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Pod filters and the rain
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650rider
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PostPosted: September 5, 2006, 11:38 pm    Post subject: Pod filters and the rain

Hi Folks,
Got a question before I go messing things up on my bike. Pod Filters:

ikesxs is out of stock on K&N pod filters - the ones that fit behind the side covers. Anybody know where to get some?

Also - How do these bad boys work in the rain? I mean if I get hit with a big downpour here in the mountains and I'm out riding I really don't want to get crapped out on the side of the road sucking waters like a big fish. What do ya think? I almost did a set last year but give the pods I had to a buddy of mine for his bike - but can't reach him to talk about it.

Is it worth changing the filters and rejetting? I just hate all the airbox junk, I'm sure it's an "Engineering Masterpice" I just think it bulky and messy looking.

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650chopper
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PostPosted: September 6, 2006, 7:41 pm    Post subject: Re: Pod filters and the rain

You can find the pods on ebay. You just have to know what size your carbs are. I havent tried them yet but i am going to
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650rider
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PostPosted: September 6, 2006, 9:05 pm    Post subject: Re: Pod filters and the rain

Thanks I saw some on ebay bu they are round-tapper the ones mike had are more oval-tapper and fit behind the side covers.

And I'm really wondering about running in the rain issues.
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ajohnson
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PostPosted: September 7, 2006, 11:03 pm    Post subject: Re: Pod filters and the rain

those filters and many other similar filters from other companies should be available for order at any bike shop, even those that aren't dealers (which will probably be your best bet). Out here in the west at least, there are several catalogs of motorbike parts that you can order from and get parts in a few days at most. I just ordered 4 pod filters for my KZ650 from Parts Unlimited for about $50. They are not K&N, and will probably not let as much air through, but hey that might just mean i won't have to rejet. This was the case with my last bike, a gs450, no need to rejet with UNI filters.
If you insist on K&N, the Parts Unlimited catalog has round, oval, tapered, angled K&N filters in various sizes. No doubt wherever you are there is a similar company around.

I totally agree by the way about the airbox. what a crappy way to design something. I've been told by some freinds who went to MMI that they do indeed create better performance, but they complicate things so much when it comes to working on or being able to see the carbs, battery, motor, and etcetera that I just can't see it being worth it. Plus with pods you can check the condition of your filter every time you ride, and can therefore recognize a dirty air filter much sooner than if it's stuffed inside a box.
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650rider
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PostPosted: September 7, 2006, 11:32 pm    Post subject: Re: Pod filters and the rain

Ajohnson,
Thanks for the reply - how do your pods on the KZ work in the rian? Ever have a time you had to ride in a good downpour?
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Buzz
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PostPosted: September 8, 2006, 8:14 am    Post subject: Re: Pod filters and the rain

Mike has the 53mm and has back ordered th 52mm.
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5twins
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PostPosted: September 8, 2006, 9:55 am    Post subject: Re: Pod filters and the rain

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Last edited by 5twins on September 11, 2009, 4:36 pm; edited 1 time in total
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650rider
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PostPosted: September 8, 2006, 11:11 am    Post subject: Re: Pod filters and the rain

I think I'm going with the K&N's that fit under the side cover. Thanks to you all for the input and thanks to 5twins for the link for the product and rian info
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650rider
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PostPosted: September 8, 2006, 11:13 am    Post subject: Re: Pod filters and the rain

Hey by the way what is the MM of the carb for a 1979-D, anybody know?
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5twins
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PostPosted: September 8, 2006, 12:53 pm    Post subject: Re: Pod filters and the rain

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Last edited by 5twins on September 11, 2009, 4:37 pm; edited 1 time in total
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650rider
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PostPosted: September 8, 2006, 1:27 pm    Post subject: Re: Pod filters and the rain

Rocking info thanks - I was having a heck of a time trying to get a messurement on the OD of the carb where the filter mounts.
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royfisk
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PostPosted: September 9, 2006, 4:41 pm    Post subject: Re: Pod filters and the rain

Just to bring it to attention the reason for the heavy ugly pain in the xxx air box has absolutely nothing to do with performance, Its all emissions guys not performance, If it were we wouldnt be changeing them. Just you know???
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ajohnson
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PostPosted: September 9, 2006, 10:17 pm    Post subject: Re: Pod filters and the rain

I live in the high desert, with only a few inches of rain a year, though there is plenty of snow, so i can safely say that I have had no problems with the filters in a heavy downpour. Laughing

I would be inclined to agree about the performance issue, but I figure that if a race bike has an airbox, and I believe that most do, there must be a benefit. Also, airbox's have been used since the '60s at least right? Not much emission control going on then. Nonetheless, they are cumbersome and difficult, and i figure that the decrease in performance is worth the ease of maintenance.
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royfisk
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PostPosted: September 10, 2006, 6:22 am    Post subject: Re: Pod filters and the rain

ok lets think about this a second. All a internal cumbustion engine is. Is a air pump. It draws in air and gas, cumbusts it and then exhausts it. The more air you flow the more power you produce. In other words A engine with a restricted intake has to draw harder to suck in as much air as one with a open air intake. This therory is supported by todays technology of superchargers and turbo chargers. Also look at suzukis last hurah with the gsxr carburated models. In order to get the bikes maximum power at the top of the rpm range the used a ram air system to pressureize the air box. You can actually feel this thing work. The engine did not benefit from the scrad untill about 100 miles per hour. So in the lower gears there was a slight rich condition going on . Dyno tunning cured this but then there was a slight leaning condition going on in the higher gears. As for the 60's no most bikes did not have air boxes. Most brittish bikes had Round air filters right on the carburators, like we do with our pods. Early model xs 650s had simular oval filters that were connected together with a hose. Harley davidson had round air filters also. bmw had a box on some models and simular filters as the rest of the world. As for emisions they came into play beleive it or not in 1971. However it was not very sufisticated and only required that engine breathing not be discharged into the atmosphere. This is when air boxes started. Air boxes have a benefit to manufactureing It helps buy restricting down air to maintain a constant gas mixture therefore keeping the engine in its 14,6 optimum air fuel mixture. As for performance however it is restrictive, just as the heads are restrictive, and the exhaust. Performance minded people dont care that the air fuel mixture goes slightly up and down as you throttle up and down only the epa does. Most bikes do not run correctly without rejetting after airbox removal. I learned this 20 years ago when tunning a gs-750 I had cleaned the carburators and installed them, the bike would not start. I removed the carbs again and went through them again still would not dtart. did this 3 times. I was getting mad at this point somehow I managed to through a rag on top of the air box " over the round filter cover" totally by accident. Then when I pushed the starter button it fired up instantly. I removed the rag and she died. I put the lid back on and the bike ran good. Anyhow enough schooling for now, ajohnson is correct about modern race bikes having a air box, It is because of one of 2 reasons #1 most modern bikes are controled by a computer and and it wouldnt be cost affective to alter it. #2 most modern racing rules requires production motorcycles. Go look at vintage bikes and let me know how many air boxes are there.
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Jack
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PostPosted: September 10, 2006, 8:07 am    Post subject: Re: Pod filters and the rain

Air boxes regardless of their weight and engineered uglyness do in some degree have a direct impact on overall performance particularly in the low to mid range power band where low and mid range torque is mostly useful in coming out of the turns. I admit the Xs air box is one ugly piece of scrap metal but it's design does effectively increase the air speed as it the air enters the inlet bell mouth and with the increased air speed and the inner reduction design of the air box,including the balance tube which offers an increase in the area of volume to draw more air in during the intake cycle does become some what pressurized.
But i have to admit, open indepentant filters on the XS adds new charactor ,so rip off the air box guys Laughing
I tried on several occasion on my BMW R/90S to eliminate the stock air box with extented air tubes with KN filters with intensions of drawing in a more dense air mixture for the combustion process but all my efforts drastically reduced bottom end perfromance BIG TIME.The Germans are the worlds most elite engineers and the boxer engine is a well thought out engineering marvel and to think i could out smart them in making improvements.HAHA! Laughing ................Jack
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650rider
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PostPosted: September 10, 2006, 9:48 am    Post subject: Re: Pod filters and the rain

I have my answer. I'll try the pods and rejet project but I'll keep the box just in case the project does not woork well I can always go back!
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ajohnson
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PostPosted: September 12, 2006, 10:34 pm    Post subject: Re: Pod filters and the rain

It's obvious that the more air you can get in the better off you are (so long as the fuel comes with it). The question is whether it's easier to get air through the filter when that air is rushing by at 60mph or when the air is sitting more still in a pocket at the intake of the carbs. When it is properly explained, as by Jack, it makes perfect sense that it is easier for air to get in the carbs if there is a pocket of positive pressure for them to feed off of, rather than having to draw it out of the open (neutral pressure) air that is also moving in the opposite direction.

Perhaps this is something that people may always have to agree to disagree about, but at least we can all agree that the boxes are lame.
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650rider
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PostPosted: September 12, 2006, 11:35 pm    Post subject: Re: Pod filters and the rain

Now that's a rocking comment ajohson - in fact I have been working on a little "Scoope" that clips to the end cap of the K&N filter ( don't have a filter yet I'm working from a end cap I found) that catches air and well scoopes it to the filter from the outsides of the filter pod. I'll poat a photo when I get them done.
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ajohnson
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PostPosted: September 13, 2006, 4:23 pm    Post subject: Re: Pod filters and the rain

This is something that I have been contemplating too. I wonder if a device could be engineered to fit on the end of a pod that would turn the air flowing by the other direction into positive pressure flowing toward the carbs (like water flowing upriver behind a rock). i would be really interested to see how your scoops work.
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5twins
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PostPosted: September 13, 2006, 6:06 pm    Post subject: Re: Pod filters and the rain

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Last edited by 5twins on September 11, 2009, 5:06 pm; edited 1 time in total
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650rider
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PostPosted: September 15, 2006, 10:52 am    Post subject: Re: Pod filters and the rain

ajohnson wrote:
like water flowing upriver behind a rock.

Thats excatly what I'm talking about - BANG!

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royfisk
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PostPosted: September 15, 2006, 3:23 pm    Post subject: Re: Pod filters and the rain

I have seen on the dino results from the pod filters verses the air box good power gains thruout the power band . Now as for the air rushing by and creating a lack of aitr for the intake to keep up with, I dont think that 60 mph is fast enough to create this situation. 100 maybe but not 60. If we all stop and look at our brittish cousins every triumph, bsa, and norton I can remember from the 60's did not use air boxes. They had round paper element clamp on filters with a chrome trim ring around them. These bikes run good for what they were. Also what about suzukis scrad system, this was to pressureize the air box, The guys at the track tell me the system is useless on all but the larger tracks because there is very little pressureizeing going on untill around 100 mph. Iknow of a couple riders at the loudon track that dont even bother useing them. But this is another one of those subjects that everyone has a theory. My theory will be done on the dino where the results can be recorded. If your bike has been tuned on the dino I dont beleive that most of us would see alot of intake problems with the pods. But we would be certain that our bikes are running to its potential. Once my exhaust is finished and my topend work, with the cam I will use I will have it tuned both ways and post the runs, nope cant do that I'm running vm carbs. I will get a comparisson runs with another bike that will be coming in this winter.
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paulson_shawn
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PostPosted: June 28, 2007, 12:40 am    Post subject: Re: Pod filters and the rain

if they didn't increase airflow y would re-jetting b necessary ?
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