Main jet thread size

[baz]

Anyone know off hand what the thread size is of an Amal concentric main jet?

 

[acotrel]

The needle jet thread in Mk2 Amal is zero BA, so the thread on the main jet will probably be BA, but smaller.

 

[baz]

The needle jet thread in Mk2 Amal is zero BA, so the thread on the main jet will probably be BA, but smaller.

No it turned out to be 1/4" BSF

 

[acotrel]

No it turned out to be 1/4" BSF

That information might come in handy. Some Japanese bikes used Type 6 Amal carbs with British jets, some had Mikunis with Solex jets. My Mk2 Amals are very similar to large Mikunis, same main jets as TT and GP Amals. The needles in all of them are the same diameter on the parallel part. And the lengths of the needles are the same for the same size venturi. Mikuni give a better range of needles. I don't trust Amal. I did not ever know how to tune them when I was a kid.