[DoneMantis]

I have a 2002 Polaris scrambler 90 that has no spark. It lost spark a few months ago after I shut it off to take a short break after riding for a while and about an hour later when I tried to start it again, it would not start. It always started in the first kick so this was a bit of a surprise to me. I made sure it was getting gas to the carb and tried to start it again. After trying to kick start it for a few minutes it eventually started to puff and after a bit more kicking it finally started. I rode it around for about 15 minutes and everything was working perfectly. I shut it off with the key and took a break. After an hour i wanted to ride it again and it fired right up in the first kick as it usually did. After only 5 minutes of riding, it died abruptly and would not start back up. This is when I found that it had no spark. I tried a new spark plug and still nothing. I disconnected the black/white kill wire from the C.D.I to bypass all safety switches, nothing. The Ignition coil tested within spec and I even cut a little bit off the end of the spark plug wire and got a new spark plug boot, still nothing. I cleaned a few connections and made sure they were all good, which they were, still no spark. I tested the ohms of the stator and found that the stator was not within spec. The manual said the resistance of black to white/red should be 450 ohms but in my tests black to white/red had only 110 ohms. I bought a cheap aftermarket stator on eBay and replaced the old one with it but still no spark. I also noticed that if the engine is cranking and I hit the kill switch or key switch while it's cranking it will have one strong spark at the plug and no more. If I put the plug in the engine and do the same thing it will pop once. It does the same with the old stator as well. I am thinking that it must be the c.d.i that is faulty but I'm not sure because the stator was not within spec before I replaced it. Just to be sure that I didn't receive a faulty stator I tested the new one and it was perfectly within spec. I am about to buy a new c.d.i but they are very expensive and I want to be sure that it is the c.d.I that needs to be replaced before I buy one. Any help or advice would be greatly appreciated.

 

[micoviso]

Great description, but $30 doesn’t seem “very expensive” to me. Unless you’re only looking at OEM, and then....why?

Amazon.com : 0450722

 

[latebird]

The problem with the Chinese electrics is when Polaris mated their controls to the wiring harness, wires changed color at the controls and it becomes confusing.

On the Std Polaris, the black wire is the kill wire and the key switch performs basically two functions - when the switch is off, the black wire is connected to the brown wire to kill the spark - then the switch is turned on, the blk is disconnected from ground (brown is ground) and the battery pos (red) is connected to red/blk: one makes while one breaks and it is the opposite from one position to the other (newer and EFI models are completely different) whereas the Chinese key switch connects the battery (red) to brown (switched positive) AND connects the blk/wht and blk/blu.

The Chinese wired machine kills the spark then either the red-brn or blk/w -blk/blu connection fails (note: 6 wires to the key switch and only 4 used)

Blk/blu becomes blk/yel at the tether switch

Blk/yel is connected to black at the LH switch

Black is ground - lose the ground connection and the spark is killed
Blk/wht at the CDI unit is ground - disconnecting it will kill the spark

Remember: 905 of all ignition problems are connections and 90% of all connection problems are grounds

 

[micoviso]

The problem with the Chinese electrics is when Polaris mated their controls to the wiring harness, wires changed color at the controls and it becomes confusing.

On the Std Polaris, the black wire is the kill wire and the key switch performs basically two functions - when the switch is off, the black wire is connected to the brown wire to kill the spark - then the switch is turned on, the blk is disconnected from ground (brown is ground) and the battery pos (red) is connected to red/blk: one makes while one breaks and it is the opposite from one position to the other (newer and EFI models are completely different) whereas the Chinese key switch connects the battery (red) to brown (switched positive) AND connects the blk/wht and blk/blu.

The Chinese wired machine kills the spark then either the red-brn or blk/w -blk/blu connection fails (note: 6 wires to the key switch and only 4 used)

View attachment 145684

Blk/blu becomes blk/yel at the tether switch
View attachment 145688
Blk/yel is connected to black at the LH switch
View attachment 145690

Black is ground - lose the ground connection and the spark is killed
Blk/wht at the CDI unit is ground - disconnecting it will kill the spark

Remember: 905 of all ignition problems are connections and 90% of all connection problems are grounds

So are you saying don’t buy the Chinese electrics, or be aware of the differences and adjust accordingly? I’m sure your statistics are accurate when human beings aren’t involved, but 90% of the electrics problems I’ve run into are the result of butchery perpetrated by previous owners.

 

[latebird]

So are you saying don’t buy the Chinese electrics, or be aware of the differences and adjust accordingly? I’m sure your statistics are accurate when human beings aren’t involved, but 90% of the electrics problems I’ve run into are the result of butchery perpetrated by previous owners.

I'm not saying not to buy the Chinese electrics - it's Chinese electrics to begin with. It's just that what is blue on one end may be yellow on the other end - you have to have a road map (electrical schematic) to get to the destination.

And the butchery by previous owners comes back to faulty electrical connections whether they are not making good connection or connected to the wrong thing.

 

[DoneMantis]

The problem with the Chinese electrics is when Polaris mated their controls to the wiring harness, wires changed color at the controls and it becomes confusing.

On the Std Polaris, the black wire is the kill wire and the key switch performs basically two functions - when the switch is off, the black wire is connected to the brown wire to kill the spark - then the switch is turned on, the blk is disconnected from ground (brown is ground) and the battery pos (red) is connected to red/blk: one makes while one breaks and it is the opposite from one position to the other (newer and EFI models are completely different) whereas the Chinese key switch connects the battery (red) to brown (switched positive) AND connects the blk/wht and blk/blu.

The Chinese wired machine kills the spark then either the red-brn or blk/w -blk/blu connection fails (note: 6 wires to the key switch and only 4 used)

View attachment 145684

Blk/blu becomes blk/yel at the tether switch
View attachment 145688
Blk/yel is connected to black at the LH switch
View attachment 145690

Black is ground - lose the ground connection and the spark is killed
Blk/wht at the CDI unit is ground - disconnecting it will kill the spark

Remember: 905 of all ignition problems are connections and 90% of all connection problems are grounds

Thank you for all of the great information. I will begin checking grounds and connections as well as switches when I find the time.

 

[DoneMantis]

Update: It now has spark! I began checking grounds and connections about a month ago and everything I checked seemed fine so I decided to just buy a new aftermarket CDI box from eBay for 20 bucks and it completely fixed the no spark issue and runs great again! Thank you to everyone who replied.

 

[cliffno350]

Along these lines, I have a 2002 sportsman 90 and gone through wiring and checked everything and figured bad cdi, so put new CDI in and I get 1 spark then nothing, don't know what the connection on back of cdi is about?
Also the blue wire ?

 

[latebird]

You got a generic Chinese CDI unit - it won't work, Polaris has a proprietary wired CDI unit

 

[DoneMantis]

Along these lines, I have a 2002 sportsman 90 and gone through wiring and checked everything and figured bad cdi, so put new CDI in and I get 1 spark then nothing, don't know what the connection on back of cdi is about?
Also the blue wire ? View attachment 166755

That CDI unit looks identical to the one I purchased, which fixed my issue. Installation was slightly confusing because of the fact that the blue wire isn’t used at all and the brown wire needed to connect to the grey wire on the wiring harness. I also unscrewed the little plate on the bottom of the cdi, which I believe is some kind of rev limiter and likely has nothing to do with spark at low rpm’s.

 

[latebird]

You are right about the plate, it is a rev limiter - installed is about 10 mph slower than removed. Blue wire is unknown; it may boost top end or kill the engine if connected to the correct circuit, but I do not know what it is to connect to. The instructions that may or may not have been included with the unit would detail the function of the blue wire. As long as the unit restored spark it is considered a correct part by the distributor.

 

[cliffno350]

So a new cdi ?

 

[latebird]

So a new cdi ?

Let's see - you bought a new CDI and it did not fix the problem, but DoneMantis installed a CDI that looks identical and it solved the problem?

I would test the electrical system and replace the defective unit or repair the defective connection, but I run a shop and prefer to find the problem before replacing parts. Everyone else replaces parts until the problem is gone. I suggest you replace the stator (if it's an AC ignition) and see if that fixes it.

 

[cliffno350]

The stator tests good and the stators job is to charge the battery, the pick up not stator telles the CDI to fire the coil, I was getting no signal from CDI and no spark, new cdi And now I get one spark. Literally one spark and then nothing.
Been doing this stuff a while, this is a first.

 

[latebird]

This is the ignition system - does the stator have any thing to do besides charge the battery?

The pulse coil grn/yel to ground tells it when to fire - the charge coil blk/red to ground charges the CDI so it will discharge into the coil when the pulse coil tells it to - the black wire kills the spark when the key switch is turned off and disconnects the blk wire from ground. Notice anything? The battery is not part of the ignition circuit!

Maybe this will help.