96 foreman 400 no spark

[Bbrown 2]

First off I’m an auto tech with near 30 yrs experience I’m the guy people take electrical  stuff to that no one else can figure out.   I’m not a novice.   I also know that I don’t know everything.  that said, I have a 96 foreman that my neighbor asked me to fix.   No spark.   Initially tested the wires.   Ground on the light green and red wire in neutral. Neutral light comes on.  The black and white wire has battery voltage shuts on and off with the kill switch. the blue and yellow wire had no short to ground or power and had 350ohms (in spec) the green and white wire is good ground.  The yellow wire had no shorts to power or ground, and wasn’t open between the cdi box and the rectifier plug (unplugged).   The black and yellow coil wire was also good no shorts or open.    Ground on the coil was good.    I ordered a cdi box and plugged it in.    It burned a hole in it and the yellow wire got hot.   I replaced the rectifier assuming it was shorted internally and the cdi and coil for good measure.    Still no spark.  I replaced the pick up coil.  Still nothing    I did them all again and still no spark.   I’m starting to feel really stupid as I have a good 15 hrs on this thing and it’s not a complex system.   I have tested and retested and tested again the wires are all good   Is there something else in this system I am not aware of or doesn’t show up in the service diagnostics?   Thanks for your help.  

[Goober 1,555]

Did you use an OEM CDI?

 

also when you turn on ignition you should get a steady neutral light and the oil light should come on momentarily and then go out 

Edited November 8, 2021 by Goober

[Bbrown 2]

Thanks for the reply.   The neutral light is steady and oil light comes on.  I did not use oem.   I know in the auto motive world we have about 20% fail out of the box and oem isn’t much better but three in a row bad?   At this point it has to be something of the sort.   Is oem any better?   

Edited November 8, 2021 by Bbrown
Edited for clarity.

[Fishfiles 20,147]

Welcome to the forum --- OEM parts is the place to start 

[shadetree 5,977]

did you ohm out the stator ?, and yes, oem c.d.i. all the way..stay the heck away from china crap !.

[Bbrown 2]

Thanks.   I’m going to get an oem cdi coming.   Yes I checked  the stator.   All three yellow wires were the same (I don’t remember what that was) and in spec by the manual.  

can you manually fire those coils like an old points coil?   Running wires to the battery and bumping the ground on and off?   I couldn’t get a spark off my coils.  Some automotive won’t work that way are these the same?

[Melatv 797]

Hi: The coil needs a 100 + on the primary side-- I noticed that the wiring diagram (21-1) has the wrong color code on the N&R change switch -- refer to section 18-0 to change it to make it right.

 

[Goober 1,555]

Will the battery pass a load test? 
 

Run switch to RUN not OFF
 

also please note oil light should come on momentarily and then go out. 
 

How’s the plug look? Sooty? Check manual and ensure you get the correct plug

[Bbrown 2]

Thanks.   Yes I just bought the battery.  Yes the kill switch and ignition switch are both on.   I even jumped around it to make sure I didn’t have a false reading on my volt meter (enough voltage to read battery but enough corrosion to have no current).  It’s good.   The light comes on and off.   The neutral light stays on (in neutral    It’s the correct spark plug and I’ve put a couple different new ones in.   The only part of this system I haven’t replaced twice or more  is the flywheel.  And it has its pick up still on it and passes the the pick up coil close to to tdc.   The flywheel bump is steel not a magnet like on an abs sensor or something correct?       I’m waiting on an oem cdi box  but this thing has me

beyond frustrated as it’s a simple system but it won’t work.   

[Goober 1,555]

Sometimes you have to go backward to go forward; go back to the original configuration. Start from scratch other than the fresh battery and OEM CDI. You need More clues.
What was the Owner doing when it quit? Did it just sit forever? the battery died and wouldn’t start? Battery died and he continued to start it with kicker? It quit while owner was riding? He washed it? Any rodent damage?

 

Generation of spark starts with battery, pulse generator, CDi and coil. I would put all the OEM stuff back on. Get the battery fully charged while you’re waiting for the CDi. If you have to do something, Carefully inspect all wire harnesses. Clean the connectors with contact cleaner and apply a thin film of permatex dielectric grease. I use plumbers flux brushes.

 

i pull the spark plug cap off and inspect per manual; if the wire and spike has corrosion clean it off with a .22cal bore brush and snip off half inch or so of the plug wire

 

check fuses too

Edited November 13, 2021 by Goober

[Goober 1,555]

That old rectifier you replaced might be bad; be careful  about using it

[Bbrown 2]

Thanks for the suggestions.   I don’t remember what happened when it quit.   At the time he was tired of spending money on it And got a different 4 wheeler.   It sat for a couple years then one of his employees wanted it and I got roped into fixing it.  
I have started over at least three times before I posted anything.   The original  rectifier is bad as in makes the yellow wires hot bad     I have tried every combination of the other parts.   Nothing.   I have a good 25 hours on this.  I have followed every wire, every connection at least three times     the harness is all separated out there are no opens or shorts in the wiring.   The connections and splices are all good.  I have run my fingers down each wire looking for internal corrosion, none.    this thing should run. I’ve had two bad parts in a row before but i have three cdi boxes and nothing.  If this oem one doesn’t work I don’t know what else to do with it.   

[Goober 1,555]

Only other thing like you mentioned flywheel.

is woodruff key broken and it’s not spinning properly

 

well let’s see what oem CDI does first

Edited November 13, 2021 by Goober

[Bbrown 2]

I finally got an oem cdi box and I now have spark.    Now on to the fuel system.   Lol.   Thanks for the help.