$10-12 airbox boots (in progress)

[Guest]

A simple how-to on making your own airbox boots and saving a few bucks.
These boots are for VM26 carbs and 78 GS750 airbox. May not fit other models.

I purchased these items at a local hardware store that is infamous for high prices.
Bought at the right place, the cost could be well less than $10.00.
Note that the picture shows 8 lock nuts, but only 4 are needed.


Using a sharp blade, either a knife or razor, cut each end from the rubber
coupling, about 1/8" from the clamp groove.
Try to cut as straight as possible, but don't fret if it's uneven.
The factory cut side will go towards the airbox for a proper seal.


Here you see that I have 4 rubber boots from the two couplings.


Now we need to cut our PVC nipples. I used a hacksaw for the one pictured.
If you have an electric miter saw or chop saw, it would be easier and make a cleaner cut.
Just don't try to cut it too fast or force the blade through it.
Which ever method you are comfortable with, make your cuts about 1/4" from the end of the threads.


After cutting the PVC nipples, screw on a lock nut all the way then back it up 2 threads.
Apply plastic cement or PVC glue to the 1/4" smooth section of the nipple
and insert it into the factory cut side of the rubber boot, all the way to the lock nut.


To install, unscrew the lock nut from the newly made boot, insert threads into airbox,
and reaching inside airbox, screw the lock nut back on.
Tighten until you have a nice seal, but don't over-tighten.

In theory, these should seal nice and tight against the airbox, and then clamp onto the carbs.
I haven't finished making mine, due to not having any cement, so I can't verify if it actually works.
I'll post more pictures after I have them installed.

[Gonzo]

I like it! Hope it works out.

[twotimeGSr]

Looks like it should work fine. It might raise the vacuum pressure a bit (make it run a bit more rich) if the Inside Diameter of the threaded piece is smaller than the smallest Inside Diameter of the factory set up. I will probably face the same issue someday.

[ValorSolo]

I'll be glad when I can test it out. Still have a lot to do. Gas tank. Wiring mods.

[jesustheplumber]

only problem i can see is turbulence cause by the pipe nipple. the genuine air boots have a nice velocity stack shape to reduce turbulence and smooth carburetor performance.

[SeanMora77]

I bought a foot of fuel line, id-2" for fourteen dollars at napa. I cut the hose into two and a quarter inch sections and then taped off one end with masking tape as a guide for my kerf,"three quarters of an inch if I remember right". Then I slid one of the sections on a rolling pin, tightened the hose clamp so it wouldn't move around and dremeled a rough guide groove all the way around the edge of the tape. I then locked the rolling pin in my bench vise and took an 'A' bass guitar string and ran it through the dremel groove in a sawing motion until I made it just over half way through the hose. I fitted the first one in the airbox and the fit was just a bit too tight causing a slight distortion of the airway so I then dremeled out one and a half sixteenths from the airbox plastic which made a seamless perfect fit. I also used the dremel to bevel the the edges of the boots going into the airbox for smoothest airflow possible. A little time consuming, but saved some money and am very happy with the result.

[Eli69]

thank you mr. solo for this thread. your idea may have sent me in the right direction. i've been looking for some way to replace airbox boots cheaply and this thread came along at the perfect time. your drain pipe coupler idea is pure genius. we call them "ferncos" and use them on plumbing jobs all the time.






they're flexible, sturdy and seem to last. they cost about $6 each at hardware and plumbing stores. this size fit perfect into the airbox for a 80 1000G.








and they fit perfectly onto the carb. i carefully cut them in half by putting them on whatever was around that they fit on (first thing i found was a tube of caulk) and using one of the clamps as a guide cut it with a razor knife.







the ends of ferncos have a slight indentation for the clamp which, with a little work, will fit tightly into the airbox opening while the cut end goes over the carb and the clamps that come with it fit over that.







and the best thing is ferncos are made in the good ole USofA.







so i'll be testing this in the next few days. tomorrow is the bike drags so this will get set aside for now but i'll let ya know if it works. thanks again.

[gs850cafe]

awesome idea...if it works do it lol...i paid 50 somethin bux for mine...i been debating on pods..but i got new boots i paid for lol...

[Eli69]

yes new boots are just too damned much $. i'm trying to get this 1000 running with minimal cash, if for no reason other than to say i did. options were:

new boots - about $60
or
cheap pods and dynojet kit - about $120
or
try cheap pod filters and rejet myself - $unknown and i'd probably go schitzo and kill myself.

[ValorSolo]

Eli, I may have been over-thinking this project. I'll have to try your method when I get time.
Fewer parts which means less chance of leakage, less work and a buck or two cheaper.
I see you are using 1 1/2" for yours, I'm assuming CV carbs. And I'm using 1 1/4" for VM carbs.
The couplings I have are a perfect fit for the carbs, just haven't tried to fit them in the airbox, yet.
Maybe I can get it figured out, this evening. And post my results.

[ValorSolo]

I suppose my logic was sound, after all. The nipples are needed.
Being that the 1 1/4" nipples fit near perfect inside the airbox holes.
And the nipples are also a perfect fit inside the coupling.
This eliminates the possibility that the coupling could fit into the airbox holes.
Pity. I liked that idea of yours. Oh well, mine should work just fine.

[Eli69]

i got the bike together last nite and actually rode it around the neighborhood. breaking up at 3/4 to full throttle but otherwise runs pretty good. i'm gonna check the ignition advance to see if it's working before i go back to the carbs and intake problem.

[Eli69]

home made boots seem to be a success! my first test rides had the motor breaking up and losing power at about 4500 rpm. i assumed failure of course cuz that's how i am. long story short - i read the plugs and they showed rich. i took out the k+n filter which i had over oiled and went for a spin. holy sheep sh1t! that bike's fast and pulls all the way up to redline. i'm now recleaning the filter and will attempt to oil it correctly this time cuz i think it's a bit lean without it.

moral = cheap home made airbox boots are otay!