Advice on squeezing carbs into boots

member14827

XS400 Member
Messages
29
Reaction score
4
Points
3
Location
Virginia
So, I've got a new set of carb boots on my 80 XS400G. I'm ready to mount a set of stock BS34 carbs which are, obviously, bolted together as one "unit."

Any advice on how to finagle the carbs into those boots? It's so tight and I can kinda rotate one in, but never the other, and never both at the same time.
 
Mine were just a matter of wiggling up and down vertically while pushing forward forcefully towards engine and eventually they popped in past the lip
 
Be careful with aftermarket boots, the lip on the carb side tears easily. I mustve have gone through 3 sets in the last couple years. Im sure the boots will still have a decent seal with a torn lip, but they wont hold as well. The 360 (what I have) came with boot cages so that helps. They had to be slightly modified to fit aftermarket 400 boots. I think 360 carbs are heavier as well.

I like to mount each boot on the carbs and let them settle for a while. I have used a bit of bearing grease on the inside of the boots to help them slide on the carbs. Obviously, bearing grease wasnt the "proper" choice, its just what I had nearby at the time and wasnt worried about it.

I will use a ratchet strap around the engine and ratchet each side one at a time. One side will always pop in first and then you should try popping the other side in by hand at the same time. It can be tricky. The rubber will eventually break in and then you wont have to do this anymore.

If you sit on the bike, you should be able to rest the carbs on the boots and push down a bit and rock them into place. I prefer using the strap to avoid awkward body positioning and upsetting my spinal region.
 
Thanks, Mike. They are aftermarket boots and they are a TIGHT fit. I considered some kind of lubricant to help getting them into place, but wasn't sure what would be "safe" to use, or if any of you more experienced folks had success and/or issues with that. The ratchet strap is actually a really good idea -- I'll definitely try that. I also considered using a heat gun, carefully and on a low setting, to soften up the rubber just enough to make a difference. It's good to know that they'll break in and eventually it won't be a problem. Once I get it, I'll let y'all know what worked.
 
I use a thin coat of silicone dielectric grease. Won't degrade the rubber.

Sometimes pulling the carbs into the boots by reaching around the motor from in front of the bike can help.
 
I use a small board against the mouth of the carb and the middle of the frame and they pop right on with ease. I also only have used stock oem yamaha boots.
 
Back
Top