Amal Carb. - Tuning?

OK...this is going back to the Puch Magnum MKII 70cc upgrade that I posted about. I found an intake for it. It's a 14mm "tall" Puch intake. It has a round flange instead of a square one, but it does work. The carb in these kits are the Amal "tunable" kind. There are two adjustments on the side. The top one is the idle "screw." Is the bottom a main mixture screw? If so, how is it adjusted?

I'm a bit disappointed the the overall performance so far. There is improvement, but not as much as I expected, although I am not gunning it too hard. It will nail the ol' speedo, however, the acceleration isn't much better until you hit the midband rpms.

Re: Amal Carb. - Tuning?

I did the same upgrade on a 1983 Magnum II. I forget which way is which but when you adjust the mixture screw (with a 5/16 inch nut driver) when the ped is running......if rpm goes up your are going lean. The other way will be rich. If I were you I would also "modify the intake port on the bottom of the manifold a little to match the square port on the cylinder.

Another tip: Go rich on the mix, especially if your air filter is pointing toward the front tire. At high speeds too much air will be forced into the carb and the engine will bog.

Do a "search" for "Things not explained" in this forum. I had alot of fun doing this upgrade.


Re: Amal Carb. - Tuning?


Thanks for responding. What kind of performance gains did you see? Did you use this intake? Did the mod on the intake help at all?



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