I have a friend that owned a 95 EXT580 that the seals were bad in it. This sled would start real hard (12-50 pulls) but after it was going it ran great. It was just a matter of time and the leak got too large and the thing blew. We found the seal problem during the rebuild process. Things that make you go hummm..
As far as the Cat bashing goes my cats have pulled them all home when they break. But when mine breaks my wrecker service will always be a Cat, no other brand will take my cat to the barn. Remember they all break sometime, its a matter of how much does it cost to get it going again!
the hard starting is definatley one sign but performance all around is affected. what do your plugs look like? they should be penut butter brown, a leaking seal will create a lean mixture leading to excessive heat, the plugs will be white. if your plugs are black and wet then it might be the cdi I personally haven't had one go just partly bad they either run or don't. you can check the seals your self by starting the sled and spraying a light bit of starting fluid behind the clutch and around the intake boots and onto any other areas that are accessable where the engine is split. have you checked the jetting or impulse line? fuel is good I assume you drained the tank and tried new gas. the seals are an unlikely failure on a newer sled but any part can fail, there is also a center seal that isolates right crankcase from left. the best and most accurate test is the leak down test if your dealer or mechanic is capable and willing if not you can make the neccsarry gear from a couple of plumbing plugs a gauge and a bycycle pump and check it yourself for under 20 bones.
e-mail me for a more detailed explanation on this if your dealer is a hoser and won't do it for ya.
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