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Discussion Starter #1
OK here we go...

I have a 1999 Polaris XCR 440 that on snow and stand will not rev out past around 6500rpm. Full disclosure - I've had lots of Polaris sleds of all kinds and do all my own work. I'm pretty versed in small engines and this one is driving me nuts!!

The sled is all stock with the exception of a TempraFlo that the PO installed. I bought the sled with this issue that the PO could not figure out, he said he bought it that way also. It's a near mint sled with 2000 miles so it's worth saving from the dreaded part out.

Here is what I have done so far.
Compression test - 125lbs both cylinders
Drained tank and replaced with 91 non oxy
Verified all fuel lines are clear from tank pick up to carbs
Removed carbs, cleaned, verified all parts are stock and to stock settings. All stock jetting.
Inspected TempraFlo and according to the instructions it's installed correctly
Synced carbs and set idle
Inspected reeds, all good
Completely serviced VES system with new bellows, gaskets and guillotines completely clean and passages clear.
Installed new OEM belt and set deflection
Rebuilt fuel pump
Removed secondary and inspected - Perfect condition
Inspected Primary, removed spring, everything is free and clean
Inspected driveline - everything moves freely
New plugs, clipped off 1" of lead and reinstalled caps
Hooked up timing light and I have spark on both cylinders at all RPM range that the engine will go in.

This is my 2nd XCR 440 but first with VES and I've had all kinds of Polaris sleds from vintage to a couple years old but I'm hitting a wall with this one. It starts right up, idles perfect revs up to around 6500 like it should but then it's like a rev limiter kicking in.

All I can think of is the CDI is going bad. If it was the stator i'd most likely loose spark when it stumbles with the timing light hooked but up it still pulses when it starts to stumble. I did get both new OEM clutch springs (originals are over 20 years old, so preventive maintenance) to be installed but on the stand even with out of spec springs the engine shouldn't stumble at 6500.

I know these are really picky sleds and everything needs to be perfect for them to run right but i'm almost to the point of throwing parts at it (CDI). My next move is to go through all the wires and look for anything suspect or bad connections from the mag to the CDI. After that i'll get out the multimeter and see what values I have but on old sleds it seems they are not always a sure sign of issues.

Also my friend at the dealership said it sounds like the guillotines not opening but I explained that they are completely clean and rebuilt so he just said "well if you did all that then it's probably the CDI, they were problematic in the day"...

What am I missing? Who is the guru on these sleds? I know that the 98-99 is a little monster and need someone that knows them well!
 

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It sounds like you've gone through pretty much everything, the only things i can think of would be issues with the clutch, bad CDI, and track tension
 

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Discussion Starter #3
Yup, checked the track and the clutches are good. I went thought the wiring and everything looks good with good connections. I need to test the stator and CDI and see what values I get. If anyone has a spare CDI in central MN that would let me swap it in quick to test i'd jump on that lol!
 

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I'd do a cdi.. you have enough hours in it doing everything else.. and really, whats left to check?

Sent from my SM-G960W using Tapatalk
 

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All grounds clean? Did you ohm check the coil cold and hot to make sure it’s in spec? Is the spark bright blue? Ohm check the stator hot and cold as well.

Just a few free things to check before dishing out the coin for a new cdi.
 

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Discussion Starter #6
Looks like you cannot test the CDI. I'll check the stator and grounds next. Also I thought of checking piston wash and I'll get new plugs and do a plug chop. If they are fuel washed then I feel the spark or timing is off under WOT. I took it out last night and its loading up and leaving a smoke trail when I go wide open. While riding it just barley gets over 6000 and "bahblubburblebah" I had a Mercury 75hp that did the exact same thing and it ended up being the CDM's (coil packs).
 

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I would check base timing while your into the stator ( im not sure if the stator plate is adjustable on that engine).. your symptoms sound like bad timing, either caused by the stator, or cdi (spark advance)

Also, replace the plug caps if you haven't already. I drove my indy 500 efi for half a day thinking I had a bad injector, once the sun went down you could see the spark jumping from the cap to the head... I was also limited to about 6000rpm

Sent from my SM-G960W using Tapatalk
 

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Check your pipe to make sure that you don't have a rodent nest inside and also check carb vent lines to make sure their not plugged.
 

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Discussion Starter #9
Well I finally got a new timing light and on both leads the light cuts out at 6000 rpm. The light pulses normally until 6000 then it flickers and completely goes out until it revs down back from 6000. I'm waiting on a new multi meter to test the stator but I think its the CDI... Either way we have a ignition issue.
 

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Discussion Starter #10
Update -
The CDI is fine, I borrowed a CDI off a 98 700 RMK and same issues. So now I wait for a multi meter to test the stator... I hate old sleds LOL! BUT i'm getting close and rest assured I will follow up when its fixed.
 

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Discussion Starter #11
So I removed the stator, brought it inside to get it to the 68 degrees for testing. I followed the service manual and according to my multi meter it tests fine. So i'm officially at a loss... The pistons are fuel washed and when it gets to the magical 6000 its like a rev limiter kicks in.
 
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