Hi there getting ready to strip and rebuild the carbs on an NC21, does anyone know which parts from other models are the same particularly the float bowl gaskets and the vacuum piston cover seals?

If no-one on here comes up with a direct answer you could try cross-referencing part numbers. For example look up the Honda part numbers for the NC21 gaskets and seals, then go the Fowlers website or CMSNL and check part numbers on other Honda models. Sometimes simply putting the part number into google gives useful information (sometimes).

The NC21 and NC24 carbs are essentially the same, the only real difference being that the NC21 should have 112 jets front and 115 jets rear, whereas the NC24 had 115s front and rear in standard form.

However, this won't really help as the NC24 only had an 18 month production run so parts are even rarer than NC21 parts.

Just pulled up the carb parts lists from CMS web site for a 1987 NC21 & 1987 NC24, the gasket set for both is "16010ML0014" at 66 euros per carb so that won't happen. Important thing here though for NC21 owners is that the gaskets are the same for both according to CMS which might make it a litte easier to source individual parts. Someone on F-book stated he used a carb gasket set from an NC30 on his NC21, sounds feasible anyone else done this?

NC30 gaskets are slightly different. As far as I can remember the bowl gasket is a different size and the O rings are also slightly different. It may work but it won't be correct.

OK probably best to try for the correct ones for the bowl and other specific items to be safe, not bothered about O rings though. When I rebuilt my Hornet carbs I just measured the Tees, the bore they fitted into and O rings to identify them then bought them separately for pennies obviously making sure they were the correct material for petrol.