Marc, $250 is cheap when you consider that you have to spend $2,600 to race the RMC if you have Leopard 😆
Zev, if I was going to race Bandimere, I’d buy a Leopard, and I’d buy it from JB. I think he knows the most about that motor locally, and from what I’ve seen, he provides his customers with great service. The leopard package is basically a small carb that is easy to tune and an electronic system that allows for high RPM’s. This results in higher maintance, more piston and reed changes for the motor. It should be easier to tune, and easier to drive as you’re not as penalized as much as the Rotax if you don’t keep your RPM’s up in the corners. Where you’re going to lose time to the Rotax is at the end of the straight. The larger Carb on the Rotax simply allows for higher speeds at the end of the straight. However, the small carb makes for an easier to drive package.
If I was racing IMI, or CRE, I’d go with the Rotax. I think it’s the motor that’s in the front most of the time on those tracks, and I’ve found the guys that race that motor very helpfull. As you know the Rotax come sealed, and with that seal you’ll spend less time in tech. The carb is what’s called a variable venturi carb. The result of that is that you’ll need to learn to roll on and roll off the throttle. Quick stabs on and off the carb will load up the motor and bog you out. It’s not easy to learn, but hey I’m almost there and I’m no brain surgeon. However, our local brain surgeon was still trying to figure it out that last time I raced with him :D. Over time I’ve learned to roll on the gas as I feel the motor pull.
The jets take a few minutes to change, you usually need to change them during the race day, most guys are using the MaxJet software with a weather station to gauge jet choice. It’s an extra expense you should take into account. The other aspect of this motor is the power valve. It should result in faster acceleration than without it. It’s not on the Leopard. With the Rotax, you really need to stay within the 6000 – 11,000 power band, and within that, the 8,000 and above is where you really need to stay. If we had an adjustable clutch, you can adjust that, but we don’t, they lock up down around 4,000 rpm. What this means, is if you slow down in a tight corner, you’re going to get killed coming out of it. The Leopard has a higher stall speed, it’s therefore more forgiving. So if you can stay higher in the RPM band with higher cornering speeds, the Rotax is faster than the Leopard. But if you have tight corners like at Bandimere, the Leopard will have the advantage.
However, if the CSC insists on giving the Sonic motor a big advantage by not adopting SKUSA weights for that motor, that would be the way to go. Also, by far the best HP for weight in the masters class is the Italsys with Electronic ignition. Who know why, buy that motor has at least 1.5 more peak HP, but no additional weight than the Leopard. I don’t know of any local support though, and if you’re new, local support should be your biggest deciding factor.
I’m going to take a quick tangent here, the biggest thing I’ve learned is you’re going to be far better off buying a motor where you can get the best support. These little motors aren’t easy to keep runing, and you can save year’s of frustration if you buy your motor from someone that has good support. Of course, sometimes even when you do that, the shop can go out of business. 😥