Electrical problem
 

I recently bought a 150cc chinese atv fixer upper. After replacing many parts, I got it to run. However wires going into the junction of key switch wires started smoking and melting and the fuse on the positve battery cable blew(it was a 30 amp fuse). I repaired all the wires and replaced the fuse with a 15 amp. Now it won't do anything. Won't even turn over. Can someone heip?

The key switch had an internal short, did you replace the switch?

It is a brand new key switch and worked flawlessly until it ran for about 20 to 30 seconds.

Yes but it melted your wiring loom, and may have burnt out the CDI too. Get another new switch, make sure it is the right one and wired correctly to your loom. There is usually a live from fuse, and an earth going into them, if those are shorted together you get a blown fuse and/or melted wires.

Thanks, I'll do it.

At a loss
 

Ok, I replace the key with another an hit the start button with a big fat nothing happening. So, I decided to Jump the solenoid to see what would happen. It fired up and I let it run for several minutes and then killed it. Tried to jump the solenoid again and nothing happened! I tried to start it many more times within the next couple of hours and got it to run two more times. My question is why is jumping the solenoid only working intermittently? Any help will be appreciated.

Seems like the starter motor is on it's way out. They often get "hit and miss" when the brushes need changing. That is why I always check the starter circuit with a test lamp when fault finding.

I don't think the starter is going bad. When I attempted to jump the solenoid many times there wasn't a spark from the jump. When there were sparks from the solenoid terminals, it fired right up. I checked the ground and it seemed good. I don't think (1) power is getting to the solenoid all the time and (2) the solenoid needs to be replaced. Any thoughts?

No. Get a test lamp and connect it between battery neg and positive post on starter. Short solenoid, if the lamp lights but starter doesn't turn, faulty starter, try a few times, this is an intermittent fault. Only proviso, the engine could have a bad earth, so check by connecting the test lamp to pos on battery and a clean, unpainted piece of engine and see if it lights. If lamp doesn't light, in either case, faulty lead between battery and starter.