I have a 2000 (yes 2000) edge 440 XCF.... engin #0000007 This sled was never raced (it was a racers edition only in 2000) Tho it was riddin like it was suposed to be. it had 3700 miles when sold. next guy tried this an that an blew up sled... i bought it for 900 .... got spec sheet from dealer an bought ALL PARTS OEM for it...(pistons rings slide needels main jets clutch spring an weights). my National Gaurd buddie that IS polaris certified rebuilt engin,( forgot to mention nikisil cyl too)... i ran ploaris gold oil..... i was able to enjoy 700 miles on that rebuild.... engin ran gr8 when cold after that.... but soon as it warmed up... it fell on its face till 6000 rpms..(but never went past 8000 rpms).... i installed two new polaris pistons an rings AGIN... got 300 miles out of it.... then back to being a dog..... now i was at our local pawn shop an found a 2002 . they told me it has the SAME problem. Our local polaris dealer says they were not a trail sled...TRUE.... bu tI race ATV's... this is my winter excersize... im NOT diddy bopin on this thing.... I Fell in love with this sled when it was new... an now that i have it . its a pain in my ARSE.... can anyone help me here?