some porting


while my derbi motor was apart i figured i’d tinker around with some porting. i’d like to race this motor in the spring/summer, so i want to see what this kit is capable of.

here’s what i planned for the cylinder (65cc pyramid reed metrakit).
red goes gone
i ended up just raising the exhaust 2mm and widening each side 2mm. i want to raise the transfers 1.5mm, but couldn’t get in there with a dremel. it might have to be hand filed. anyone have porting thoughts on that? what do you guys use to get at the innards of a cylinder?

quick bit of porting advice: these dremel tungsten carbide bits turn cast iron into butter.
they’re a bit pricey ($8+), but a totally worth it. having both the straight cylinder and the tapered one is really nice. i clean up after those with a sanding drum. it’s a sweet 1, 2, 3 cast iron combo.


3 Responses to “some porting”

  1. 1 vic

    never used one myself yet, but this is what people who go nuts porting use so i’ve heard.

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