A friend of mine has a â€˜97 Polaris XLT Special that falls flat on it’s face when held wide open. At 3/4 throttle it runs great; 70 mph at 7800rpm’s. But when you open it up all the way it dogs down to 6800rpm’s & 45mph! I know these sleds were boat anchors, but we’ve tried everything to figure out what’s up with this sled. Weâ€™ve been to the dealer for a timing check, changed carbs, unplugged the kill switch and ignition, removed air box, changed exhaust. The only upgrade from stock (that weâ€™re aware of) on this sled is electric start was added. HELP!
When you say â€œtiming checkâ€, at what RPM did you check? This problem could be caused by the CDI unit, Iâ€™d try swapping that out next. While this isnâ€™t something weâ€™ve seen on XLTs really, we did find this to fix a similar issue with some older 580 Cats.
Another thing you should verify is the crankshaft index, since many of the 95s and 96s spun cranks. If one of the cylinders is out of index, this would change the port timing and could make the sled act this way also.