Z1OwnersClub GB

Gents

I have a spare set of carbs - Mikunis - and noted that the needles have a small degree of vertical play (about 1mm or so) and "wobble" about somewhat when the air vlave/slide assembly is pulled from the top of the carb.

Is it deterimental that the carb needles have this degree of play/wobble? I seem to recall that other carbs have a small spring in the plastic seat - the green or blue plastic thing under the large slide spring - which reduces this effect. Needles here have no vertical play and only a small degree of lateral movement. I know these Mikinis never had the small spring so I guess any slack could be taken up by shims if the needle has too much vertical or lateral play.

Sounds normal..
Won't cause a problem.

Cheers for that. My concern though is that if the needles have vertical play, that clearly could affect their position in the jet holder - if they move about vertically - and thus affect the mix.

Ive been here myself.

Surprisingly, it doesn't seem to matter. If I'm remembering it right the earlier Z carbs did have the springs holding the needles in place, but they got rid of them by the time they built my Z thou (1977).

They must have done it on purpose. I don't know if the vacuum keeps them seated or something. I guess it does mean that the needles can float about so won't be so likely to rub on the needle jets if they're not perfectly aligned.

Yes - certainly the case that some carbs have the small springs holding the needles and some do not. Can't think the vacuum would hold them down as the vacuum would pull them towards the engine if anything.

I don't think it is a big deal, but I just wonder that if the vertical play is too great then the needles may not seat correctly in the jet holder or hold up within it fractionally.