Topic: idling with no air box or pods

[laser145]

I'm about to launch into the 750K6 that I picked up. The PO was using the UNI pods with the chrome ends on them. The foam is all rotted though and the pods are removed leaving the carbs exposed (I have no stock airbox).

The carbs looked clean so I checked the oil and kicked her over a few times... then hit the starter with a fresh battery. She started, but ran very rough and died after about a min.

I assume the bike is jetted for those pods, but will having the pods off be enough to cause it to run rough, or would it start and run ok with them off?

[wannabridin]

usually it wiill run ok with just the carbs, but the air will be very turbulent going in when you crack open the throttle.  lots of racers run velocity stacks with great results.  but the stacks are designed to smooth out the incoming air charge so they run better.  you need some sort of filtration media to "smooth" out the airflow and to keep debris from coming in.  don't try to tun anything until you have the air inlet system set up the way you're going to run it.  the stock airbox is the best option for "easy" tuning.  pods look awesome, can some have had nightmarish experiences tuning them properly!  especially if you live in a windy area!!

[laser145]

I would like to return to the stock airbox...but I'll have to buy one. Mostly I was just wondering if it was running poorly only b/c of the missing filters, and if I should replace them before looking for another cause for the poor running.

[wannabridin]

like i said, get your air intake setup the way you want to run it, then turn from there.  same goes for any other motor mods.  you can't properly tune the bike for what you want it to run like later, until you have the parts on now. 

[laser145]

Thanks

I've got it running now with the carbs open. One more question, Do I have to stick with the UNI pods, or could I buy K&N's without rejetting?

Are they interchangeable as far as the jets are concerned?

Thanks

[Bodi]

They should be interchangeable. Both offer pretty good filtration and very little "velocity stack" effect but the intake air is a bit stabilized compared to open throat.
The usual tuning issue is a flat spot or hesitation in throttle pickup at low to mid throttle.

[laser145]

They should be interchangeable. Both offer pretty good filtration and very little "velocity stack" effect but the intake air is a bit stabilized compared to open throat.
The usual tuning issue is a flat spot or hesitation in throttle pickup at low to mid throttle.

I've never owned a bike without the stock configuration(and I'm not really interested in starting now) and I think I noticed that flat spot on my first ride today.  There was a moment of serious hesitation while accelerating in 2nd gear...

[ironbutter]

I have an airbox for your bike if you are interested.

[laser145]

I wouldn't assume that the bike was jetted for anything.

Good call... we'll see how it runs over the next week.

[Gonzowerke]

The bike will run like crap with open carbs, no pods or no velocity stacks like in the stock airbox on. I have read that the stock airbox flows quite good actually.

[laser145]

The bike will run like crap with open carbs, no pods or no velocity stacks like in the stock airbox on. I have read that the stock airbox flows quite good actually.

The pods don't really restrict much airflow though, right? They simply filter the air from dust...

[Gonzowerke]

The bike will run like crap with open carbs, no pods or no velocity stacks like in the stock airbox on. I have read that the stock airbox flows quite good actually.

The pods don't really restrict much airflow though, right? They simply filter the air from dust...

Pretty much. They also smooth out the airflow slightly(any filter element does)

[laser145]

The bike will run like crap with open carbs, no pods or no velocity stacks like in the stock airbox on. I have read that the stock airbox flows quite good actually.

The pods don't really restrict much airflow though, right? They simply filter the air from dust...

Pretty much. They also smooth out the airflow slightly(any filter element does)

That might be all I need, I'll know in a week.

[TwoTired]

The bike will run like crap with open carbs, no pods or no velocity stacks like in the stock airbox on. I have read that the stock airbox flows quite good actually.

The pods don't really restrict much airflow though, right? They simply filter the air from dust...

Pretty much. They also smooth out the airflow slightly(any filter element does)

Using what science or aerodynamic principle?

Any obstruction to airflow causes turbulence as it requires air to deflect from its current path.  This includes ALL filter fibers/media.
It is only in artistic renderings that the airflow is "smoothed" by filter media.

Pods put all that turbulence right at the mouth of the carbs.

Here is an illustrative picture.

[Retro Rocket]

Grabs popcorn and tunes in....

Mick

[wannabridin]

i understand the turbulence at the throat with pods dilemma, but compared to an open throat, a pod or other individual media at the throat opening will allow the carb to pull from a "pool" of air inside the filter that is unaffected by the outside environment.  this is why pods suck in crosswinds, the wind will push the less turbulent air out of the carb and make it difficult for the carb to pull in smooth air.  an airbox quells all of the airflow dilemmas associated with pods.  it allos all 4 carbs to pull from the same, smooth pool of air and enter the throats in a more laminar fashion, and is unaffected by crosswinds or other environmental factors.

[VigCS]

The bike will run like crap with open carbs, no pods or no velocity stacks like in the stock airbox on. I have read that the stock airbox flows quite good actually.

The pods don't really restrict much airflow though, right? They simply filter the air from dust...

Pretty much. They also smooth out the airflow slightly(any filter element does)

Using what science or aerodynamic principle?

Any obstruction to airflow causes turbulence as it requires air to deflect from its current path.  This includes ALL filter fibers/media.
It is only in artistic renderings that the airflow is "smoothed" by filter media.

Pods put all that turbulence right at the mouth of the carbs.

Here is an illustrative picture.

*Tunes in to this thread*.  I'm debating putting my airbox back on too from my pods.

Am I correct in assuming Re in the picture's subtitles is the Reynold's number  (laminar vs. turbulent flow)?  Neat info .