Re: *Why* aftermarket air filters (UniPods) affect fuel mixtures in CV carbs.

[danv93]

First off, I'll begin by saying I'm pretty new to working on motorcycles. I have recently put pod filters on my bike. After doing so, I noticed that I started bogging down at higher RPMs. After reading a couple things on here, it seems as though the difference between pod filters and air boxes is in the velocity at which the air enters the carbs because of the size of the openings. If pod filters create a lower velocity of air, couldn't you increase that velocity in by decreasing the size of the opening with a rubber washer? Or will that restrict too much air as well? Thoughts? Advice?

Also, I'm noticing that I'm only getting about 20mpg and there is a lot of 'gassy smelling' smoke coming from the crankcase breather. Does that mean I'm probably running too rich?

[JPaganel]

Synthetic.

Would that be motorcycle-specific marmalade? Cuz automotive marmalade  wouldn't work.

[Pat Conlon]

First off, I'll begin by saying I'm pretty new to working on motorcycles. I have recently put pod filters on my bike. After doing so, I noticed that I started bogging down at higher RPMs. After reading a couple things on here, it seems as though the difference between pod filters and air boxes is in the velocity at which the air enters the carbs because of the size of the openings. If pod filters create a lower velocity of air, couldn't you increase that velocity in by decreasing the size of the opening with a rubber washer? Or will that restrict too much air as well? Thoughts? Advice?

Also, I'm noticing that I'm only getting about 20mpg and there is a lot of 'gassy smelling' smoke coming from the crankcase breather. Does that mean I'm probably running too rich?

So if UniPods decrease the velocity of air going into the carbs, couldn't you modify them to increase the velocity? I tried putting rubber washers inside mine to decrease the hole size and therefore increase the air velocity. I don't bog down in the mid range anymore. My only concern is that at higher speeds it may not be getting enough air and overheat the engine? Anyone think the washers are a bad or good idea? Thoughts? Advice?

Bad idea.
Setting aside the ease of carb maintence issue (no airbox to r/r) UniPods shine in the decreased restriction of air in the upper rpms...the kookaloo zone. Washers, or any other type of air restrictions would defeat this benefit.
In the low to mid range rpm zone, there is no appreciable performance difference with UniPods. There is a potential of your engine running leaner from the lower air velocity (lower slides) but you can compensate for that by running #40 pilots (which you should anyway) and shimming your needle 1/2 step.
You can go up 1 or 2 steps on your main jets if you also have a aftermarket (more efficient) header system.

Jets are easy, you only have to do it once.

There is no need to start another topic when you have asked already this question re: restrictor washers.

Yes, you are running too rich...20 mpg indicates something's wrong.

1) Check your choke linkage. Make sure your choke plungers are fully extended when your choke knob (or collar) is in the off position. Make sure they move in and out freely. If the plungers are stuck or sticky or even slightly depressed, you are drawing fuel through the choke circuit and running fat...then,
2) Check your float heights...float levels set too high will cause a rich condition, look for a stuck float, then
3) Check your jets and needle position...and while you're in there,
4) Clean your carbs.

The UniPod filters have nothing to do with your symptoms.

[Mark Olson]

danv93,  Yes you are running WAY rich and It wasn't the pods that caused it.

How was it running before you switched to pods?

You Putting a restriction in the air flow is compensating for bad carbs dumping fuel.

Something is messed up in your carbs / choke just like Pat already said.

Here is your second opinion...Go clean and inspect your carbs.

[movenon]

As noted above.  The POD's are not your problem.  The short answer is fix your carbs or have someone like Randy at RPM rebuild them.  If you are runnnig as rich as you indicate you could be washing down your cylinder walls making a more expensive problem. 
George

[giantkiller]

Also you may be filling your crank case with fuel.  Float, needle, seat problems. Not sealing. Filling your cylinder. And draining past your rings into your oil.when bike is shut off. (Didn't see what year bike you have) would certainly drop your mpg.

And I put an air horn in the space gained not having the air box. On both the 86 1350, and the 89. The turbo bike is getting a turbo where the air box used to be.