Removing airboxes

Matt Isaacs

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Hey all,

I've replaced the airboxes on my 1980 Special with Uni pods. A couple questions:

What do folks do with the "T" tubes that run from the bottom of the carbs to the bottom of the boxes?

Do the pods work okay with sidepanels?
 
Hey Matt, I believe your talking about the crankcase breather tube that comes from the back of your head to your filters, they make a breather filter for it ,you can get one and a bracket for it at mikes xs! Also has a one way reed valve for it if that’s the way you want to go! I have also seen the tubes tapped into the bottom of the pods,heard it’s ok but not sure! I’m sure one of the gurus on this site can help you more! They are a great bunch of people with the greatest knowledge on XSs! The side panels will help keep the weather and road debris off them!
 
Don't throw out those airboxes.
If you get tired of "not running the greatest". You'll want them to put back on. I like wrapping the stock air filter frames in Uni green foam. There's pretty strong circumstantial evidence airboxes are worth at least a couple horsepower over pods on CV carbs.
With experience and some technique they go off and on easy.
 
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One of the easiest, cheapest, and best solutions for the oil breather line is to add a power brake check valve to the end. Poise it over the UNI pod and any oil vapor or drips that may come out will simply be absorbed by the filter .....

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You'll probably want to replace the breather hose as well. Your original is no doubt hard as a rock and will be difficult to re-direct and work with. MikesXS sells replacement breather hose that is very nice, exactly like the original stuff.
 
Don't throw out those airboxes.
If you get tired of "not running the greatest". You'll want them to put back on. I like wrapping the stock air filter frames in Uni green foam. There's pretty strong circumstantial evidence airboxes are worth at least a couple horsepower over pods on CV carbs.
With experience and some technique they go off and on easy.

I took out the airboxes mostly for ease of working with the carbs, and to a lesser extent aesthetics. But with them off, I see I'm not gaining much in the looks department with the ugly battery box and other crap still there.

Any tricks to getting the boxes back in besides just fiddling with them for a half hour?
 
I took out the airboxes mostly for ease of working with the carbs, and to a lesser extent aesthetics. But with them off, I see I'm not gaining much in the looks department with the ugly battery box and other crap still there.

Any tricks to getting the boxes back in besides just fiddling with them for a half hour?
YES! Spent years figuring out these "tricks" I'm a slow learner. clean and lightly file the corner on outside of intake bell on carbs. use silicone grease on all joints, I like sil glyde. Put one filter on intake bell of carb leave it slightly splayed out. insert the cross tube lightly and tipped forward. now do the same with other side. Push them together. Install rear screws. The two top screws are the hardest. I keep meaning to get some pointed body screws to replace the square end stockers but prefer the stock 10mm bolt heads. A bit of wiggling and a small phillips screwdriver in the holes will line up the bracket and air filter to insert the bolts, a large screw driver levered between filter housing and front of battery bax can help with alignment also. If you're lucky you have the spring steel clips that hold the filter frames against the housing. I cut new gaskets if needed out of some foam sheet. but check what you use for gas resistance.
 
If your rubber is hard a bit of heat gun or hair dryer softens it for a while. Winter green oil softens it for a longer period.
 
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I'm still working on that, lol. So far they remain just a royal P.I.T.A. to install. Besides blocking easy carb access, I also don't like the way they require cramming all the wiring in. I've retained the airboxes on my new-to-me '83 just because people say they work so well. My other (and 1st ever) 650 has only had pods from day one so I'm interested in finding out if the airboxes are indeed better. So far, I see little if any difference in the performance between the two machines. I do have pods already for the '83 so eventually I should be able to get a back to back comparison between them and the airboxes.
 
One thing I have discovered about the BS34 airboxes is that Yamaha used a barely long enough screw (M6 x 30) for the lower rear box mounts. It barely catches by a few threads. Best you change that to a 35 or 40mm long screw/bolt. I went with Allens. There's plenty of room and clearance behind where the screw threads in for the extra length.
 
A couple years ago with 5T's carb jetting advice, removing a stock 78e airbox and switching to pods was very successful.
It was a strong fun runner .
I believe many XS owners ditch the stock airbox halves because of the cramped fuel line area difficulties and damaged original rubber components. Which are very hard to find.
My own experience was positive. Bearing in mind that proper installation of the carbs becomes critical as they like the additional airbox support.
I sourced pvc like black plastic tube right out of the hardware store garden sprinkler aisle.
It is about the right size. A little heat and it bends to whatever you need.
Incidentally, I am out doing my parts sourcing rounds in Ptld.. Ya no parts anymore this way LOL but look at this Pod air /turbo set up !
-RT
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As you will see Matt! Different setups on different types of bikes! Get to know your bike and how it runs best wichever way you go! Remember you might need to rejet if you go to pods and adjustment of your air mixture screws! There is a good write up on this in the tech section!
 
YES! Spent years figuring out these "tricks" I'm a slow learner. clean and lightly file the corner on outside of intake bell on carbs. use silicone grease on all joints, I like sil glyde. Put one filter on intake bell of carb leave it slightly splayed out. insert the cross tube lightly and tipped forward. now do the same with other side. Push them together. Install rear screws. The two top screws are the hardest. I keep meaning to get some pointed body screws to replace the square end stockers but prefer the stock 10mm bolt heads. A bit of wiggling and a small phillips screwdriver in the holes will line up the bracket and air filter to insert the bolts, a large screw driver levered between filter housing and front of battery bax can help with alignment also. If you're lucky you have the spring steel clips that hold the filter frames against the housing. I cut new gaskets if needed out of some foam sheet. but check what you use for gas resistance.
Thank you, ggGary and all, for your generous help. This list is the best. Happy new year!
 
Don't throw out those airboxes.
If you get tired of "not running the greatest". You'll want them to put back on. I like wrapping the stock air filter frames in Uni green foam. There's pretty strong circumstantial evidence airboxes are worth at least a couple horsepower over pods on CV carbs.
With experience and some technique they go off and on easy.

Our airbox threads often sound like it's a simple "yes or no" decision between them and pods/uni's; but years ago, XSJohn worked out some mod's for at least the later airboxes that offer another alternative. I'm sure the details are still available on this site, but IIRC they involve adding a third inlet tube and removing internal ribbing that forces several changes in airflow direction inside the boxes upstream of the filter media. I did these mod's on the airboxes on my '82 when I still had BS34's on it, plus trimmed back the rear flange on each side cover to unshroud the inlets to each airbox. The carbs already had XSJohn's needles and the larger jets he recommended, so no way to tell exactly what difference these airbox mod's made vs bone stock, but it seems logical that they reduced restriction on the inlet side of the carbs a bit while still preserving the stock "look", the fore-and-aft carb support and the weather protection lost with pod/uni conversions. It ran very nicely; I'm sure I'd still have them if I hadn't done the Ninja CVK carb transplant thing.
 
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Our airbox threads often sound like it's a simple "yes or no" decision between them and pods/uni's; but years ago, XSJohn worked out some mod's that are possible on at least the later airboxes that offer another alternative. I'm sure the details are still available on this site, but IIRC they involve adding a third inlet tube and removing internal ribbing that forces several changes in airflow direction inside the boxes upstream of the filter media. I did these mod's on the airboxes on my '82 when I still had BS34's on it, plus trimmed back the rear flange on EACH side cover to unshroud the inlets to each airbox. The carbs already had XSJohn's needles and the larger jets he recommended in them, so no way to tell exactly what difference these airbox mod's made vs bone stock, but it seems logical that they reduced restriction on the inlet side of the carbs a bit while still preserving the stock "look", the fore-and-aft carb support and the weather protection lost with pod/uni conversions. It ran very nicely; I'm sure I'd still have them if I hadn't done the Ninja carb transplant thing.
I actually am using XSjohns conversion on my airboxes! Yes it does run nicely,it added a bit more zip and better response!
 
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