Hello,
I'm a brand new member, I have a 150cc ATV that was running great until last night. Guess I shouldn't have pressure washed it. There is no spark, I changed the ignition coil and wire and plug with NGK, still no spark. Also, the battery was dead this morning and have since purcahased a new battery and fully charged it as well. I do have some mechanical apptitude and can use a multimeter just looking for a place to start and some schematics would help too.
Please help!
Thanks,

 

I would check out all the wire connectors plugs and make sure they are dry and i wonder if water messed up the voltage regulator? when i had 3 china qauds i used a ton of electrial grease on all the wire connectors (plugs) and also used liquid electrical tape on them all to seal them up and never had a problem with water. alotof the electrical parts on these machines are not water friendly.

 

OK, I'll try that, I also checked the handlebar mounted kill switch and the green wire is grounded, which I think is normal, but the black and white wire is also grounded which I think is the problem. This is with the switch disconnected and the wire ends are free. How do I test the CDI box?

 

A Black/White wire is the classic color for a kill switch wire. It should not be grounded. No need to look at the CDI yet, a ground on the kill switch pin of the CDI will prevent spark. That has to be fixed first.

Disconnect the black white wire at the CDI. Does the quad start now? Important: Make sure you can hook that wire back up quickly to kill the engine in an emergency, and note there is normally high voltage (more than 100 volts) on this line, so you can't do this with your fingers. Have some insulated pliers or a clip lead standing by.

My 150cc quad has 3 kill switches:

Ignition switch: One pole of two shorts the kill switch wiring to ground when the ignition switch is turned off. This is what stops the engine when you turn off the quad with the ignition switch.

Tether Kill switch: A cord pulls off a plug which shorts the kill wiring to ground. The plug holds a switch open (no connection to ground) when installed, allowing spark. [To disable this switch simply disconnect it. Don't short the wires together - that kills the spark - not what you want to do.]

Left Handlebar Kill switch: When clicked this shorts the kill wiring to ground. On many quads there is a two step process to reset this switch. You must place the switch in the middle position, and then push in (towards the handlebar) until it goes *click*. Anyone who has ever had this style switch has been had at least once by neglecting the "click in" part.

Here is a wiring diagram of my 150cc quad. There wasn't any available diagram when I bought it so I traced out my own:





So why was your battery dead? Is your charging system working?

 

Welcome to the forum Malamute !

It looks like LynnEdwards and hoytultratec have given you lots to check out..Let us know if you get it figured out...

 

Hello all,
I just want to say a super huge thanks to everyone who offered assistance, especially LynnEdwards who posted the wiring diagrams. I disconnected the Black white wire from the CDI box and sure enough the little guy had spark again. Now I'll look to see what is causing the "kill" ground. The handlebar switch is completly disconnected so that is out of the loop, I don't know if there is a tether kill switch, I haven't found one on it. Are they usually on the handlebar somewhere?

 

You may not have a tether kill switch. Mine is mounted right on the front left plastic fender. Mt neighbor who supposedly bought the exact same quad as me doesn't have this switch - instead there is just a hole in the fender where it goes.

You may have a pinched wire somewhere that has grounded this wire to the frame.

 

I pulled the ignition switch out and checked it out. It had corrosion sludge on some of the connections. So I disconnected it and hot wired the power and tried to start the quad. Lots of spark and it almost starts but it just won't run. Should I try a new CDI box?

 

IIf you have a blue spark your most likely OK...If the spark is yellow it might need replacing...With spark it should run...Are you still using the stock spark plug? A NGK C7HSA is a good replacement..

 

Yeah I put the NGK plug on, still no starting, nice blue spark though. Filled the tank with gas just to make sure, pulled fuel lines to make sure there was fuel getting to the carb. I just wondered if maybe its firing at the wrong time because it sounds like its close to starting. It will even "pop" if you give it too much gas when cranking.