TOPIC:

You have to be mindful of how far and what angles they are in the box. Mine are 3/4" on the two inside ones and 3/4 for the outsides with a angle cut directing the intake. It's amazing how 1/4" can make in difference.
Steve

Yeah, I know. Unfortunately, the boots I need would have to have a 45* angle to them, as that is the angle of the airbox versus the mouth of the carb, in order to sit straight. The length is fixed by the ribs on one end (where the flanges bolt to the airbox) and the clamp surface on the other end (where it fits over the mouth of the carb).

I received the silicone boots the other day, but will have to slightly modify the airbox to get them to fit; the airbox outlets are 2.25", and the OD of the silicone boots is 2.5. The ID of the boots is 2.125, which almost exactly matches the OD of the mouth of the carb. If it's snug, I can grease it and force it on; if it's loose, it won't be by much, and a hose clamp will easily take care of it. I'll post pics when I'm done.

They have silicon hose with angles . 22.5-45-90*. You want them tight. They will shrink slightly. I'd try them as they are.
Steve

looking for part number 14073-1061, 82/750 M1, 83/750 K1, 1984/750 K2

Bikebandit $25 - ETERNAL BACKORDER, really surprised no one is making this replacement boot.

Yep, got the 45* ones just last week. I tried to fit them to the airbox, but it was no-go without folding them in on themselves, which leaves a gap. The fit on the carbs seemed to be good. They're too long (4" legs on either side of the elbow), so I'll have to cut them down.
I hadn't looked at BB for the ducts, as I just automatically assume nobody has these. The bikes they used them on were only produced for two years, and I don't know that they made a lot of them. So, does the fact that they have a price on them mean they have them, or not?

That's how I get mine in and out, I fold them into themselves. I reach in and pop them back out. Nice tight fit.
Steve

Any concern about the lack of venturi throat to the silicone boots? I've heard that makes a big difference to flow and velocity.

As long as they aren't blocking anything, there's no problem. Inside the box is what I was talking about. Look at your boots then figure out what angle you should cut the outside ones and have the two center ones like the stock ones.
Steve

I'm sorry, I must have forgotten to mention this is the CSR750, aka the KZ750M1 as noted in my sig, which is a TWO-cylinder. I've since found out the (wrong) boots it came with were from a KZ750B, which was also a TWO-cylinder, but had a different shaped box, which makes the angle of the boots wrong for this application.

You might want to Google 'Moog mod' and save some trouble.

Cut them as close to the stock angles as possible.
Steve

AtLarge: Wish I'd seen that before! Should have known to hit up Biquetoast first... Ah well, these silicone elbows will work just as well, and they were quite a bit cheaper ($13 each, vs $27).

Swest: Might you happen to have a spare CSR750 or 750LTD boot from which I could get the stock angles? LOL! I'll try to figure it from the carb and airbox.