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An official CFI Engine Failure Thread

G
Dec 2, 2009
38
2
8
failure mileage

A lot of horror stories about dragonsbut you know what I see in this thread is a lot of failures in the 1300 - 1600 mile range. Although not good, you will also see that a lot of pro's are now starting to fail in this same mileage area.

So are the cfi-4's as bad or??
 
M

maddog21

Well-known member
Mar 19, 2008
2,662
243
63
38
Charter Oak, Iowa
not my sled.. from someone I know
2009 dragon, broke down at maybe 2000 miles? full stock. engine failure: piston or broke rod?
2013012895183803_zps99260e8c.jpg
 
I
Dec 25, 2007
28
4
3
40
Minnesota
Clutch side piston and skirt
Date of Failure 1-5-13
Year 2007
Make Polaris
Model Dragon
Mileage 2300
Engine Displacement 700
Track Length 155
Brand of fuel and octane Exxon 91
Oil Used VES Gold
Ethanol Resistor connected
Elevation 8,000 (top of the world montana)


Modifications, slp pipe set
Fuel Controller's no
Intake Modifications no
Clutch Mod's none (62g weights)


Type of Sled Transportation open trailer but always covered
Sled Storage trailer covered or heated garage: Heated garage and towed in encolsed trailer all the time
Weather Conditions, Air Temp on the date of failure 25 degrees, clam winds, and sunny... Sled was running about 125 for engine temp and had been all day. had about 50 miles on for the day and were about to make the 20+ mile runback to Cooke City... Sled had been shut off for five or ten minutes, started it back up made it not even 1/2 miles at half throttle and clutch side cylinder skirt broke off along with a good portion of the piston. Of course all parts fell in to the crakcase :mad:
 
B

BC_mtn_rider

Well-known member
Nov 11, 2012
160
66
28
48
Surrey B.C.
My 10 Dragon is dead

Last week up in whistler climbing a small hill in a few ft of fresh and she just died like I hit the kill switch. Only 1060 miles on it and the number 2 piston blew, scoring the cylinder wall as well. My warrantee exp in Dec 12. Looks like I'm hooped. I guess ill try the Mountain tek kit and get a refurbished cylinder.
I was planning on snow checking a 14 pro but not even sure if I trust a Polaris engine as I continue to read about the on going piston troubles. Any tips on my top end rebuild would be appreciated as this will be my first!
 

Hawkster

Well-known member
Lifetime Membership
Apr 22, 2010
7,960
6,232
113
AK
She's a bute .
 

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S
Jan 28, 2008
245
9
18
52
Denver, CO
Date of Failure - March 2013
Year - 2008
Make - Polaris
Model - 700 Dragon
Mileage - 2500 miles
Engine Displacement - 700
Track Length - 155
Brand of fuel and octane - 91 with up to 10 % ethanol
Oil Used - VES Gold
Mapping - stock
Elevation that you ride - 8000'-13000'
Area's or locations that you ride - All over Colorado

Modifications - None, totally stock.

I bought the thing used in Dec 2011, so I don't know it's whole history.

A crank bearing disintegrated and basically destoryed the whole motor.

My 2001 mountain max has 10,000 miles plus and is still running like a champ. Why, oh why doesn't Yamaha still make 2 strokes???? Or someone make a kit to install a Yammie triple into an IQ chassis????
 
E
Feb 13, 2014
1
0
1
just re built my 09 polaris assault. cracked cylinder and welded ring to piston. installed fix kit but thinking its time to sell. should i put oil in my gas to break it in?
 
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