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Long time user, minimal poster but I’m out of my league with this issue. I tried searching the forum for this issue but was unable to find anything helpful. I recently picked up a 77 Motoski futura 400 (twin to an Everest I’ve found?) in awesome shape and I’m trying to bring it back to life. At some point Someone has replaced the original 400 with a 440f/c. Dumped all the old fuel, cleaned the carb, replaced all the fuel lines and primer, new plugs, wires and caps. Filled with new fuel gave it two pulls and she fired right up and ran great. Turned it off to replace the sticky throttle cable and then fired it back up. Ran great....for about 10min.....then just died like someone hit the kill switch. Found No spark on both sides, noticed one of the kill switch wires was not in the greatest shape and the red wire from the voltage regulator broke off so I Unplugged the switch/light harness and checked for spark again and still nothing. So now I’m stuck scratching my head looking at this polarfire CDI I know nothing about. How do I begin to test this thing? This is the 017 polarfire. All the wiring going to the cdi is in good shape. This is new one for me and any help would greatly appreciated. Thanks.
 

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You say "unplugged the switch/light harness", you did this at the plug on the fan shroud by the recoil/start rope ?? if so - good.

Was or is this sled a electric start body ?? As OEM the wire to the voltage regulator is a yellow wire, maybe it has a aftermarket regulator and may have a red wire ??

If it was a E start there is a red wire to one pin on the rectifier. The reason I am on this is cause as OEM non e start the only red wire you should have is from the magneto to the Polar Fire box. The red wire charges the box and should have nothing to doo with lights.

I would unplug the wire from bottom of CD box and ensure all connection in there are good. Rd charges the box (from ignition generating coil) one Wh/Rd and one Wh/Rd/Bk they are grounded likely at the box mount screw, a Wh/Rd and Wh these come from the trigger coils into box and fire each side, then a Br goes from box to ground pin in main sled harness, ensure all grounds are good.

PS, you have a ignition system from a 75 Everest.
 

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We had similar issues with a 75 440 Everest but only on one cylinder. It was temperature related. Ran fine until it warmed up then lost spark in one cylinder. Checked the trigger coils resistance and wiring, all looked good. Tried icing the box and the spark returned so it was something in the box that would go bad when it warmed up.

Ended up replacing the Polarfire CDI with a new reproduction Fireplug CDI that I purchased from Scott at Hewtech Electronics (see contact info below).

Runs great now.

Scott Hewelt
Phone: 810-765-0820
email: [email protected]
website: www.hewtechelectronics.com
website: www.cdibox.com

Sent from my iPhone using Tapatalk
 

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Discussion Starter · #4 ·
396F/A, correct, unplugged the harness at the fan shroud. I'm not sure if this was an e start model, I would assume that it is because the key switch has what I would think is a "momentary" crank position when turned all the way clockwise, however there is no starter motor or battery. What I called the regulator is likely a rectifier as it has red, green and yellow wires going to it, also two ground wires attached To the mounting bolts, one blk/ylw and one blk (maybe this is an issue?). The connections and wires on the harness that plugs into the polar fire are in good shape and make good contact. There is a wht/red and a wht/red/blk wire that are attached to the CDI by the mounting bolts. One coil mounted to the box looks to have been replaced before as it's been spliced. Are the trigger coils the ones mounted on the box? If so, can they be tested? Thanks for your reply.

Harrison, still no spark today after letting sit overnight. I also thought that maybe an issue. I did see the hewtech boxes but looks like they are out of stock right now. I'm hoping to confirm the issue before I buy one of those. Thanks for your reply.
 

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The coils on the box are not trigger coils, they are high tension coils. I am not aware of a test for them.

The trigger coil or Ski Doo calls em pick up coil are in the magneto assebly, there is two, one for each cylinder. Then one exciter prong on the hub that excites either trigger at 180 degree. This system is not a wasted spark system, it only fires once per side.

Get the ohm meter out. I know these tests some times lie, but you may learn some thing.

Unplug the wire/plug from bottom of CD box. connect meter to red wire from magneto and to ground on engine, you should see 325 to 370, this is testing the ignition generating coil.

Then check the Wh to ground and Wh/rd to ground, this s testing the trigger coils, you should see 55 - 60

I am sure you have a sled that was a e start. Any wires to the rectifier etc will have no affect on the ignition as there is two totally independent systems. Unless some wiring has been messed with.
 

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Discussion Starter · #6 ·
Thanks 396, I’ve got my multimeter at the shop I work I work at. I’ll run out there, grab it, test and report back.
 

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White and White/Red wires are from the Trigger Coils.
OOOPPPS, sorry about my mix up, eyes, fingers and brain were not on the same wave :p
 

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Discussion Starter · #9 ·
Red ignition generating coil measures 315, trigger coils measure no reading (OL). These were all measure from the harness plug at the recoil housing.
 

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NO, you have to pull the plug off the bottom of the PolarFire box and prob the wires in that plug
 

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Discussion Starter · #11 ·
396 my brain and fingers were not working together, I DID test from the CDI plug. This tells me the trigger coils have an open in them somewhere. Seems strange they would both be no good? It’s still odd to me that this thing was running very well then just nothing. I guess the next step is to remove the recoil so I can inspect the magneto?
 

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Discussion Starter · #12 ·
Is the brown wire grounded through the magneto or is it grounded when plugged back into the main harness?
 

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I think it grounds in the plug but the end of the brown wire is bolted to the case.

Did you test between the trigger coils and the engine case or the brown wire? Also test the end of the brown wire to engine case for continuity.
 

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The brown goes from the box to the chassis harness - to ground
 

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Turbopete, I tested the trigger coil wires at the plug and used case as ground. I tested continuity from the brown wire to the case and had no reading which I though was strange, hence the question as to where it grounds. I’ll re test when it’s plugged in. Could having a bad ground fry the trigger coils? This may be a silly question, do I need to test resistance in the trigger coils as I pull the recoil? It still seems odd to me that both trigger coils show no reading. Am I missing something?
 

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http://www.vintagesnow.com/Ski-Doo_files/75_eve440ewiring.jpg

As you can see, the brown wire supplies ground for the ignition box. You should have continuity to case ground from the brown wire at the plug for the Polarfire. If that brown wire isn't grounded or broken, it may be your problem.

No, the resistance test is a static test and you don't have to be cranking the engine.

Trigger coils to ground should give you the specified reading, if not they may be open( unlikely) or a wire broken or the wires to the triggers that are supposed to be grounded are not! (Can you see the wh/blk and wh/red/blk wires where they come out from stator - follow them and see if they are attached to ground) Study the diagram and try to understand it, it will help you in your testing.
 

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Discussion Starter · #17 ·
Ok So admittedly I overlooked the wh/bk and wh/rd/blk wires being grounded to the body of the CDI and I now have continuity on the brown wire. They were on there before but I disconnected them while I was messing around. White trigger coil measures 53.5ohm, white/red trigger coil measures 53.4ohm and the charge coil measures 315 ohms.

At this point I'm sure it's either the CDI itself or the coils, and I find it very unlikely that both coils failed at the same time, so I'm leaning toward the CDI. Is there any tests to be done on the coils? I did find that the PTO side coil was not tightened to the side of the CDI box but after snugging that down still no change. I'll see if I can scrounge up a CDI from a local sled wrecker.
 

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Discussion Starter · #18 ·
Also, is there any harm in leaving the rectifier in place of a voltage regulator? I don’t plan I putting e-start on this sled.
 

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Discussion Starter · #19 ·
And a though that crossed my mind.... I have another complete 77 Everest here in really rough shape, needs crank seals but other wise runs. It has points ignition on it that I could swap over although I’ve heard it’s quite involved.
 

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Your easiest option is to just find another Polarfire or order one from Scott at Hewtech. He was having problems developing one for the later sleds ( figured out now), but for yours it should not be a problem. Fully guaranteed, so if you plan to keep the sled, a good option.
 
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