hello I recently picked up a couple atvs that need work. they both have gy6 motors one is a 150 and the other a 250

I have two questions:

on the ignition switch i am missing two wires on the harness.
i wanted to try and figure it out rather than buying a new harness

i have a red and black
anybody know where the other two should go?

second, are the gearboxes interchangable between the 250 & 150?

thanks

 

I doubt the gear boxes would be compatible. Those are two completely different engines.

Re: Ignition switch wires:

The standard generic chinese ignition switch contains a 12 volt "power on" switch, and a separate kill switch which closes when the switch is off. If you have a DC powered CDI then you don't need a kill switch. So I suspect that is the case here. So the other two wires from the ignition switch could be left unconnected.

So why are you asking the question? What problems are you having?

 

the 150 i have isnt gettin spark. i think the cdi is missing a wire which i asssume goes to the ignition switch/key. the other missing wire off the key i dont know where it goes.
this is on a 2006 sunl 150

the 250 i have is a wilderness 250 and i got it with the gear box completley disassembled. i have a spare 150 gy6 that needs a crank and i was hoping to pull the guts off the gear box out for the 250.

 

 

 

I have no idea on the gearbox, except to say that I don't see any reason why parts from two different engine designs would be compatible. It would be like expecting a mazda transmission bolting into a ford and working. Did someone tell you this would work?

On your 150cc with no spark:

Do you know if your CDI is DC powered or AC powered?

Looking at the following picture, what wire do you think is missing at the CDI?

 

Missing the kill switch wire. Is that one that goes to the key switch?
Any idea which one?
And where would the other missing wire go

 

From your description I suspect that you have a DC powered CDI, and you are not missing any wires.

Unplug the CDI. Use a meter to measure the DC voltage on the "AC Ignition Power" pin in the wiring harness to ground (as denoted by the picture posted earlier) when the ignition switch is on. If you have 12 volts DC that verifies that you have a DC powered ignition. And it also means my picture is misleading since the pin should be labled "DC Power". Most quads have AC powered CDIs, but DC powered CDIs are becoming more and more common.

If you don't measure 12 volts DC, then switch your meter over to AC volts on the 100 or 200 volts AC scale. Measure the AC voltage to ground in the wiring harness while cranking the engine. If you see 40 to 80 volts AC then you have an AC powered CDI.

DC powered CDIs and AC powered CDIs look identical. You cannot tell by looking which is which. An they are not interchangable. You need to measure your wiring harness as outlined above to see which you have.

The no spark troubleshooting procedure is different between the two CDIs. Lets find out which CDI you have then go from there.

Some background:

On quads with AC powered CDIs the ignition system runs entirely on AC voltage generated in the stator when the engine is turning. There is nothing in the ignition that depends on the battery voltage. The only thing that the battery does is turn the starter motor so the stator can generate its own separate power.

On AC powered quads the ignition switch has two switches. The first switch is closed when the ignition switch is turned to the "on" position. This allows the starter to be activated through the safety interlocks and the start button. But once the quad is running how do you shut it off? The second switch in the ignition switch assembly closes when you turn the ignition switch "off". That ground the kill switch pin on the CDI, killing spark and shutting off the engine. Without this second switch the quad would just keep on running when you turned off the ignition.

On DC powered CDIs when you remove the DC power with the ignition switch the spark stops and so does the engine. There is no need for the separate kill switch section in the ignition switch. Those two connections are extra and not used. And there often is no need for the kill switch wire at all at the CDI. So that wire is missing too.

I hope you are beginning to see why I am thinking you have a DC CDI ignition system.

But please do the test to see whch CDI you have. It is easy to do and may prevent us from going down a blind alley to to wrong assumptions.

 

I still think I am missing wires bc my ignition switch/key only has two wires goin to it. Black n red. The harness has a place for four pins like all the other chinese atvs I have messed with. There has to be more than two wires on a ignition switch, right?
I will test the cdi today

 

I started to think about testing the cdi as you stated but I don't know if I can. Nothing happens when I use the start button(assuming it's bc missing wires on the ign switch harness) so I have been trying to start/get a spark by jumping the starter. Will I get a reading still?