hello i have an eton viper jr. rxl 40 kids quad. It will start fine and run fine for about 5 minutes then dies and wont start again, after it sits for about 10 to 15 minutes it will start right back up and the run fine for about five minutes and dies again. i ve tried everything carb and fuel related, compression is fine and i ve torn apart the carb and check and cleaned it and made sure that fuel was flowing, it has a pull start not electric, i ve checked all my wires and they are all clean and together, but i cant figure out the problem, if anyone can point me in the right direction as to what to do, i would greatly appreciate it or any advice at all.

 

I think something in the electronics is heating up.
Ask Lynn Edwards.

 

So the first thing to check is whether you have spark when the engine is warm and not starting. The following assumes that you don't have spark. If you do have spark and the engine won't start then we shouldn't focus on electrical problems.

I am not familiar with this particular version of eton ignition system. Here is a link to the viper jr rxl40 wiring diagram:

http://www.anythingatv.com/Technical/images/WD_R40.gif

I suspect that they are using the ancient magneto points/condensor style ignition, only they are using a transistor switch driven by a pickup coil trigger rather than a mechanical switch driven by a cam. But there is not enough info in the wiring diagram for me to be sure. I've not seen one of these so anything I say is just an educated guess.

Briggs and Statton use an ignition method that may be similar. Here is a link to a description of their ignition system:

Timing is Everything - Basic Kart Ignition Explained, Part 2 - Article by John Copeland

This link starts off in part two. For anyone who wants to start at the beginning here is that link:

Timing is Everything - Basic Kart Ignition Explained - Article by John Copeland

The thermal time constant (5 minute to fail, and 15 minutes to restart) suggests something inside the engine, or mounted in direct thermal contact with the engine. External components (small and exposed to air flow) heat up faster and cool faster. If it were me (and I didn't have access to any test equipment) I would place bets that the defective component is located in the engine flywheel area.

 

i cant figure it out but there is a smalll green thing that the spark plug wire goes to and i got the motor hot and rode it around for a bit, and after it died i felt the little green piece every where i could and it was warm but not hot and when i say warm it was really all that warm but if there is anymore advice or ideas i would be appreciative

 

actually i mean it was barely above the outside air temp and cool compared to the motor

 

check your private messages and get back with us, please.......

 

Plugged pipe?

 

But the cart is still in front of the horse. Do you have spark when the quad is not starting? This is the place to start.

No sense going on wild goose chases if they can be avoided... .

 

in response to the private messages, the cdi stays cool, i checked it before and after, when it wont start i ve checked to see it there is spark, i ve seen a spark but wheni pull the pull start it may spark only once during the pull or it may spark twice, and its been both a yellow and blue spark checke with a different spak plug and it was always blue both before running it till it died and after but it seems like after running it it wont spark like its supposed to, but like before i ve checked after running it and i will occaisionally see a spark, also grabbed the spark plug boot and pulled and it gave me a nice zap. the cdi is located just under the body plastic at the front of the quad, and thanks again for the help guys and for the troubleshooting guide Jaster94.

 

ok now im not gettint spark at all, changed the spark plug and still no spark, inside or outside the engine. i tried to run it earlier and the same old process again, run five minutes then dies, and after cooldown started up again i had to go into town for a bit got back and tried firing it again and nuthing, i was gone for 2 hours and like i said no spark at all now, i know its not the cdi, because i can unplug it and it would still run, so im thinking the ignition coil (the little green thing). any more ideas guys?