1982 XJ750 Maxim - Plate Missing in Carbs?

Isn't there supposed to be some sort of plate or cover over the top of these two air jets, under the rubber diaphragm? I'm working on this set of carbs for a friend, and I just started tear-down last night. From the videos that I've seen, it looks like there should be a plate in each carb that covers up these jets.

 

Hi and welcome to the forum. Have you opened up the other three carbs yet. Keeping in mind you will want to keep track of all the little parts, screws and everything so you can put it back together again. According to this Vid, it looks like you are missing a part from the top of that one. Check the other three to make sure it is missing or they are all missing.
https://www.youtube.com/shorts/SaEGJTDwTEI

 

Yes, that plate is missing from each of the carbs. I've got a good organization system going for these carbs - just worked through a set of PD46A carbs for a 1977 Honda CB550K3 as well. It's kind of strange that the plates are missing, as I believe the bike was running fairly well without them. I guess I'll start looking for a part number tonight.

 

As I recall it's a case of "some do, some don't" on that plate. I have 3 sets of Hitachi's and if I remember right, not all of them had it. I don't think it actually does much and may have been eliminated on some years or production runs.

 

1. Yes, it’s missing. See the threads? That’s where the screw would be to hold it down.

does it matter? Nope…….not if all 4 are the same. Yamaha used them on some, but not others. Doesn’t really make a difference.