I got a free (neglected really bad) 250 2 wheel drive AC and it had a no start condition. I found the electrics to be thrashed beyond belief and the story was (as it always is) "it ran and then just quit". Well, come to find out the battery was obviously connected backwards and the main power wire was grounded out causing melting of the hot wire and also the keyswitch is broken (still seems to work but no key) and the keyswitch cover has melting on one side. The wiring to the fuse box was messed up and so I put in a lot of TLC and got all the wires patched. Got new (used) CDI, regulator, and coil. Put a little gas in the carb and it fired right up till the gas was gone. I still get no lights on the guages but am not worried about that right now. Couldn't get it to stay running or pull gas through the gas line so I pulled the carb, has a friend clean it all out for me and now it starts, choke engaged, but will NOT stay running if I release the start button. It's as if you pushed the kill switch. You can even rev it pretty good but I only let it go for a few seconds since I don't want to kill the starter motor. Why would it do this? The switch seems fine and operates normally but it was apart and had some corrosion on it. I cleaned it all up but still had the same problem. I pulled the plug on the start switch and used jumper wires to start it. Same thing-as soon as I release the starter wires it dies but it will not start if the ON switch is off so I know it's at least partly working.

I have three theories on this but maybe someone can give me more insight.
1. I only used a jumpstarter to run and crank it. (I got a new battery but had to fill it and charge it so can't fool with it till tomorrow)

2. I have the carb wide open (no intake tube or filter box connected since the rubber tube is torn and I have it cemented together to repair it) So maybe it's running way too lean? Probably not, though, seems like an electrical issue

3. the starter is bypassing the ground that is affecting the kill switch (just a guess)

Any ideas would be appreciated

 

Try just hot wireing the key switch, and kill switch. Just use jumpers. Id focus on the key switch, as being bad, until you can rule it out, by bypassing it.
If youre jump starting from another source, just make sure the donor vehicle isnt running. You only want 12.6 volts max on the starter. If the donor vehicle is running, and that vehicle has an alternator, it can easily send 15 volts to your quad...which makes the life of things electrical kind of short.

 

SOLVED--- I did those things to no avail. I then realized that a jump starters electrical wave is really unstable and with no battery the voltage can jump all over the place and also the current they provide isn't very good for open loads. So I tested my new battery which was perfect at 12.8v and installed it. It fired right up! Put some gas in it and got the idle set and ran it for a few minutes. Reverse light works so the neutral light is probably just blown. Ill check it later. It moves forward and back seems to click through all the gears so it looks like this "free" 4 wheeler is going to be pretty fun. Now I just gotta strap all the wires and hoses up, add a fuel filter, spray a little paint on the rusty spots, put all the plastic back on and it'll be on the trails. Sure is nice when a plan comes together.

 

You might consider running a strong concentration of sea foam thru it for good measure too.

 

Gotta love the internet....10 year old thread just fixed my problem. Thx fuforums