There is a difference between the old style and new style clutch. The new style is much better at standing starts. No question. But when I ran the old style clutch I was never left in the dust as Jeff say’s. But I knew of ways to make it get off the line better.
My engine is an 05 or so with the only updates being the Airbox and clutch and I’m able to run up front in CES. But I have noticed some guys got FAST the last year or so by going with a new package.
Just get the new style clutch and airbox and you should be fine. Getting a bad start really hurts in road racing. I’ve had a few of them this year and losing the lead draft right off the bat really hurts. The Rotax is finicky. If you don’t have everything just right your going to be a little slower. I only race about 3 times a summer and if I don’t have everything just right I’ll be about a second off. The more you race the easier it is to get things just right.