Reply To: QD15 Carb Kit – needle & seat compatibility?

[frankr]

Some things to consider.

There were several part number changes along the way.  The original n/s had a metal needle.  That was replaced with a soft tip needle.  When the soft tip needles were found to stick in the seats of the gravity feed carbs, the little hairpin clip was added to drag it down off the seat.   The gas guzzling fat 50 and 75 hp motors had to deliver a lot more gas per minute than the smaller motors.  Whether or not that caused a larger seat, I don’t remember.

Anyhoo, bottom line is the current number is a best attempt to standardize the part.