Throttle, Wide bottom bracket and more...questions


New Member
Sep 5, 2018
Building a 79cc Pred Dyno motorbike. This is going to be a street bike for my father (me) and son motorbike project.

Here are some pics:
and pics below:
79cc_1630.jpg 79cc_1632.jpg 79cc_1617.jpg 79cc_1619.jpg
79cc_1623.jpg 79cc_1612.jpg

Which throttle should I get?
I see some with a 90˚ wheel and some without. Which do you prefer and why? Which vendor do you recommend?

Which fuel pump do you recommend and why? Vendor?

I got a 19mm Mikuni for this project and am wondering what the jetting should be and where to get the jets?

I am building an exhaust manifold/header and want it to exit behind the rear axle. What muffler do you recommend? This is going to be a street bike for my father (me) and son motorbike project.

I need about 12" or 305mm to clear the full width of the engine pull start on one side and the cent clutch on the other side...what are you doing to get this width? Or what is the widest bottom bracket for 68mm that you have found? I will get the American to standard tapered cassette bottom bracket adapter. If there is no really wide BB which cranks do you recommend for bending or cutting and welding to make them work? Which vendor?

I am thinking of drilling and tapping for a fuel pump vent pulse in the area on the PTO side that looks like it was meant to be for a filler or the like, but is blocked off in the casting. I am planning to drill and tap for the brass fuel line fitting and can also use it to fill oil at oil change time. Any thoughts about this?

I know I will have more questions soon! Thanks so much for your help.
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