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1981 CB750C intake boots

81CB750CTS

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New member here!

I am in need of assistance. I recently replaced the boot's for my carbs, both intake and engine sides. The boot's on the intake side keep sliding off whenever I ride. I can have them on in the driveway with no issues but as soon as I get out on the road, they slip off. Any experience with this issue or ideas for a fix?
 
Lots say that but still not in all the way. The boots are different inner vs. outer too and must be rotated correctly to line up. Most are numbered with numbers facing straight up.


Cheap crap Chinese part? Maybe that, spec is off.
 
They seem to be lined up right. But I'm going to fiddle with them this weekend. And I got Honda oem ones, which I thought wouldn't give me issues
 
Let's back up a bit. Are we talking about the ones between carb and motor or the flimsier ones that go between carb and airbox?

If the latter it could be the airbox positioning, they are fits to get right. The boots were often glued in at airbox from the factory too, maybe for that reason. You have to go around the edges to make sure the entire periphery of the circles at the back at airbox surface is properly in the boot slot, if they have not been for a while to wrinkle then they tend to want to come out.

All the DOHC airboxes give utter fits lining up and fitting things back together and why so many people go to aftermarket solutions like pods, but nothing else will make the carbs run as well as the OEM airbox, it is viewed as a mistake to not use it. The CV slide lift works much better with it because the carbs then share vacuum drop to activate slides faster. All of course must be sealed to do that.
 
They are the ones between the airbox and the carbs. I'm going to take them out and reposition them again. We're they glued to the airbox or the carbs?
 
Airbox.

The carb end clamps down and needs the OEM clamps as wider can pull the boot off due to the one only raised rib on carb end, a wider clamp sometimes misplaced very slightly to the back makes it push the boot off.

The glue used appeared to be like a simple rubbery contact cement.
 
We always used the yellow 3M weather strip adhesive on the 90's Honda CR dirtbike air boxes where the boot bolted to the plastic air box because they had a tendency from the factory to leak dirty air. It seemed to hold up very well even being exposed to air filter oil.
 
Maybe even TOO well if the old school stuff. The product is weaker now due to them pulling some VOC out that made the older version get sticky much faster than it does now. It used to be the killer product on weatherstrip instant holding, use it now and you cuss a lot, it doesn't stick nearly so quick as it used to.

Like Krylon spraypaint and any house paint, what is out there now is somewhat different from what it used to be. The companies have learned to use newer environmental regulation in order to make product cheaper, how they now recoup the redevelopment costs and make even more profit. People complain it's not the same product and they point them at the EPA. I saw all kinds of stuff do that when I was in auto parts. The carb cleaners now are virtually worthless.

Just a thought thinking about the boots.........if someone had the wrong boot there, say the later model 650 custom, both ends would be the correct size but the length may be off to make trouble, the 650 DOHC is a different engine and the points in space at back of carbs are likely different.
 
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Anyone know the MM size of the clamps? The sizes vary and I bought a complete set that said it fit but they are too small. Dangit.
Edit: Found the info and surprise it isn't 44-46 mm. Honda part number: 16219-422-000 (clamp range - approximately 48mm-52mm)
 
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