Need Help with a 50cc Midwest Motors Bobcat ATV 2-Stroke. I bought it for my 5 year old for grading and it didn't have spark. Put it in my truck got someone to look at it and it had spark my tech didn't even do anything. Took it home no spark. Played around with it and it had spark?? My 5 year old drove it for about 5-10 mins (it was gutless with a 35 pound kid on it) then it died? No spark again. I switched the CDI in it because my old one wasn't passing any voltage through it to the coil? Unpluged the new cdi and hooked my meters to it it has appox 50-80 volts with the key on. when i turn the key off it has 90-120 volts don't know if this means anything? when i switch the key on and off as it pull start it, i get spark only as i turn the key on and off. I took all the tape off the wiring to make sure they weren't grounding out.

 

I haven't been able to find much on this quad. Do you have links to a manufacturers web site? Do you have a wiring diagram by chance? Is this a chinese made quad?

One thing for sure, you meter readings don't make sense. More investigation is needed here. Where did you measure that? What pins? Is there a link you can send showing a similar CDI that you used in order to figure out where to measure?

 

It is a chinese quad. I've looked everywhere for a wiring diagram and i can't find one. It did have a 4 pin cdi and i'm trying to change it to a five pin. I have five wires coming from inside the engine Black, Orange, Red/Black, White, White/Red, The black/red is going to my cdi front kill switch and my back key. The Black is my ground goes to just about everything. The white/red just goes to the CDI. The white just goes to the rect. The orange goes to nothing cause there is nothing on the other side of the connector. I'm thinking the problem is in the stator but i'm unsure how to get at it on this. It doesn't look as simple as a dirt bike. It has a belt system like a sled. The wire's im testing are the white/red and the ground. Please help

 

The five pin i'm trying to replace it with is a gio cdi

 

You had a four pin CDI and you are trying to replace it with a five pin CDI. Do these two CDI's look like the 2 CDI's in question?:




Four pin CDI's are DC powered (from 12 volts DC), while the five pin CDIs are powered off the stator with moderately high voltage AC. They are not compatible with each other at all.

The first thing to do do is see if the above CDIs are what we are talking about, or is it some other CDI entirely. Then get the correct CDI for your quad. Then wire it in.

Lets start there, then we'll have to review you previous meter measurements since they don't any sense to me at this time (but we will make sense of it in due course...)

 

the five pin one is correct. the 4 pin one is different. i'll take apic of it. how can i tell if it is dc or ac.

 

AC CDIs are powered with a moderately high voltage winding on the stator completely separate from the battery charge winding. The AC voltage ranges from 50 volts cranking to several hundred volts at running speed. DC CDIs are powered from battery voltage (12 volts DC). Inside these CDIs there is another power supply that takes 12 volts and converts it to the high voltage necessary to run the CDI.

If your CDI is DC powered, on your four wire CDI connector the power pin will have 12 volts on it when the ignition switch is on, and zero volts when the ignition switch is off.

If your CDI is AC powered the power pin will have zero volts on it with the ignition on or off, but when you crank the starter motor the pin will have 50-80 volts AC.

Your 5 pin CDI is AC powered. If you don't have the high voltage winding on the stator to power this CDI then you can't make it work in this quad. You will have to find a DC powered CDI. But first we need to find out if your existing harness is wired for a DC or AC CDI.

 

I have one that had the same thing! Finally figured it out. Towards the back end of the quad there are some wires that passed through the frame and where the did they rubbed the wire casing off and created a short which ultimately would cause the no spark condition