Athena Boardtrack Racer build

Actually I'm wrong, there's also interference fit. And even the stuff held by set screws have a loose interference fit. I've had to hammer pulleys on with a dead blow. Clean shaft, clean bore, light oil on both and it still needs some gentle taps.
Most of the more powerful small dirt bike engines have a spline shaft for the counter sprocket.

BUT.., just looking on some shifter kart part sites and I do see a few counter sprockets with smooth shaft fit with grub screws.
Time will tell on this clutch. Some of the newer 2T bicycle engines put out a fair amount of torque.
The Relli just arrived. This sucker is sweet. Not sure why so many were trash talking the Gomax minarelli. Honestly this is one of the best looking motors ive seen. flawless bottom end. Great cast quality on the cylinder and all the hardward is pretty stout.
damn thought i was gonna be able to fire it up. But I got bigger issues. Have to rebuild the first 6in of my pipe. I also have to cut off my motor mount and somehow position the motor flat and then see where i can weld the motor mount. With the new motor position. I must also reposition or rework my head cooling system. It falls 1 in short of the head🤬
So while porting my Relli cylinder. I noticed the bore had cross hatching in it. So I took my piston without rings and dropped it in the cylinder. it slide effortlessly through the jug. Which means. With everything that was done to the motor already with upgraded parts. Gomax even honed the cylinder in their kits. If you get one of these kits everything is 100% done. You can start it right out of the box if you want. Very impressed with the go max. just saved me another $40 on a flex hone. Dont care what anyone says. Smolik minarellis are expensive and you have to pay extra for honed or ported cylinders. Gomax has everything the smoldik motor has at 1/3 of the price. If you want a fast $300 motor with 6hp out the box. Gomax is your ticket. This motor is the REAL PHANTOM KILLER.
Just got done porting the minarelli. Portmatched everything. widened the transfers on the case and adapter plate. Also stuffed the case. The relli hit 10,500 rpm stock. It now hits 12,500rpm and with the wrong jetting. need bigger main jet. Im starting to feel this little moster might be to fast. But thats what I live for. If Im not afraid of it. Im not having fun.