02-09-2022, 11:28 AM
Ed, nobody can even give a good ballpark without info on the track, your weight, Etc. I was a Go Kart dealer in '61/'62, and sold more than one 1200/Mc7 setup. Our track was short and tight, and we usually set them up geared about 10-78. which translates to about 9-70 or 9-72. We always discouraged using a 9T top gear, due to excessive chain wrap and chain wear. I ran open motors, so I used about 10-76 on my kart. I weighed 125 at that time. Heavier means you need more axle teeth for decent acceleration.
Remember, if you plan to race, a good percentage of the early Macs around the country have been nine ported, and you'd be at a serious disadvantage against a boost port engine.
At least you run a GK 1200, which, for me, is the best REAR engine kart ever made. It needs Go Power magnesium wheels and an aluminum axle to lighten it up. We ran the 1200 as an A Super, a B Super, and with triple Macs as a C Super. It handled superbly no matter how we ran it. Ted
Remember, if you plan to race, a good percentage of the early Macs around the country have been nine ported, and you'd be at a serious disadvantage against a boost port engine.
At least you run a GK 1200, which, for me, is the best REAR engine kart ever made. It needs Go Power magnesium wheels and an aluminum axle to lighten it up. We ran the 1200 as an A Super, a B Super, and with triple Macs as a C Super. It handled superbly no matter how we ran it. Ted