I have a new Mini Swift (2 race weekends old) that runs fine once it’s up to speed but will not take off! I literally need to push it to help go and get out of the hot grid and on the starts it’ll falls to dead last while EVERYONE passes. Once up to speed (200-400 yards) it’ll be fine. I’ve changed plugs, tested other carbs, rebuilt the carb, replaced the needle and seat, adjust pop off, replaced the coil, fuel line, pulse line, you name it we’ve done it. We have a lot of tuning experience, so I’m not concerned that I’m getting the carbs setting wrong….besides I tried them all. Its done this from day one!
Anyone else experience this behavior from their mini swift?
I don’t have any direct experience with the Mini Swift yet, but since you said it is a new motor, could it be the clutch? Could the clutch be engaging too soon, before the motor hits the torque curve? I had a similar issue with a Gazelle with a brand new clutch, that it was engaging too soon. Just something to check if you haven’t already.
I took it to our local kart shop, and he put it on a lathe and removed some of the material. IAME clutches are known to engage a little early on the lower horsepower motors, and typically the clutches should be cut some prior to their first use.
Once we got our clutch cut, the starts were much better and my daughter didn’t bog down and get passed so quickly when the green flag waved.