Hi Ken,
I have bought aftermarket carb kits for my mc18 88’ and only used the pilots and main jets and seals/ O rings. I was unsure if the needles supplied were an exact replacement.
I think the needles supplied were for the 89’ year carburettor.
The best kits are from Keyster Japan which have exact replacement needles J3EA for left and J3EB for the right.