1996 xp- no spark

[Jparadise81]

Hey guys, I need some help. When I got this ski the electrical system was torn apart and ive put it back together as best as possible. I replaced the mpem and redid all the fuel system but when I go to start it I'm fairly certain I'm not getting any spark because it's not starting. It's got new plugs gapped to .25 inches and I clipped both sides of the plug wires roughly 1/4 inch each. Checked all fuses and still no spark.

What else do I need to check?

Thanks guys

 

[Dennis]

In order to diagnose the issue you are going to have to know for sure whether or not you have spark.

Make sure the small ground wire coming from the rear electrical box is connected to the neg battery post. It will cause lack of spark if it is not connected. :cheers:

 

[Billy McLain]

Make sure you don't have any fuel leaking or a hull full of fuel vapors first.
Then pull one of your spark plugs out and put the boot back on it.
Hold the plug by the boot and touch the threaded end to the edge of the open cylinder hole and watch the electrode for tiny blue sparks as you turn it over with the starter.
This is best done when it's j u s t light enough to see OK. Sparks are very hard to see in bright light.

 

[Minnetonka4me]

with Getem burning a bunch of skin off I HIGHLY recommend buying a spark checker...they are like $5 at harbor freight.

If no spark, open the ebox and disconnect the black w/ red tracer wire coming off the MPEM. Check again. If you have spark then its the MPEM. If not, hook that wire back up and unhook the white wire off the coil. Get out your test light hook the clip to ground on battery, and put the pick on the white wire connector. Crank it over and the light should flicker. If it does, the coil is bad. If it doesnt, its the Stator.

The above is ONLY for 580-720s w/ 4 wire stators.

 

[Billy McLain]

with Getem burning a bunch of skin off I HIGHLY recommend buying a spark checker...they are like $5 at harbor freight.

Just read about that!
:agree:

 

[Jparadise81]

​

Thanks for the tips everyone. I light tested the white wire going to the coil before I left for the lake this morning and it isn't getting power while I'm cranking it over. Does that mean the pickup coil? The mpem was just replaced from a unit from 99spxxx so that should be good, or should I still do the test on the bk/rd wire off the mpem? I'm going to recheck all connections again just to be sure, but is there a way to check the pickup coil or stator? I just picked up a multimeter from hd today. Or is there even a stator in my 787?

And I read that same thread about the guy getting a face full of fire while checking for spark. Thanks for the reminder.

 

[Minnetonka4me]

Its possible its the box...but more likely that the pickup inside the mag housing has broke off.

Did it run with the new mpem ever?

There is no blk/red wire to pull on a 787....only 720-580 that have 4 wire stators.

 

[Jparadise81]

Its possible its the box...but more likely that the pickup inside the mag housing has broke off.

Did it run with the new mpem ever?

There is no blk/red wire to pull on a 787....only 720-580 that have 4 wire stators.

No it hasn't run with the new mpem but ive done the diagnostic and it checks out good. I figured out there isn't a blk/red wire when I went through and rechecked all my connections. They are all good but still no spark.

What's the best way to test the trigger coil without taking the mag cover off? And if that's the problem is there a thread on repairing it?

 

[Minnetonka4me]

You will need to open the front ebox and find the trigger wires...then ohm those two while turning the motor over. You should see a flicker. OR...take the front of the mag housing off.

Was this the same problem you were having before you bought the MPEM? Did you just buy the MPEM? No spark is typically the CDI box if it isnt the pickup.

The pickup bracket in the 96s were weak and known to crack off.

 

[Jparadise81]

You will need to open the front ebox and find the trigger wires...then ohm those two while turning the motor over. You should see a flicker. OR...take the front of the mag housing off.

Was this the same problem you were having before you bought the MPEM? Did you just buy the MPEM? No spark is typically the CDI box if it isnt the pickup.


The pickup bracket in the 96s were weak and known to crack off.

When I got the ski the mpem was already taken out, but I saw it and there was a hole melted on the back of it so I'm pretty sure it was toast. When you say check the two trigger wires do you mean check them separately with a ground or together? I'm new to electrical testing with a meter so any elaboration is appreciated.

 

[Minnetonka4me]

youll have to look at the wiring schematics to find the two wires; if you ohm it it should flutter when the magnet goes past it. If its broke off you shouldnt get any flutter in the numbers.

 

[Jparadise81]

I just had a thought, I converted to premix when I got the ski, so theres barely any oil in the reservoir. does the oil sensor kill the spark when it senses no oil in the reservoir?

 

[Matt Braley]

No it just turns the red light on that's inside the gauge.

 

[Jparadise81]

No it just turns the red light on that's inside the gauge.

Thats what I figured, but was reaching for something

Anyways good news, I tested the trigger coil and im getting power to the CDI so I decided to check the white wire from the CDI to the coil and what do you know, I have power there too! I checked the connections and im getting power all the way to the ignition coil. When I tested the white wire at the ignition coil last week I didnt have it plugged in to the coil (im new with electrical) so I wasnt getting a reading. Last night I tested it at the coil with the white wire plugged in and im getting power to the coil.

I checked the ohms on the primary winding and it read good at .05 or something similar which was in line with the manual. When I checked the ohms on the secondary windings (with plug caps removed) the meter didnt move and stayed in the "infinite" position. I checked the same way on my other ski and I got a reading of 15k ohms, which is in line with what the manual says which is like 13-19k. So sounds like the coil is bad.

My question is, the manual says that if theres a short in the secondary windings it will read 0 ohms, but on my meter (non-digital) 0 ohms is on the right side and the needle rests on the left side, so the needle techincally should have jumped from the infinite position (left) to 0 position (right)? Or if there's a break in the coil, would it just not move? Is there any other test I can do short of removing the coil from the other ski and installing it in the xp?

Just trying to confirm before I order a new part. Thanks for any insight

 

[Strizzo]

sounds like you have an open circuit on that winding. can you swap the coil from the other ski to see if it fixes the issue, are they the same coil?

Thats what I figured, but was reaching for something

Anyways good news, I tested the trigger coil and im getting power to the CDI so I decided to check the white wire from the CDI to the coil and what do you know, I have power there too! I checked the connections and im getting power all the way to the ignition coil. When I tested the white wire at the ignition coil last week I didnt have it plugged in to the coil (im new with electrical) so I wasnt getting a reading. Last night I tested it at the coil with the white wire plugged in and im getting power to the coil.

I checked the ohms on the primary winding and it read good at .05 or something similar which was in line with the manual. When I checked the ohms on the secondary windings (with plug caps removed) the meter didnt move and stayed in the "infinite" position. I checked the same way on my other ski and I got a reading of 15k ohms, which is in line with what the manual says which is like 13-19k. So sounds like the coil is bad.

My question is, the manual says that if theres a short in the secondary windings it will read 0 ohms, but on my meter (non-digital) 0 ohms is on the right side and the needle rests on the left side, so the needle techincally should have jumped from the infinite position (left) to 0 position (right)? Or if there's a break in the coil, would it just not move? Is there any other test I can do short of removing the coil from the other ski and installing it in the xp?

Just trying to confirm before I order a new part. Thanks for any insight

 

[Jparadise81]

sounds like you have an open circuit on that winding. can you swap the coil from the other ski to see if it fixes the issue, are they the same coil?

Unfortunately no, they are two different coils. I think I'll just order one from 99spxxx and hope it fixes the problem. I'll post up the results.