Keihin strange float needle question

Hi! I've been working on restoring a 1981 KZ750 LTD for the last year and a half and I'm very close to finishing. In my garage I was able to get it to start and idle somewhat decently. Last weekend I took it for a quick ride. After a mile and a half, the carbs started overflowing badly and I had to push it back home.

I took the carbs apart yesterday to clean the float valve seats and adjust the float level. After doing that, I put the carbs on a stand and filled them up. They overflowed very quickly. So I drained them and took them apart and out of curiosity, dug out the old float needles (I had replaced them with the ones from the rebuild kit a year ago when I rebuilt the carbs). They are very different from the ones I got with the kit:



The needle on top is the (presumably) original needle. The one below I got with the KL rebuild kit. It has an internal spring. When I first installed them I thought they would work just the same despite the different design. Clearly not the case.

I put the old needles and the floats seem work perfectly now (getting the level properly set has been another story entirely). But I have been doing a lot of research online and it seems the only needle sold for these carbs is the newer, internal spring type.

I was thinking that maybe the newer needles might work better if I remove the little clip that goes over the float tang? Or is there another trick to make these work?

I just rebuilt the carbs on my 82 KZ750H with the Keihin carbs on it. All 4 of my carbs had been previously opened and I don't know what (if anything) has been done to them before I bought it. That said, I had the bottom style of float needle in mine.

One of the 4 springs was really stuck, I had to free it with needle nose pliers then soak it in carb cleaner while working the needle for a while before it freed up but eventually it came free.

Those needles seal up perfectly in my carbs. In your pictures they look to be different in length from the original needles you removed. Likely you will need to adjust the tab position to get the new needles to seal. Leave the little clip on them it makes them easier to handle and remove.

If the old needles are sealing up fine I suppose you could leave them in there, the tip of the needle looks okay in the pictures and you would have a spare set on hand if any start to leak in the future.

It's what I was thinking, leave the old needles there, but since I haven't found any needles like that online I was getting worried about getting a few spares. Three of the old needles look fine, but one had a slightly distorted point. It seemed to get better after use, I guess the gasoline made the rubber tip swell up slightly.

The old needle is a little bit longer, so I had to bend the tab significantly to get the tang to push on the new needles, and they still wouldn't seal. It's like the float can't apply enough pressure to push on the needle spring? I'm thinking maybe the floats I have are not original either and that's why they work better with the old needles.

I spent a few hours last night bending the tang back and getting them to proper level with the old needles, and two carbs are still way out of whack. I'll try again tomorrow.