POD filter question

[88kat-rider]

I have read countless threads about the K&N pod filters and how terrible they are. or i should say how terrible they make the bike run.

I bought my old beat up 88 Kat 600 and it was missing some parts. Specifically one side of the exhaust and the air box was also gone. I have ordered and waiting for the arrival of my new vance and hines 4-1 pipe and header. I thought I could solve the missing air box issue by putting on the pod filters on each carb. I have them ordered aswell.....before i found out how much trouble they are...

I wanted to know why people have such problems. I assume most people that put them on have 1.) stock exhaust, and 2.) also don't realize its changing the amount of air that flows through the filter (400 cfm more) which changes the air/fuel ratio. These bikes being carburated don't self adjust like a fuel injected bike would so they run like bags.

Also what do you do with the one hose that goes into the airbox??? with no air box are you plugging it? putting a breather filter on? I believe its a PCV so should be good with a breather filter on it.

Does anyone run the carb filters and like them? what did you have to do to make it run nice?

[05RedKat600]

CV carbs don't run good with pod filters. Slide carbs do. CV carbs don't. You can't equalize the vacuum on the 4 carbs thus each carb is out of sync with the others. If you don't know how to tune a bike, you will spend a lot of time on a dyno or in a shop to make it run right. You will also need a Factory Pro stage 3 jet kit, and lots and lots of time and knowledge.

If you had read everything you said you did, you would have this answer. You just want it validated for you since you already spent the money.

[88kat-rider]

well if you read the beginning of my thread you would realize I know how to tune a bike, lots of experience with Mikuni carbs specifically.

I very much understand why they aren't working on peoples katanas (or should say working like crap). Like i said before its obvious the air/fuel mixture has gone outta whack due to the increased flow from the K&N. No computer to control this value as they are not fuel injected so it must be done manually.

I know it will take a lot of fiddling with to get it right and I might just pull the remaining hair out of my head doing it but it will be done. My last project is a riding lawnmower with an air cooled snomobile engine running it that I race on oval ice track...and its turbocharged...pretty sure this is a piece of cake in comparison.

I have never tried the pod filters on a motorcycle (lots of snowmobiles) and no.... I didn't read up on the troubles they caused on katana's specifically as i never had any issues with them before. I know some people on this forum run the pods and was looking for their input. Specifically what mods have been done (carbjet, exhaust..etc)

I have read so many threads on this topic so don't even go there and tell me i didn't read them...all anyone does is ***** about the questions being asked.
Don't answer them if you don't like it plain and simple.
I haven't received my filters yet so I cant tell you my experience with them yet. I will post what I did to make my kat run good with them in the future.

[HemiKat]

Basically 99% of the people on this site just recite what they hear from others. 99% of those people have never tried Pod filters. Many of the people on here have had pod filters with bad results and believe a lot of that has do to with other issues that arent related to the filters. Granted many capable people on here have run Pods and dont care for them.

Theoretically CV carbs need a constant pressure to allow the slides to open properly and the airbox helps regulate that. More consistancy makes the bike more predictable and more easily tuneable. With the amount of airflow and the area of the air intake pod filters have they dont allow the vacuum levels to be consistant. I believe there are only a handful of people on this site capable of tuning a bike for K&N's and mostly all of them dont think it is worth the hassle. I run K&N's for the shear fact that people say it cant be done. Was it difficult to dial in? Yes, it was more difficult that typical stock set-up, but my bike is far from stock. I had them on my 750 and they ran great, so I kept them with my B12 (running the 750 carbs).

Are Pod filters worth it? Not to a lot of people? But for those that say they cause running issues and will never be perfectly tuned, you are more than welcome to ride my bike, which has no throttle issues, flat spots and makes 119rwhp.

But im sure 20 more people will chime in saying how its impossible, and its all he said she said.

[88kat-rider]

Thanks for the input.

I know it wont be easy, and i am doing it because I never got an airbox with my 88 600F.

My plan is and has always been for this bike to replace the stock exhaust with a new vance and hines setup because i am missing one side of the exhaust. Throw on the pods, jet the carbs and have them balanced.

I know of some bikes that use CV carbs and don't need to be jetted to run the pods. they just run nice with them.. obviously katanas aren't one of them.

I have a friend that has a 93 kat 600 with the pods and is in the process of making it run nice. he bought it like that...no airbox 2 double pod filters. It seems very sluggish over 4000rpm and when you romp on it the intake sounds like a vtech honda engine when you romp on it. really noisy!

It has shown some improvement, the bike wouldn't idle before and would die if you tried to give it a good rev once you kept it going. It has stopped doing all that.... it idles smooth, revs nice, but still sluggish over 4000rpm. Probably will jet his carbs this weekend.

[05RedKat600]

well if you read the beginning of my thread you would realize I know how to tune a bike, lots of experience with Mikuni carbs specifically.

I very much understand why they aren't working on peoples katanas (or should say working like crap). Like i said before its obvious the air/fuel mixture has gone outta whack due to the increased flow from the K&N. No computer to control this value as they are not fuel injected so it must be done manually.

I know it will take a lot of fiddling with to get it right and I might just pull the remaining hair out of my head doing it but it will be done. My last project is a riding lawnmower with an air cooled snomobile engine running it that I race on oval ice track...and its turbocharged...pretty sure this is a piece of cake in comparison.

I have never tried the pod filters on a motorcycle (lots of snowmobiles) and no.... I didn't read up on the troubles they caused on katana's specifically as i never had any issues with them before. I know some people on this forum run the pods and was looking for their input. Specifically what mods have been done (carbjet, exhaust..etc)

I have read so many threads on this topic so don't even go there and tell me i didn't read them...all anyone does is ***** about the questions being asked.
Don't answer them if you don't like it plain and simple.
I haven't received my filters yet so I cant tell you my experience with them yet. I will post what I did to make my kat run good with them in the future.

I told you what you need to make it work with the Kat. You really should at least listen to that part. Factory Pro Stage 3 jet kit. Get one. I never said it wouldn't work, I said it wouldn't work well. Don't reply to posts if you don't like them, even though I told you how to make it work. You're welcome.

[88kat-rider]

I told you what you need to make it work with the Kat. You really should at least listen to that part. Factory Pro Stage 3 jet kit. Get one. I never said it wouldn't work, I said it wouldn't work well. Don't reply to posts if you don't like them, even though I told you how to make it work. You're welcome.

I did listen, I already said I would be jetting the carbs.

Thanks for telling me what I will need but, I can tell from your answer your not running the pods on the carbs. I don't know if you have ever tried it, or just repeating what others say. I don't know if you even know what your talking about. You might, but also might not...no offense intended


Either way i have read all the "bad" about the pod filters and was looking for some of the positive responses, regardless of how few and far between they are


I wanted someone who runs the pods to tell me what mods they have done to their bike and how they achieved the result

I have also just purchased a factory airbox and filter to use as a baseline. I will attempt to reproduce the conditions the factory airbox creates without using it. (gotta love working in a fuel shop )

If all else fails and i run outta hair to pull out over it, I will at least be a bald guy driving a kat that runs.

[mike1346]

I bought my 96 Kat in 2000 and it already had the K&N Pod filters (1 filter covering 2 carbs, so I have 2 pods not individual pods per carb) to my understanding the stage 3 jet kit was installed, Vance & hines pipe and timing advancer. Before I parked it for 3 yrs I ran only 93 Octane and never had an issue. I recently got it going again and put 87 octane in it, it runs good but not as smooth. It could be the crap ethanol 87 octane or maybe my carbs are still a little dirty, either way I'm putting 93 back in to see if that will straighten it out. The point I was making is I never had a issue with mine using 93 octane with the above mods, maybe I'm one of the lucky few? Good luck to ya.

[cintidude04]

It ran smoother with 93 because you needed to richen up your fuel mixture a bit.
And for the OP, mine aren't K&N pods but they are pods. You will need Dynojet Stage 3, I suggest a full exhaust. And with my 89 GSXR750 cams it is a little easier to tune. But the best set up for pods would be to find you a used set of RS34 Flatside carbuerators.
Hope that is of some help

[rubbermounted]

Sorry for the large posting but its the only way to explain what you are asking....
This is not my opinion it was lifted from another forum yet its the method I used....


MAIN FUEL JET SIZE CHANGES NEEDED PER TYPICAL MODIFICATION:

Typical Exhaust Changes:

+2 main fuel jet size for custom 4-into-2 exhaust
or
+4 main fuel jet sizes for 4-into-1 exhaust
or
+4 main jet sizes for no muffler (open headers)


Typical Intake Changes:
+2 main fuel jet sizes for single K&N filter (inside a stock airbox)
or
+2 main fuel jet size for drilling holes in the airbox with stock filter
or
+4 main fuel jet sizes for individual pod filters (no airbox)

Additional changes:
- Add up all the main fuel jet size increases and subtract 2 sizes.
- Decrease main fuel jet size by 2 sizes per every 2000' above sea level.
- Under a mis-match condition, such as when using pod filters with a 100% stock exhaust, or 4-into-1 header with stock filter and air box, then subtract 2 main fuel jet sizes.

PILOT FUEL JET SIZES CHANGES NEEDED PER TYPICAL MODIFICATION:

Pilot fuel jet size changes are related only to the change in main fuel jet sizes according to the main fuel jet size formula described above. Note that this pilot fuel jet rule is for the main fuel jet size change BEFORE any main fuel jet altitude compensation is factored in:

Increase the pilot fuel jet size +1 for every +3 main fuel jet size increases.

Additional changes:

- Decrease pilot fuel jet size by 1 for every 6000' above sea level.

PRECAUTIONS:

- Make sure your carbs are in perfect working order before making jet changes....meaning fully cleaned internally and rebuilt, operating properly in their stock configuration, proper sized air jets and needles, etc. Otherwise, you'll like find that all of your efforts are going to be a HUGE waste of time.

- Check plug color often and adjust as needed, 2 main fuel jet sizes at a time and 1 pilot fuel jet size at a time. Bright white plug insulators are a sign of an overly lean fuel mixture condition and WILL cause damage to your engine over time, up to and including engine seizure!

- Synch the carbs after each jet change.

- Make sure the floats are set correctly

- Seriously consider purchasing a Colortune Plug Tuning kit.

- You may find it necessary to make changes to the size or shimming of the main jet needle. There are no guidelines on what or how to do these changes, this is true trial-and-error tuning!


EXAMPLE:

A 1982 XJ550RJ Seca using an aftermarket Supertrapp 4-into-1 exhaust and a single K&N air filter in the stock, unmodified airbox. Bike is primarily operated at an altitude of 2600 feet above sea level.

XJ550 Seca Stock Mikuni BS28-series Carb Jetting:

#112.5 Main Fuel Jet
#35 Pilot Fuel Jet
#70 Main Air Jet
#170 Pilot Air Jet
4GZ11 Needle


MAIN FUEL JET SIZE CALCULATIONS:

Changes made:

Exhaust:
4 into 1 with Supertrapp = +4 Sizes Main Fuel Jet

Intake:
K&N Pod Filters = +4 sizes Main Fuel Jet
----------------------------
Equals: +8 main fuel jet sizes above baseline
Subtract: -2 main fuel jet size per formula above
----------------------------
Equals: +6 main fuel jet sizes due to modifications, thus:

Stock main fuel jet size is: #112.5
+ 6 additional sizes
= a #118.5 main fuel jet size
---------------------------
Subtract: -2 main fuel jet sizes for Altitude of 2500' Average

= #118.5 calculated from above
-2 jet sizes for altitude adjustment

= a #116.5 main fuel jet size.


PILOT FUEL JET SIZE CALCULATIONS:

The formula is: +1 pilot jet size increase for every +3 main jet sizes increased.

Stock pilot fuel jet size is: #35
+ 2 additional jet sizes (since we went up +6 main fuel jet sizes before the altitude compensation was factored in):

= a #37 pilot fuel jet size.

Note that no altitude compensation is needed on the pilot fuel jet since our elevation is less than 6000' a-s-l.


------------------------------

RESULT:

A #116.5 Main Fuel Jet and #37 Pilot Fuel Jet is A GOOD STARTING POINT.



Sorry forgot to mention your carbs if you dont already have the specs...



Katana (GSX600F)

1988-89 (US Models)

Type: BST31SS

Main Jet
Cylinders #1 and #4: 137.5
Cylinders #2 and #3: 135

Main Air Jet: 1.0mm

Jet Needle
California: 4CZ-5-1
Expect California: 4CZ-4-1

Needle Jet: P-8

Pilot Jet
California: 37.5
Except California: 32.5

Pilot Air Jet
California: 155
Except California: 150

Pilot Screw setting: Preset

Starter Jet (choke): 45

Float Height: 14.6mm (+/- 1mm)


1988-89 (UK Models)

Type: BST31SS

Main Jet
Cylinders #1 and #4: 137.5
Cylinders #2 and #3: 135

Main Air Jet: 1.0mm

Jet Needle: 4CZ-3-3

Needle Jet: P-9

Pilot Jet: 40

Pilot Air Jet: 160

Pilot Screw setting
1988: 1-7/8 turns out
1989: Preset

Starter Jet (choke): 45

Float Height: 14.6mm (+/- 1mm)

(hope this puts me in the 1% catagory)

[TRPUT]

Nice work!

If I apply those equations to my bike:

+2 for K&N in Airbox
+4 for aftermarket exhaust
-4 after fitting bung to exhaust
-2 (apparently for the hell of it!! )

= 0 carb mods as a starting point ... which tragically after weeks of mucking around is where I ended up! And it seems to work!

[loudnlow7484]

well if you read the beginning of my thread you would realize I know how to tune a bike, lots of experience with Mikuni carbs specifically.

If you are great at tuning Mikuni carbs, then why are you asking questions here?

As I've said before, it certainly is possible to get them to work, but getting them to work on an otherwise stockish Katana is going to require more work than it is worth, and work beyond what most home mechanics (and many pro mechanics) are capable of.

I had pods on my CV's. They worked pretty well with the GSXR cams and a full exhaust, and many weeks worth of tinkering. I'd say I probably spent 30-40 hours total getting them set up as close as I could without a dyno. If I paid myself just $10 per hour for my labor, I could have bought a set of used RS's (or what a local shop would charge to stick it on the dyno/sniffer for a few hours). I guess it depends what your time is worth, though.

And in the end..... I now run RS36's, and they worked about 90% correctly with completely stock settings, and they are now at about 95% of dead-balls-on with just a needle-height adjustment. Plus they sound sexy and made the bike faster.

Sorry for the large posting but its the only way to explain what you are asking....
This is not my opinion it was lifted from another forum yet its the method I used....


(hope this puts me in the 1% catagory)

That method MIGHT get you a baseline to start with, but it's not going to get it exactly right.

By the way, I read countless times on that forum that it was impossible to make pods work well on an XJ650. Having set up pods on both an XJ650 and a Katana, I'd say the Katana is at least 4x harder to get them working right on. The XJ was actually really easy by comparison.

Neither of them were perfect, though. The XJ had just a little flat spot right above idle (like, 1500-1800 RPM), and on the Katana, the power ramped up more abruptly than normal between 5k RPM and 8k RPM. Both were perfectly streetable, but not dead-balls-on perfect.

[88kat-rider]

If you are great at tuning Mikuni carbs, then why are you asking questions here?

Pretty sure its the place to ask questions, no crime in that here.

why are you such prick... is my question

oh an i never said i was an expert, just that i have had alot of experience with mikuni carbs...

[thenastiestnate]

I'm with everyone else that says pods are pretty much a waste of time on CV's. I can tell you from experience on my gixxer they are very difficult to tune in the garage. I think mine are pretty close, but you can never be totally sure without dyno time. My old GSXR 750 has a set of BST38's which are already hard to tune anyway and the K&N's make tuning feel like pin the tail on the donkey.

I am still going to buy a set of unipods for one of my post 98's, but it's for play and looks. I don't expect to get any serious performance gains.

[Dark Katanain Ryder]

Wow, After spending like a month and carbs off and on about fifty times, I'm using a K&N Kit 126 main, Dual pod filters 4 into 2 into one head pipe (I don't knew the make) with a D&D canister. needle clip in center (but not sure had it up/down so many times).
Floats 14. the bike runs good, some slight Hes off idle but you throttle right thru it.
Tried a 130 jet would easy pull up the wheel, but it would foul the plugs when you chopped the throttle. Hope this helps. I have nothing else to add.