My yamaha 350 atv just started quitting the other day for what I dont know. The electric start wouldnt work anymore. So i had to get it home by pull start. Now thats hard to do or wont start. Thing is, when I have run switch off and key turned to off position, I get a clicking sound when I touch neg battery post, trying to put cable on. (this is after i put on positive cable). I realized its that little cylinder above battery with 3 connections. What do you call that? and is that what I need?

 

There are lots of different Yam 350s, and your symptoms are all over the place. Why did you take battery connections off? The small "cylinder" above battery may be the solenoid but they never have three connections, always two big binding posts and, sometimes two thin wires, or a plug and socket arrangement with more thin wires going to it. If when you connect the battery, with ignition off, it starts to turn the starter motor, then the solenoid has stuck, giving it a tap may free it off, but it is liable to stick again. Often a sticking solenoid is caused by a flat battery, make sure it is charged and healthy before trying to start, especially if you fit a new solenoid, or it may well go the same way as the old one. Once running check the alternator is charging the battery properly. Yams often have other relays as well as the solenoid, so your clicking round thing may be one of them.

 

Tried tapping solenoid with full charge, nothing. Tried jumping solenoid, turns over, but wont start. Normally green nuetral light would come on when tiurning key to on, but it doesnt even come on anymore. Lights still work. Turns over for 15 seconds, wont kick in. Sparks good.

 

The green light not coming on is probably your main problem. The bike has to be in neutral for the starter motor to turn, if there is no power to green light, there is no power sent to solenoid's thin wires in order to start engine. Also quite possible that a signal from this wire will go to CDI to give a better spark when in neutral, which helps starting. Sort the green light's circuit out first.

 

I started the engine by pull start, without battery, but only runs for a couple minutes then dies out. Also realized that 'cylinder" is for the winch.

 

The starter problems and the bike cutting out are probably completely separate, though a bad earth on engine or frame could explain both. If it isn't an earth, fit a new plug, check the tank vent is not blocked and, if no improvement, check the voltage across the battery with engine running, shouldn't go over 15v. If all these are correct, clean carb out. However a faulty ignition component can cause this fault, and tracing that is difficult, even with the starter working. I would sort the neutral light/starter out, then try to fix the "cutting out" problem.

 

I had it running by jumping solenoid today and battery was 14.49 while running. Does that mean my rectifier is good, cause I was thinking of ordering one. 1 thing i do notice is after I get it running it will quit if i try to go up in second or third gears, it will stall. And it will only start after I let it cool down after about 45 minutes or so. It wont start hot or warm. Will fit a new plug tomorrow. It seems like I could run it forever in 1st gear, but once I go up, its a different story.

 

14.49v maximum is fine, your regulator is OK. Your description seems like a stator fault, either power or trigger coil, but check those other possibilities out first, especially the earths. On Yams you test the trigger and power coils by checking their resistance, but I had a 600 which tested as OK, even got the Yam dealer to verify it, but it still turned out to be a faulty power coil that was causing the same symptoms as you are getting.

 

I switched back to my original ignition switch, and now green nuetral light comes on and starts by electric. Runs in top gears now too. I guess the one I ordered off Amazon was defective after a while. I only ordered it cause I lost my original Big rubber Yamaha key and the amazon one I ordered had a similar key that came with it.

 

Stick with Yamaha OEM parts, especially when it is electrical or engine related. Most of those non-Yamaha parts are complete junk. Read way too many stories of problems.