(agent orange special) What could possibly go wrong?

well the little 29cc bike is being retired. it is a sad day.

BUT, dont fear, my projects always come back better.

in this case, i have an almost brand new 5 hp briggs. it has less than an hour of use, and looks factory, no dents not even any dirt packed in the fins, it just happens, that it will fit in the frame of the old 5 speed bike. now i know what you all want to know, and that is, it it gonna have gears? that is a definate yes. i feel that with this power, the gears are gonna be fairly shallow, but i have an idea to combat that. it is gonna be a street bike, as much as that pains me, but the casette doesnt have a creeper gear. i did the math, and i need a 6 to 1 for dirt use, but that will be very hard to make. i can make an about 5.5 to 1. (with a jackshaft) which should work ok. im gonna have about 65 ft lbs of torque, and with pedals, you can make more, so i hope i wont break the chain. its gonna have a centrifugal clutch, because there is no room for a cub cadet, or belt clutch. im gonna leave the governer in, and leave the engine 100000% stock. i need help connecting the throttle cable, on the below tank bracket. i really need a picture. speaking of pictures, i have mocked up the engine. let the build begin.

I am open to any advice, from the people that know about high power, and gears.
could every one of the chain link pins but one be tig tacked in place? i think i have the skil to prevent siezing the chain. than i would rip the links in half instead of pulling the pins apart. ive had both happen.