DIY Pod Filters

[scotch]

So the selection of pod filters for the cb500/550 is limited.

K&N makes a set, but they cost around $200
http://www.knfilters.com/search/product.aspx?prod=rc-0844

When i took a look at their specs, they were 3"O.D. with a 2" height.

Fortunate for the cb500/550 the size of the flange needed to fit the O.D. of the carbs is 39mm, which works out to be 1.53". As it turns out, a piece of flexible rubber hose with an I.D. of 1.5" fits on the carbs snugly.

With all this in mind, i figured it would be simple enough to make my own pod filters using K&N's dimensions.

First thing i had to find was a container with a 3" diameter. I had an idea to use a jar for holding bulk spices but i couldn't find anything the right size. I took a trip to a craft store and they had candles in metal tins that were exactly 3".

So i picked up 8 of these for $6. The paisley print alone must add 2hp?

Next i had to find an air filter with a total height equal to or less than 2". Spent a bit of time at the auto parts store and found this.

I picked up 2 for $10, and at the same time grabbed a pair of tin snips for $20.

With a little bit of math and a few bloody fingers, i made my self a ring of filter material.

While cutting i was sure to leave some extra filter material on the inside and some metal on the outside so the materials could overlap and make as good a seal as possible. The overall length of the filter material was 9". I cut it at 10" to leave my self some room to bevel the edge and overlap the filter and metal screen.

I marked the other part of the candle tin and trimmed it down to the same shoulder height as the lid.

And with that i've got my self a pod filter.

So with a total of $36 invested i'm well on my way to having a set of pod filters.

I've still got to make 3 more and drill my holes for the manifolds to the carbs, as well as fasten the filter material to the container. I'm not sure if i'm going to glue it in or put some kind of bolt from one of the ends to the other so i can swap out the filter material without having to make a whole new set.

 

[DesmoBro]

Z1 has the Emgo filters (not recommended) there cheap tho like you could have a set of 4 for $40 and they come with clamps too but there chrome the paisley may be the look your after I don't kno....But if you must frankensteinery is always a fun option Just don't Glue them to the carbs whatever you do .....Live, Learn, Then put the stock air box back on.....

 

[scotch]

Villagers hats was my initial plan, but this was a close second. I understand that the paper filters will clog with minimal use. This is more of a proof of concept. If it works well enough i may find some closeout K&N filters and chop those up. If it all works shitty, at least i didn't spend a ton of money. I haven't sealed the paper yet. It's just sitting in place until i figure out how i'm going to get everything sealed up. Any suggestions? The way that the air filter i chopped up was made just had the layers overlapped and trapped between the inner and outer mesh layers.

I bought a set of the emgo filters too, but they are too tall and contact the frame.

I'm running the stock airbox and it's just a real bear to deal with when changing jetting or doing anything that requires the carbs to come off the bike.

 

[DesmoBro]

Try using a hot glue gun to attach everything ur making the pod out of....You may be able to shorten the Emgo's with little effort and get them to fit....What kind of bike are you working on? There may be someone on here who has already done this and knows a good sized jet to run

 

[MotoMadness]

$48 for all four filters

http://moto-madness.com/catalog/index.php?main_page=product_info&cPath=342_770&products_id=1377

 

[scotch]

I'm mounting them on a cb550.

Again, the emgo filters at 3 1/4" are far too tall. They do make shorty versions that will fit, but waiting 4 weeks to get them here sucks.

Swivel, if you like these, you should have seen my home made condoms. Those things were a masterpeice.

 

[DesmoBro]

the ones motomadness posted should work

 

[scotch]

I'm not sure where the 3 1/4" measurement is taken from on the site that motomadness posted, but my emgo's measure 3 1/4" in full height (rubber flange to the small tapered end).

If i wanted to buy a set that fits, the ones that do are well documented on the SOHC4 forum http://forums.sohc4.net/index.php?topic=29437.0

This is a last ditch effort for me in the realm of pod filters. After shelling out the money and waiting for them to arrive i'm frustrated. If i'm going to spend more money on air intake, i'm going to get in touch with they guys at Steel Dragon and buy a set of velocity stacks that were designed to fit the 550.

 

[DesmoBro]

velocity stacks are cool and all but usually people upgrade the exhaust add pods before they mess with the carbs....it's one of those things where once you start you don't stop check out the Open pipes video in the 1-800-cafe-help section it shows you what problems your likely to run into

 

[DirtbagUT]

I like the idea! I need to figure out what k and n pod filter will fit my cb125 carb :-\

 

[scotch]

I'm very familiar with jetting. I've already got a 4-1 on the bike and i've had to adjust the carbs to accomodate that. I just had a set of carbs bored out by Rick Denoon http://www.dotheton.com/forum/index.php?topic=32327.0.

I'm getting them dialed in now with the stock air box then i'm going to run a few tests with some different intakes. This DIY pod filter is just an idea to help me get some more data.

I'm also considering cutting down my existing filters and re-gluing the small tapered end on to make the overall height fit. We'll see how that turns out too.

Dirtbag - if you measure the outside diameter of the carb on your bike it'll give you an idea of what size filter you should need. There should be a soft rubber manifold that connects the stock air box to the carb. Slide that back and take your measurement from there. Be prepared to re-jet. This is a good starting point for jet sizes http://forums.sohc4.net/index.php?topic=58112.0. Keep in mind that it's a lot of guess and test work to get working properly.

 

[ktriple]

Ive seen angled uni filters work, and there's no reason the green "sock"style filters shouldnt either. Plus you lose the metal end cap with these, which can make tuning difficult/impossible.

 

[stmizner]

Scotch, this is a great idea. I like that it can be adapted to make rectangular double filter sets from tea tins and that it uses a good deal of ingenuity. Well done. I would seal them with window weld urethane caulk.

 

[ponieswhee]

I did a similar DIY deal on my stamped frame CB175. Ended up using some scrap furnace duct aluminum and bent it into an airbox shape. The filter is a dirtbike foam filter cut to shape and sealed with hot glue and caulk. It works a ton better than the old clogged individual airboxes and doesn't stick out at a funny angle like you have to do with pods on stamped frame CBs.