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Discussion Starter · #1 ·
Good morning everyone ....I am new to doo talk but have always been a Skidoo guy.

I have a 2014 Ace 900 I purchase for my GF and it idles rough and has no power ...nothing smooth about it !!!

I called a friend that works for a Skidoo dealer and he said to look in the spark plug wells for water....there is none ....the sled has 700 miles on it and has always run NON ethanol fuel .

There are no marks on the coils as there would be if they were shorting out and the plugs look perfect.

Any help would be appreciated.

Thank you
 

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Anything blocking the air flow?

Did you put fresh gas in it?
 

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The 900 ACE is generally rock solid but there have been a few minor issues reported. I have three of the them and they are great sleds!

There have been some people who have experienced issues with the ignition coils. If you have a bad one, it could be causing your issue. They are not very expensive and easy to replace. I carry a spare in case we have any issues on the trails but I have never had to use it.

You may want to pull the hood and check all of the connectors leading to the coils as well as all of the wiring harness connectors and also check the plug wires.

I'd also pull the connectors to the coils and check the pins. I have heard of pins not being seated in the connector body and push back so they don't make full contact. You should also check for any broken or bent pins.

Are you getting any warning lights on the cluster?
 

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Discussion Starter · #4 ·
Fresh fuel yes

Air blockage I do not see anything

I have seen that SPI makes a coil for these already and have to say that if they are making them there is an issue

I will check all the pins and connections to verify all is good

No warning light but the Tach jumps up and down 300 rpm at idle....there is an obvious fuel or ignition problem
 

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If the ignition coils check-out ok, then it could be a fuel pressure problem.

I would check the pressure out of the fuel pump after eliminating the ignition.
 

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I couldn't find a test procedure in the Service Manual but according to the specs in the manual:

Ignition Coil - Primary should be 0.80 to 0.97 Ohms

Ignition Coil - Secondary should be 9.5 to 13.5 Ohms
 

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Discussion Starter · #9 ·
Befor you go too far I am going to put a set of plugs in it and see what happens....There are 3 connectors on each coil and there is no wire going to the center one so I checked resistance on all 3 coils on the 2 outside contacts an they are all the same ...I have plugs here for it ....I will see what happens and let you know ASAP

TY
 

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The manual does say that fouled plugs will result in rough idle and loss of power so that is an easy step. You typically don't think of plug issues with the 4-strokes but depends on how many miles, whether any oil is blowing by the rings, etc.

You may want to check compression while you have the plugs out just to get a baseline of where you are.

Besides the resistance specs I posted above.... some guys have reported coil issues without it causing a CEL.
 

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Discussion Starter · #11 ·
*****Resolution*****

Thank you for the resistance ...Values where right within specs.

I am the kind of person that will only replace parts when I can verify the failure and although this is not always possible I do my best.

Tested the resistance of all plugs and fired them all nice blue spark but replace the plugs....No more issue I do know that short run time can damaged even the best plugs.

Thank you for the technical info ....I am al set for now.

If I can help anyone I am a Nitro and Blizzard trailer dealer Just give me a shout out I am in Western MA. but also have a place in Upstate NY in the Adirondacks.
 

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Glad you took care of it. I didn't see this until now.

But for future reference, and for others...you described a classic fouled plug on these machines. Anytime there is suspicion of one of these engines running on 2 cylinders (typical symptoms are rough idle and low power)...an IR gun pointed at the exhaust manifold will tell you instantaneously if your suspicion is correct, along with telling you exactly which cylinder is not firing. Just point the gun at manifold at each cylinder and compare the 3 temps to each other. The 2 hot cylinders are working as designed, and the cold one is the one with the problem. If the engine is relatively cold, even spitting on your finger and touching the 3 locations can tell you the same thing...or put a little snowball at each location. Sizzle, wet dot, sizzle means center cylinder is dead. Wet dot, sizzle, sizzle means left cylinder is dead. Etc. This water test won't work with a hot engine/fully heat soaked manifold cuz everything will sizzle. But IR gun will work even when hot...it can read the differences.

This 5 second diagnostic will send you directly to the affected cylinder to find the problem (almost always a fouled plug, or a bad coil), and you don't waste time messing around with anything else....such as needlessly changing 3 plugs and testing 3 coils, when you only need to check one, for example.

Good time to also tell people...Fouled plugs are VERY common on these sleds...if "short-started". So don't start these engines if you don't intend to actually take them for a ride...or at least let them run at idle for a solid 10 minutes or more, to get the circulating coolant fully hot....feel heat in the heat exchanger before shutting it down...if it's not warm under the tunnel, do NOT shut the engine off yet. Short starts on these engines cause fouled plugs very very easily. And the only fix is to swap the plug, which is not exactly an instantaneous project, if you even have an extra plug cuz most do not.
 

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*****Resolution*****

Thank you for the resistance ...Values where right within specs.

I am the kind of person that will only replace parts when I can verify the failure and although this is not always possible I do my best.

Tested the resistance of all plugs and fired them all nice blue spark but replace the plugs....No more issue I do know that short run time can damaged even the best plugs.

Thank you for the technical info ....I am al set for now.

If I can help anyone I am a Nitro and Blizzard trailer dealer Just give me a shout out I am in Western MA. but also have a place in Upstate NY in the Adirondacks.
Excellent! That is great news!

The one thing I like about this site is everyone is always very helpful when issues like this pop up...... and eventually they happen to all of us and we get stumped. Another set if "eyes" on the problem and past experience can be very helpful!
 

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VERY helpful thread. Wife's new sled had the same issue. I was not thinking fowled plug on a 4 stroke. I bet we short started it too many times. This saved me a trip to the dealer. Thanks
 

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Glad you took care of it. I didn't see this until now.

But for future reference, and for others...you described a classic fouled plug on these machines. Anytime there is suspicion of one of these engines running on 2 cylinders (typical symptoms are rough idle and low power)...an IR gun pointed at the exhaust manifold will tell you instantaneously if your suspicion is correct, along with telling you exactly which cylinder is not firing. Just point the gun at manifold at each cylinder and compare the 3 temps to each other. The 2 hot cylinders are working as designed, and the cold one is the one with the problem. If the engine is relatively cold, even spitting on your finger and touching the 3 locations can tell you the same thing...or put a little snowball at each location. Sizzle, wet dot, sizzle means center cylinder is dead. Wet dot, sizzle, sizzle means left cylinder is dead. Etc. This water test won't work with a hot engine/fully heat soaked manifold cuz everything will sizzle. But IR gun will work even when hot...it can read the differences.

This 5 second diagnostic will send you directly to the affected cylinder to find the problem (almost always a fouled plug, or a bad coil), and you don't waste time messing around with anything else....such as needlessly changing 3 plugs and testing 3 coils, when you only need to check one, for example.

Good time to also tell people...Fouled plugs are VERY common on these sleds...if "short-started". So don't start these engines if you don't intend to actually take them for a ride...or at least let them run at idle for a solid 10 minutes or more, to get the circulating coolant fully hot....feel heat in the heat exchanger before shutting it down...if it's not warm under the tunnel, do NOT shut the engine off yet. Short starts on these engines cause fouled plugs very very easily. And the only fix is to swap the plug, which is not exactly an instantaneous project, if you even have an extra plug cuz most do not.
Thanks for those tips. Never thought of the IR gun. I should've as I've seen engine tuners using it checking header temps on cars.
 
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