I think you're right. He's Brit, so I kind of just trusted him (hard to imagine someone with an accent that thick being full of it), but I think you are spot-on correct!
Originally Posted by KCvale
Just for your reference there is no such thing as 80cc, you see them listed as 66/80cc but it's Chinese BS and they are all ~66cc in actual displacement.
Was this an experienced builder with multiple builds, or just a guy that built a bike and couldn't make it run right so he dumped it on Craigs?
Well there is a huge red flag warning right there.
It is in your best interest to just get a 1 gallon gas or two for bike use and mix good quality gas with your average auto supply stores 2-stroke oil as mixing 'in the tank' is always ifffy.
32:1 is a good mix, that is 4 oz (1/2 a cup) of 2-stroke oil to a 1 gallon of gas.
Your builders advice even at 1/2 an ounce to you 1/2 gallon tank was absurdly low at 128:1 and liable to toast your engine in short order.
Trying to run at a 128:1 mix will do that and the damage may already be done.
Idle with the clutch in is idle, you set it on the carb not by the cable.
Hope that helps.