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1997 Skidoo MXZ 440F
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Discussion Starter · #1 ·
I have this '97 skidoo mxz 440 fan cooled sled, it had a broken pull starter we rebuilt it and that was done. It runs like crap at first. After a little bit we mess with the wires we get it to fire on both cylinders. Boom the thing was fantastic! So fast and peppy it just wanted to go. Ran good for my dad for a night we came back the next day it was running crappy again. We replaced the wires that didn't help with our issue and we replaced the coil pack next. that made the spark a lot better but it is still weird spark ( I can't describe it very well I haven't seen it I'm always pulling over the engine) my dad describes it as a little bit erratic but it has good spark. Before we replaced anything me and my friend were going to go riding, and It ran okay and me and my friend just said screw it and rode it while it wasn't running the best ( was firing the second one every now and then as I'd get some times really good power and other times not) then it just died on me a few days later as I was riding it with only one cylinder. and it would not fire that one cylinder at all anymore. And yes we have changed the plugs (we've bought so many plugs for it.) we've drained the tank cleaned the tank filter even though it wasn't dirty just because it sat for a while and refilled it with new gas and ethanol booster. . But that one cylinder fouls spark plugs left n right and both sides have good spark with multiple different spark plugs. Someone please help! Got some decent bit of money into it and i just want to ride it next season!! sorry if the story seems a bit choppy it's been a while since we've been messing with this thing. any questions or ideas or anything are appreciated
 

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Welcome
Did you clean the carbs and pay attention to the Pilot jet (up the tube) and air screw
 

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1997 Skidoo MXZ 440F
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Discussion Starter · #3 ·
Welcome
Did you clean the carbs and pay attention to the Pilot jet (up the tube) and air screw
We have not cleaned the carbs yet. I think my dad is etiher scared to do it or just really doesnt want to because thats what i keep telling him. What im going to do next is ive seen people say stuff about how the choke can be stuck or the needle n seat can go bad or something? Not really sure. I do believe we will have to clean the carbs eventually. Maybe if i put seafoam thru the engine and we try and make that one cylinder fire it will clean out the carb? not sure if we can get it going tho rn. Ill let you know what happens I might be going there today.
 

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The best thing go through this, it is guna be harder to get carbs out than to clean them!
Get a heat gun, the rubber is more flexable when warm (November is too)
Get a cookie sheet and make a pilot jet screw driver (std 1/4 blade with edges ground down to fit up the tube)
 

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1997 Skidoo MXZ 440F
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Discussion Starter · #5 ·
The best thing go through this, it is guna be harder to get carbs out than to clean them!
Get a heat gun, the rubber is more flexable when warm (November is too)
Get a cookie sheet and make a pilot jet screw driver (std 1/4 blade with edges ground down to fit up the tube)
I think my father doesnt want us to mess up the tune and have it just never run right again or something. idk why we cant. Ive been wanting to do it since day 1.
is there any way you can tell me what i can say to my father to ake him want to do it lol
thanks
 

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It really isn't as hard as people make it out to be. When taking out the air screws to clean them, tighten them down first to a light seat and count the number of turns it took to get them there.

Leave the idle screws alone, really nothing to clean there anyway unless the screw itself is corroded.

Everything else is just clean and put back.


Weird spark can be sensor related. The pickup for the spark trigger. Usually on top of the mag, little cover and the sensor is below it. If the clearance in out of wack, it can cause spark issues.
 

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Discussion Starter · #7 ·
It really isn't as hard as people make it out to be. When taking out the air screws to clean them, tighten them down first to a light seat and count the number of turns it took to get them there.

Leave the idle screws alone, really nothing to clean there anyway unless the screw itself is corroded.

Everything else is just clean and put back.


Weird spark can be sensor related. The pickup for the spark trigger. Usually on top of the mag, little cover and the sensor is below it. If the clearance in out of wack, it can cause spark issues.
okay thank you. should I look up a manual or shop guide of how to tune the carbs like how many turns they are supposed to be ? or just let them be the way they are and clean out the carb? and put it back the same
 

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okay thank you. should I look up a manual or shop guide of how to tune the carbs like how many turns they are supposed to be ? or just let them be the way they are and clean out the carb? and put it back the same
You can always count your turns on the idle and air screw. And for me it’s harder getting the carbs out than cleaning them. Also it’s not a bad thing to figure out how to do basic tuning on your sled. I would definitely take them out and clean everythin. There is a couple videos on youtube on tuning. DIGIT 9 has a good couple videos on it. And I would definitely check your manual as well to see what their factory setting is. Good luck
 

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Discussion Starter · #9 ·
Thank you! eventually I will post a good pic of the sled in here or on another forum. Might posts pics of me taking out the carbs as well not sure, might be fun lol.
 

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KC alot of those links are dead now especially the ones from ripperd.com or w/e they are. I did a write up on how to do mikuni round carburetors on few posts that breaks it down line by line if you want to look for it.
 

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Discussion Starter · #11 ·
KC alot of those links are dead now especially the ones from ripperd.com or w/e they are. I did a write up on how to do mikuni round carburetors on few posts that breaks it down line by line if you want to look for it.
is there a way you can send me this?
thanks
 

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There really is No tune in the carbs that you would need to change.
If your dad doesn't want you to touch it tell him the Stealer would charge him maybe $200 or more just to clean carbs LOL
 
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