Keeway TX200G Air Filter Modification

12.7Hp stock on this machine was sufficient for me. With good torque of 13.5Nm, this bike (ownership 3months) served me really well for daily commuting and the occasional countryside riding. However, the maximum power and torque comes in at very high RPM that is typical of any motorbike. I hardly twist the throttle fully open, let alone for it to touch 6500rpm (for max torque) or 7500rpm (for max power). So what do one do? 
A typical hot blooded male with some knowledge with engine and working of a 4-stroke combustion engine (and years of modifying a family car to squeeze blood out of stone, so they say) will tell you this - Let the engine BREATHE. 
Open Pod
Going open-pod or those cone filter is actually the most logical way to go. But with my stock carb at 27mm, finding the replacement part is tough. The Keeway TX200G came with a huge air-box for the motorbike which actually takes up almost the whole space below the seat.

The two holes are the air intake holes, It is part of the triangular looking box below

While aftermarket open pod filter (legit performance parts) cost anything between RM60 to RM300, I ended up with a RM4 solution. Aquarium filter.
Yes, you read me right.

Original filter on left and Aquarium filter, right.

My whole reasoning for this is to actually free up some low end power. Restrictive intake hasten the pick-up of an otherwise spirited bike. A check on the local TX200G bike group has returned mixed review - as most of them that has modified their bikes removed the filter altogether and run them filter-less. 
This filter-lemma came about after I've learnt to tune the carburetor from a fellow rider - making the mixture a bit richer that stoic condition which has lend more power to the bike at low end. Essential for city riding as you want to get in and get out as fast as you can (away from distracted drivers). So, with the carb tuned, the air-filter needed to be sorted out to allow for more ready air flow at high RPM. Filter less, as they said (and experienced), was the way to go.
While I must admit I am tempted to do that, but I am conservative (slightly) with this approach as to prevent things like leaves or gravel from entering the carburetor and destroying whatever that works.
I know, there is NO way gravel or leaves could go into those puny holes. Lets see them again.

Leaves goes in under the seat? really? Stones??? Come on, you got to be joking me!

NO WAY, RIGHT? 

But I still take the more conservative approach. It has to have a filter - and it gives me excuse to modify something.

Disclaimer - I will not be responsible for any damages caused with this modification undertaken by yourself and this modification was done solely as an experimental purpose only. Please be reminded that if you constantly ride in highly dusty condition or take your motorbike into the desert, this modification is highly not recommended. Sand particles against internal moving parts spell disaster with capital F.

What You Need

1. The aquarium filter mesh obviously

2. Screw driver to fit your bike

3. Scissor to cut the filter

4. Some imagination (and ability to cut straight)

The dense filter sponge on right and the looser filter mesh on left. Shown original size.

The best way to do this is to cut the replacement filter using the original as the template. It is as simple as holding it firmly against each other and cutting it to size. 

No brainer which to use, really.

Once cut to size, place the mesh filter onto the filter holder. Note that the original filter has two holes. Those are there to hold (or sort of) the filter against the filter holder. As the original filter box is large, this setup was done to allow a stiffer "bracket" to hold the softer sponge. All you need to do is to press the mesh filter against the  holder and the protrusion on the filter holder will penetrates through. Easy.

Press it down. Done.

 Here is the completed filter in the filter bracket.

Awesome

 And here is the original filter in it's bracket.

Awesome too (in super dusty condition)

And once you are happy with how the filter holds up in the bracket (that including trimming off loose edges) you simply slide it back into the filter box. Screw back the filter cover, put back the fairing/bodykit. You are done. 

Yeah baby!

Verdict

• I started the motorbike and twisted the throttle. I immediately felt the lighter and less restrictive movement of the throttle, sign that the carburetor is working less hard to draw in the air. 
• The induction sound was louder as the original filter also serves to cut off the induction sound offering a slightly quieter ride. No issue here as it now sound "sportier"
• I took the bike out for a spin around the neighbourhood and OH BOY, the low-end torque and power were there. It is like less effort to move from 0km/h to 40km/h.
• I rode to work as it was school holiday (no driver duty) and on the clear road (limit 60km/h and 80km/h) the bike's pick up behaviour changed. At lower RPM the power could be felt and at Gear 5, I could still overtake cars moving at 70km/h. There is no need to downshift to 4th like I usually do.

Cost of modification - RM4 for filter (it comes in two sets of coarse and fine filter, I used only half of the coarse filter). 30minutes. Satisfaction overload.