Air box why you should run one

While appearing to be no more than a weather proof container for an air filter, the air box is actually a highly sophisticated, but under appreciated, component that's often the target of crude efforts to boost a motorcycle performance. Besides preventing as much dirt or water intake as possible. Airboxes have several other important jobs, they quite the intake tract, smooths out the velocity entering the carbs. The engineers know more about how all this works than you and I will ever understand. Remember this is not a small block chevy where putting an open air filter help. IE chevy has down draft carb, we have CV side draft carbs. Using pods can actually rob the engine of power exept maybe at top end, having to experiment with jets is a never ending quest . I know folks out there will say their bike runs great with pods, I had a friend had put pods on his Suzuki 750 he loved them ... or so he thought. He rode my Kawaski 550 LTDF1 with stock airbox.A week later he put stock airbox back in ... he no longer had a bog taking off... and switching jets his mileage went way up. Before he was always adjusting his carbs, fouling plugs etc .... this is one reason I' m no fan of pods. I have a stock air box on my 82 XJ750R seca since taking carbs to church I have not had to touch carbs only ride.

 

it makes life easier

 

Except when you want to pull the carbs

 

It's easier to pull the carbs with the air box there than it is to tune them without one...

 

Le sigh. Viva la revolucion, Pods es presidente. Pods es muy guapo.

 

If you do your carb rebuild correct the first time, you should not have to keep pulling carbs off... I can have mine off in 15 min and about 20 min back in with the stock airbox ..

 

Pods are strictly an image based trap that many fall into.
Anyone seriously interested in increasing performance would not even consider using them.

I have lost count of how many have gone to the point of tuning for pods on the dyno only to have them not work on the road.
And constant complaints about not being able to tune the bike with them on.

~Ghost

 

^^^+1 I too know a few "dyno tuned " an engine and pulled onto the street and power band was all over the place. My whole point is the engineers that designed the set up , had to work within the EPA, Noise, Fuel economy requirements ... and still deliver Horsepower ... I think they got it figured out. I see sooo many posts about putting pods on ...and it is ALWAYS going to be the same replies PUT stock Air box in ...

 

Also, a stock paper filter--no foam filters!

 

Why?

 

Foam filters flow way too much air. My XJ700 had a foam Uni filter in it when I bought it and I could never get the carbs right until I put in the stock paper filter. The foam filter will probably require a larger main jet to prevent it from running too lean at higher rpm's. Opening the pilots screws will help at the lower rpm's but for riders that like to stay in the higher rpm range a larger main will probably be needed. When I installed the paper filter I rode about 20 miles and then read the plugs and they were sooty black (almost to the point of fouling) indicating a much lower flow of air through the stock paper filter. With a stock main jet and properly adjusted pilot screw settings I was able to get the carbs set well and now have light brown plugs, almost instant starting, and greatly improved mpg.

 

I have the best reason why not to run an air box. Cause i and others like me just dont want to. Image, styling, performance, who cares. We arent racing these things. If we were... pods are great at wot. Better performance? Maybe maybe not. Who really cares.

Imho, this argument is tiring. People do what they want. For anyone that installs a luggage rack or talk about a wind shield, where are the performance gains from that? There are none. Its just extra weight, loss of aerodynamics amd the center of gravity is off.

 

The pod horse is dead already stop beating it!

PS: my pods are on order !

 

Pods work fine if you know what you're doing.. If i wanted performance i wouldn't buy an XJ to begin with! Face the truth.. The only reason anyone on here truly has to run an airbox is if they can't get pods to work, because you'll get very limited help here. Strictly because instead of having an intelligent constructive conversation about how to tune, you'll get all the airbox high horse goons ganging up on you to throw your airbox back in.

I understand the purest aspect of older bikes, but not every bike needs to be restored to bone stock. If someone wants to build a motorcycle their way, let them. Don't preach your religion on them, nobody needs saving. I'm sure nobody came here to ask for tips how to tune their pods with hopes that the best answer is "Put your airbox back in". If they don't know how to tune than that's on them. That being said, I do agree that if you put a pod against an airbox in a race, the airbox will win. It was designed great, theirs no performance gains for sure. I'm not here to deny that fact, but good lord people, let them be creative. This cookie cutter nonsense is getting old.

 

So sorry to offend the "expert pod users" , Go look at many newer bikes they have some form of an airbox , I see the airbox is not some sexy piece , but I really hate saying this , these carbs are designed to run with an airbox. Amal carbs you see on many British bikes are a different design or any non CV carb will work fine with pods. As I stated my friend was constantly pulling carbs changing jets, he even went to a stage 2 kit , his bike would bog on take off or would scream at top end, but sputter at lower speeds. When he went back stock his bike ran perfect and he did not have to mess with his carbs . Best of all he could ride in the rain, when he had pods he got caught in a big rain storm his engine got flooded with water had to wait 2.5 hrs under an over pass for it to dry out . My post was not aimed at showing any hate towards anyone , it your bike do as you please , but remember many folks on here have as the old adage goes "been there done that" maybe it will save some from making the same mistakes other have made.

 

CV carbs are not meant to run without an airbox. If you want to run pods, then retrofit some carbs off an early CB750 or KZ that have slides operated by the throttle linkage rather than via vacuum and a butterfly. I don't care how "good" you think your CV carbs run with pod filters, I assure you, it is crap.

 

Ma! Steber called me a "goon"!

 

hi lads.
I had the first xj 750 in Ireland in mar 81. within months several mates were racing both the 650 and 750s.
we tried everthinwith pods ,bigger jets. you name it. nothing worked. they just ran like shit what ever we did.
back to standard carb and airbox.perfect
not a bother and they stayed balanced, and didn't draw water in the rain.
go figure.
,

 

Well, let me speak from the perspective of a person who sells pod systems (so I have an economic interest in promoting them) as well as the associated parts that will typically be needed when using them (jets).......I say this up front so that there is no room for error in the motives that I have.

Pods look cool. Their bright, straight-line appearance "extends" the visual aspect of the carbs/intake manifolds and creates a long-run, very mechanically-sexy appearance. And they add to the "airflow" sound that combines with all the other mechanical sounds that these engines/bikes produce. They are very "hot-rod, old-school" in both appearance and, as is common with such modifications, can increase top-end performance.

Pods are horrible from a tuning/ridability/maintenance aspect. Not because the pod filters are defective in any way.......they tend to be engineered just fine and perform exactly as advertised......it's just the air intake set-up is just one small part of the bigger "engine system" that was designed and engineered by Yamaha to work "all together now" with a restricted, buffered, controlled air intake flow. I suppose, if they had wanted to, they could have designed "the system" to use a free-flowing intake system, and it would work just fine, but they didn't. So it's not just the airbox, but the carbs (type, style, operation, jetting, a thousand small things), the cylinder head design, the compression ratio, the cam timing and events, the exhaust system, etc. that are all designed to work in harmony with each other. The whole ying/yang thing. Very far eastern........


There's a story (rumor) out there.....and I believe it to be true.....that Harley was so impressed with Yamaha engineering in that era, that they bought a couple of these bikes to take apart and "reverse-engineer" to try to figure out how to achieve their level of performance, off-the-showroom-floor, at such a low price point. After a bit of study, the engineers reported back to their bosses: it ain't gonna happen....what Yamaha has figured out is how to mass-produce a blueprinted race engine for street use, and we can never afford to even attempt to achieve that.


And that's what the whole pod issue really boils down to: you're stepping into a cage match against the Yamaha engineers of old who figured out how to mass-produce a blueprinted race engine system for street use. And although a small change here and a small change there might not seem like a big thing....and, under certain situations and conditions is NOT a big thing......from an overall design and durability/ease-of-use/reliability standpoint, just leaving the system alone and making sure that it is performing as designed (i.e. keep the valve clearances in spec, follow the proper tune-up procedures and schedules, etc.) is what will get you the best OVERALL performance.

A lot of inexperienced people see pod filters and think "way cool!" and since it's a mechanically simple change, they go for it....and then run into all of the aforementioned issues. But they have a good-looking system while they are doing all the tinkering. So us old "experts" try to warn people of what they are getting into, and give them some practical guidance (first and foremost, if you're going to do the change, DON'T THROW YOUR AIRBOX AWAY ONCE YOU REMOVE IT!) and "useful discouragement"......the better safe than sorry approach, you might say.


If we could produce chrome-plated airbox boots, maybe that would solve the problem.....


Most people go into the situation with the thought that THEY are going to exert CONTROL over this little engine, and force it to produce more power. And what they don't appreciate is that it's a losing bet. They're going into Thunderdome against an opponent who will not and cannot relinquish control, because it was designed in such a way that prevents such actions.

Reminds me of a lesson from a biology course I once took. A virus infects a cell and takes over the "machinery" of the cell and uses that machinery to make more copies of itself.... it "hijacks" the workings of the cell. The cell tries to RESIST such changes (the "immune system" response). Clever viruses figure out a strategy: infect the cell with a long-lasting toxin which kills the cell (and would thus kill itself, too), BUT ALSO PROVIDE A SHORT-LIVED ANTITODE TO ITS OWN TOXIN! So.......as long as the virus occupies the cell, it provide constant (as needed) short-term antidotes to its own long-term toxin. As soon as the cell "figures out" how to evict the virus, the cell "wins the battle" but then loses the war.........


I think that is the story of Yamaha engineering and pods.

 

Again, I'm not arguing that pods offer a performance gain. Nor are they a bolt on procedure, you'll most likely have to shim your needle, rejet, and practice patience. Even then, it's a stroke of luck and you best be damn sure your carbs were 100% working order, clean enough to eat off of, and it tip top shape. I ended up modifying my airbox boots to fit my pods, allowing for a more constant flow. I 100% agree with the nay-sayers that you'll lose performance. Especially in your midrange coming off the line. That's no reason to throw it in someones face every time they ask a question, or to go out of your way and create yet another "why airboxes are better than pods" post.

This page sure has changed in a negative way over the past few years from when I first joined. It's still a great resource and has great information from some great vendors and members. Chacal - I agree with a good preface to novice members who think its an easy performance gain for a quick swap, but a preface is that.. a preface.. such as: "Don't expect to gain performance from pods, and prepare yourself for an uphill battle but (insert actual helpful information)"

We rarely see this around here anymore, I can assure you all the lore made me second guess going to pods... but then i remembered this was my project bike and if i wanted real performance I'd ride my Raider, and not a 30+ year old XJ. I knew it was what I wanted and I'd give it a go -- Low and behold my bike runs! I have plenty of "extra" power to get out of the way of traffic, cross an intersection quickly, and stay with the flow of traffic. It still rides like a scaled beast when I want too as well. I'm in no means a pod expert, but if doing what you couldn't do qualifies me as one that so be it.

All in all I have pods, they work, and they work well enough that the bike is still "Fun" to ride! Is that not the goal? No matter how you slice it, what you ride, its about the ride. Pods can work on CV carbs, regardless of what people say.

Then again, if it wasn't for all you saying it couldn't be done, i probably wouldn't have bothered. So thanks for all the negative over the years, you are the true motivators!

 

Couldn't have said it better. Thank you.

And no one is claiming to be a pod expert. some of use are just trying to find a solution to a problem.

E.g people don't like wind in their face so they buy a god awful wind screen. It slows the bike down, loses performance gains. You don't see us shouting or saying if you don't like rocks in your teeth or wind in your face then buy a damn car or Yamaha made the bike and fine tuned the aerodynamics to fall into the slip stream and reach mach 5. What you are doing is blasphemous!

Honestly, if we all cared so much about performance we wouldn't be buying old jap bikes from the 80's that cost $500 - $1500.

I love my bike. Not cause of the way it looks when i bought it, because of all the hard work i put into it. Lets be honest, a stock 82 maxim with those awful bull horn handle bars are ugly as F. take away the handle bars and it starts to look sexy.

 

Ok So I stirred up a controversy , not my intent , no matter how it is phrased those that love pods will not be swayed, those that run stock airbox will not rip it out to put pods on . Okay with that out of the way if one want to run pods great , but you had better build a bracket to support the carbs , relying on the boots to support the weight of the carbs by themselves is asking a lot of the boots, realize you MAY have to pull carbs multiple times to change jets( hard on the rubber boots). You may buy a jet kit making it easier to find a good "compromise" jet set up. Face it many have posted on here asking for help , most folks try to help , but if you do not get the answer you want to hear , please do not start a tirade about it, IF I offended ANYONE I apologize .

 

Bah! Everyone is always offended by everything. If people didn't like being offended so much, I wouldn't have so many likes.