I have a Yamaha Warrior ATV 350 Electric. Everything is wired up, I have already pretty much established the battery is dead, but when I jump cable it to the lawn mower i get connections/lights etc. BUT when I hit the Start button to start the engine the starter just clicks, could this be the spark plug ? I have done a spark test and Did not recieve a Spark, so I should probably go get a new spark plug correct?

 

It shouldn't have anything to do with your spark plug, the only reason you're not getting spark is because the engine isn't cranking over. It's the movement in the engine that generates the spark, so if the starter motor isn't even running, no spark.

There are a number of things it could be, most likely it's either a bad starter or bad solenoid, but it's also possible that the source you're jump starting from is too weak to run the starter motor. So first thing, i'd say go get yourself a new battery, since you're going to need one anyways. Give it a try then, and if it still just clicks, try jumping out the solenoid.

To jump the solenoid: Follow the positive battery cable down underneath the left side rear fender. You'll see where the battery connects to the solenoid, then the cable going to the starter motor connects on the other terminal of the solenoid. Then carefully use a metal object like a pair of pliers, a screwdriver, a thick piece of wire etc. to short out between the 2 terminals on the solenoid. (get somebody to pull in the clutch for you before you short it out, in case it's in gear and this actually works, otherwise it could take off without you.

Then if that still doesn't work, most likely it'll be a bad starter motor, but post your findings before you go buy another one.