned out to be the foot pedal neutral switch, this wasn't a simple single wire to earth, but had a live feed to the switch, which is buried deep in the engine.

Anyway your problem, the engine should still spark, otherwise it would die when you put it in gear, however the "kill switch" does cut the power to the starter on some machines as well as killing the spark, could this be your problem? I wouldn't have thought it would stop the neutral light coming up though. Like I wrote earlier, a wiring diagram is a big help with finding electrical faults.