All pods are not the same

Heres a picture of a K&N pod air filter (on the left) and an Emgo (right).
See the next post for the Rest of the story.
Daniel

When you use the Emgo pods on a C/V carb, they block some of the air passages (see picture) and this affects performance. They can be ground away to clear the passage, but the design of them often does not leave enough to keep a good seal with the carbs.
The cheapy pods usually have a removable mounting flange.
Sure the K&N are alot more expensive, but you get what you pay for.
Daniel

Post edited by: dgfischer, at: 2005/10/18 07:08

Dang Daniel... never noticed that! I have been testing with Emgo pods when I test CV carbs and now will have to get a different brand for sure.

The longish slot on the top of the intake is the VENT... if you block this guy some, throttle response will be sluggish AND you will have float issues... leaks or non-flowing gas can result.

The two smaller holes at 3 and 9 oclock feed the pilot circuit and main jet circuit (when slide is closed) and blocking them will surely affect low rpm operation.

Thanks for bringing this up! You can copy/paste the pics into a MSWord .doc file and the write up and put it into the Filebase in the non-model specific info... would be a VERY good thing to refer to in the future.

What about non CV type carbs? Is this an issue too?

Now you have me wondering if I should consider trying K&Ns. When I used the Emgo pods I never could get the jetting right. I went through several diffrent sized jets and tried about every possible position before I finally gave up, and went back to the air box.


I deleted the triple post. KZCSI

Post edited by: kzcsi, at: 2005/10/18 14:48

Good eye. Thanks. Have cone style EMGO on the GS1000. I'm kinda in the middle of tuning it and haven't gotten far enough along to notice if they're causing any problems. Will have a look and see if that cone EMGO interferes. Likely not until this weekend as I'm kinda in the middle of tiling a bathroom in the rental unit.

-Duck

savedrider wrote:

What about non CV type carbs? Is this an issue too?

Ive tried to use these cheap pods with the inner lip on two KZ650 with slide carbs and in both cases I had no end of trouble with the jetting.

Both cases suffered low speed & cold starting problems.

In one case, I could not get the jetting right and ended up going back to the stock air box and stock jetting.

Post edited by: Murphyau, at: 2005/10/19 02:50

Normally I believe the older CV carbs, (I don’t know the Mikuni slide carbs well enough to tell if they are comparable), have got one air intake for the pilot circuit bleed pipe, one for the main circuit bleed pipe, and one for the vacuum piston operation (that will be the longish slot in the middle). And if the carbs have got a plunger choke, there will be one for the starter circuit as well, or, what’s most likely, it is shared with the air intake for the vacuum piston operation. Also the pilot and main circuit can share the same air intake.
So basically, when the air filter are blocking the air intakes like on the picture Daniel posted, it will affect the carbs all the way from cold starting to full operation; starter circuit mixture, idle mixture, mid range mixture, and vacuum piston operation. And even with the slides open, air will be drawn through these intakes. The purpose with the intake for the main circuit is to mix air drawn through the bleed pipe with fuel from the main jet, in the needle jet. This will give a better atomization of the fuel when it reaches the carb bore. If this air flow is blocked, or partially blocked, the mixture will be too rich, especially in the mid range. And if you add a problem with the vacum piston operation, I believe an attempt to tune these carbs will be a very frustrating job.

The problem will probably be most noticeable in low speeds, like Murphyau had, with the Mikuni slide carbs.

The cheap pods are usually 2 peice (air filter and carb mounting flange). The air filter is the same on all, the only difference is the mounting flange (60mm is pictured). On the smaller diameter mounting flanges, there is usually enough to grind away for clearance for the air passages. On the set pictured, if the flange was ground for clearance, it would not seal completely (there would be an air leak where the mounting flange slides on the air filter).
On some non C/V carbs the cheap pods will work fine, but still may need to have the flanges ground away for air passage clearance.
Usually K&N pods have K&N on them somewhere. You can usually get 4 cheap pods for the price of 1 K&N pod, but you get what you pay for.
Daniel

Dg, guess you can spend the extra money on K&N filters when ya win 24mm mikunis for 10 plus shipping, ya have any 26's ya want to sell on the cheap?

Great info - very useful. I will contact Emgo about this and see if they 1) are aware of the issue, 2) whether they will fix the design problem.

I did talk with a person in Emgo's product evaluation area about this - sent them a copy of this thread. So we'll see if they want to make any changes or not.