Batavus air filter, Uni pod 4200 experiences?

I was reading up on the Bat wiki and such and found in the HS-50 page that uni-pod makes an air filter " that works better, model # UP 4200." I'm looking for little things to increase/maintain the performance of my bike.

Anyone have experience using this filter on an Encarwi?

I looked at the link in the wiki to purchase and I'll probably get one. Not too crazy about the turquoise though.

Anybody able to find one in black or something? I checked and it appeared they had a black one listed but there was a multitude of measurements and selections in the "Size" drop down. The site linked in the Wiki doesn't have such options and I assume that one is a straight fit.

What have you guys done?


Re: Batavus air filter, Uni pod 4200 experiences?

The different colors of UNI filters are not just for style. They denote the amount of flow that particular filter has. I believe UNI black foam is the most porous.

As far as if it will fit or not I would just bust out the calipers and measure the diameter of the carbs clamp area on the front.

Also you do realize you WILL have to re-jet when putting on a high flow filter. Encarwi carbs use bing jets just FYI.


Re: Batavus air filter, Uni pod 4200 experiences?

Yeah, thanks. When I take apart the carb I'll have to see what jet is in there. The kid I bought it from believes there's a 58 in there but the bike says its a 25mph version. When I get back from vaca I'll be checking the carb model. What would you suggest I jet to if I make this change?

Also, I read some input of yours on other threads. You've got great stuff to say. Have any suggestions for other simple performance enhancers for my bike? I'm learning how to do this stuff from the ground up so I really do appreciate feedback.



Re: Batavus air filter, Uni pod 4200 experiences?

You should be jetting up possibly 3-4 jets sizes with a high flow filter. Also have you read about the reed mod? The stock reeds on those bikes is one of their biggest handicaps. It seems daunting at first but if you have the tools it can be done fairly easily.

Here is how you do it.

Tools you need:

1) Dremel with a good assortment of bits.

2) Some hand files to tidy things up

3) A set of metric or SAE taps (depending on the hardware you choose to use)

4)Screwdriver set

5)Set of hammer punches


7)Exacto knife with new blades.


1) Buy some of this

2)Remove your reed block and do everything in

this video up to where he starts to tap holes in it.

3)Drill and Tap holes where the old reeds were "riveted" on according to the screws you decided to use (keep in mind they need to be low profile).

4) Use your old reeds to trace new square ones on your sheet of polini carbon fiber.

5)Using a brand new exact knife blade cut out your reeds.

6)Use the proper size punch to put some mounting holes in your reeds.

7)Put your reeds on with your mounting screws and remember to use loc-tite!

Vwala your Batavus will now flow much much better and you will have to up-jet again.

Good luck


Re: Batavus air filter, Uni pod 4200 experiences?

Thanks a lot man, really appreciate this!


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