I just purchased a 2000 426, it is all stock except for a bills header and muffler. I was riding down my street and I noticed that occasionally when I get on the gas in one of the tall gears it feels like the clutch will momentarily slip. It almost feels like I am on the gas and someone has squeezed the clutch for a mili-second. What do you think is causing this? Do you think I should replace the clutches? Is there something I have to adjust? Could it have something to do with my oil being dirty? I don't think it is in the transmission because it doesn't always happen and it doesn't make any clunking noise, plus I have had gear boxes go out in shifter karts and this is different. Thanks for any advice!