2 months ago, I was riding the sunl 150 and my 2 boys each had a 90cc sunl. 1 machine made a loud pop when we were riding and then died. It has never seen the light of blue spark since. The dealer has been very accomodating, long delivery lead times but cooperative with parts. I have been through the following list of items and have replaced them all with new parts. Still, no spark. The dealer is now thinking of sending me a whole new motor "Assuming" it could be mechanical in the chain for the magneto or something?????

Anyway, I've replaced the following items:
coil, plug, CDI, harness, alarm remote stop box thing, magneto, handle bar kill switch. All connections are basically new due to so much being replaced. But still no spark. The dealer said a dead magneto hub for the magneto is a last ditch attempt at throwing a part at my son's ATV that he has not ridden in over 2 months.

Can anyone offer some suggestions? My poor son has had a disappointing summer not being able to ride this "spider house" that has been sitting for so long. Thanks.

 

sometimes you gotta do what you gotta do, since you have 2 sunl 90's the best bet is to start exchanging parts from one to another until you find the problem, it sounds worst than it is should only take an hour or so and its a positive way to find the problem. takes all the guess work out.

 

The dealer has sent me all new items so I did not need to swap out from the other 90. The only thing left to swap if the motor. The dealer is sending that now. Is is probable that the magneto magnet hub or the timing chain could be causing this? As I mentioned, I put in a new wiring harness, CDI, coil and everything else electrical. Even the kill swithc on the handle bar.

 

Just bought 2 110cc SunLs myself , hope I don't have to go through that I know how frustrating it is. Here's an idea (don't know if it will work, but worth a try). A long, long time ago I had a moped and one day the thing just died. My Dad thought I had put to much oil in the gas mixture and tried draining it and put new mix, nothing. It would crank but would not start. After changing numerous parts and a couple of months gone by, he finally figured it out.
It was a burned out light bulb in the tail light. It had a continuous line of electricity and when the the bulb blew the line of current was broken and would not start, i know it sounds crazy but it's the way it was made.(I believe the brand was Tomo or Tomos) Anyways, don't know if that helped but it might be worth keeping in the back of your head, these China atvs are a little crazy.

 

the poster above reminded me of my brother buying gas for my motorcycle when I was younger. bike ran great, then put more gas in to ride one day and nothing, it would not run at all, after all the trying dad came home and after a few min said who bought this??? my brother had helped me out alright, he bought me kerosene instead of gas!!! nothing to do with yours but it is funny anyway.

 

had a firing problem on my daughters sunl 90 and after putting new firing coil and cdi box it turned out to be the pull off kill switch in the rear had messed up. i unplugged the harness to it and it fired right up.