Topic: 29 smoothbore air filters Q?

[Don R]

 My K2 836 Hot Rod bike has velocity stacks on a set of 29 Mikuni's, it needs an engine top end rebuild so when it goes back together, I will want some decent filters.
  I've considered trying a Z1 or KZ1000 air box but not sure if the Z1 box would fit the 750 frame without hacking it up a bunch. As fun as my KZ1000 air box is to put back on, I'd hate to remove it just to check.
  Lacking an otherwise decent set of filters, I thought the APE filter pods would be a good substitute.  Any opinions or proven products?

  I have a set of Emgo pods, it was suggested I throw them away. They don't block the air bleeds but also don't filter much either.  Even with plastic baffles covering over half of the insides my KZ1000 didn't like them.

[seanbarney41]

I'd get the APE filters and thanks for reminding me about them!  No point in running an airbox with the smooth bores...not that you can't, but I believe their original design intent was to be able to deal with some turbulence in favor of high flow.

I had been running some Aljphabet dual breadboxes on mine when a little start up spit back caught the filter foam on fire...while parked at the gas pump!  I paniced and snatched it off the carbs and chucked it out into the street, spewing a bold streamer of thick, rancid foam smoke.  No one seemed to notice so I attempted to gather my parts back up in vain.  The cover snap wire was not to be found and the mesh was covered with molten foam.  I have not been able to find suitable size quality pod filters.  Your mention of APE has helped possibly!  Thanks

[PeWe]

I used KN oval pods on my VM29 last time.

[Don R]

 I'll search for the K&N's again, The APE filters are difficult to find on their web site but if you try a few choices they are still there. I think I got to them from the sohc section not the air filter page. 

[PeWe]

I went into the garage to check mine.
Model RC-2454
https://www.knfilters.com/rc-2454-universal-clamp-on-air-filter
Holy crap, more than double price now! Almost triple.
Bought mine 2013 on eBay UK.
Might be better price than KN site.


Dynomans filter look similar for a better price.
Might have 44mm version on the shelf.
They sold smoothbore carb boots for CB750 some years ago, so filters might be lurking there.
http://dynoman.net/carb/airfilt.html
My filters above when mounted on my VM29 carbs on my K6 before I ordered some from Yamiya making it blue and other sellers.

[scottly]

Do the APE or K&N pods work with the stacks? I've always run some sort of foam "sock" type filters over the stacks on my Webers. The latest UNI filters have an ID the same (or close enough) as the OD of the outer lip of the stack. They were too long, especially on the 1&4 carbs, but it's easy to shorten them, as well as the aluminum inner support spring that keeps them from collapsing under vacuum. A zip-tie holds them in place. They aren't exactly pretty, but they are mostly hidden under the side covers, and they work.

[PeWe]

My Mikuni TMR's have a filter adapter with stack function.
Maybe possible to make similar?
Mine have 54mm outer dia. Use K&N pods.
(Yoshimuras version of adapter has 50mm outer dia)



But your Webers are rather long. My KN filters just fit in front of the frame for 1,4.
You need a slimmer bread box type?

[scottly]

Those look like the best of both worlds, Per.

[PeWe]

Ues, they work fine now after some adjustments.

Maybe you can make something for your Webers?
You have the machinery and you are a very skilled and technical guy.....

[Don R]

   Per, that looks like it would assure balanced pressures to all four pilot jets and keep them clean.
   I also considered uni filter socks over the existing velocity stacks on ther 29's.
   
   I have to say the crumbling unipods that came on my kz worked a LOT better than the Emgo pods the shop put on it.  I ended up going back to stock on that bike's air filter system. 
 

[Don R]

 I found K&N RU2454 at Summit racing for $139.99 and $129 with my racer discount. They have a rubber end cap rather than the chrome one with the K&N logo which is just under $200. They are only oval ones I found, in this size the APE's are round.