(Part 2) Best powersports filtration products according to redditors

K&N filters are popular. I got lucky and scored one for 6 bucks but it's still only 12 on Amazon - https://www.amazon.com/dp/B000E2CVDI/

I've got the same bike, I use this oil: http://www.amazon.com/gp/aw/d/B008MISDH4

With the K&N oil filter: http://www.amazon.com/gp/aw/d/B000E2CVW4

And as for the air filter I stick with the OEM one, you can find it for about $16 online.

Amazon Prime has the K&N delivered in one day... unless you can't wait :/

Alternative, here's a list of all filters that will cross reference to the factory installed part # 63731-99A

You have it correct. Change those things for 12v and add the stator for charging at lower RPMS. You can get by without it if you take off your battery after every ride to let it charge on a tender.

You can get that negative space if you want. You will need to remove the airbox (which removes the place to hold the battery) and replace it with a filter of your choice (I am using a cone K&N of the right diameter to fit my carb. It has it's own rubber mount that fits to the carb then you fix it there with a hose-clamp). Then I added one of these : https://www.amazon.com/Uni-Filter-UP-103-Clamp-Breather/dp/B000OO0XLS/ref=sr_1_1?ie=UTF8&qid=1492453036&sr=8-1&keywords=Uni+Filter+UP-103+1%2F2%22+Clamp-On+Breather

to the crankcase breather. The stock one is not a filter but instead a rubber hose that connects to the airbox. So on the stock setup you have Carb -> Airbox and Airbox -> to crank case. You remove the hose and put the little filter on and affix it with the hose clamp that comes with it.

After that you just need to find a new place for your battery. Since you want to have that empty space you can't put it there so that pretty much leaves one option : hide it within the seat or directly underneath it.

I don't know what kind of seat you want but if you end up getting a fibreglass bubble seat like this : http://i.ebayimg.com/00/s/MzIzWDUwMA==/z/NJcAAOxyUrZSs-25/$_3.JPG?set_id=2 you can hide it in the hump.

Otherwise you just lay it on it's side and have it attached to the bottom of your seat pan. Most of the time people buy aluminum flashing (very thin sheets) and cut+fold the metal into a little box/pan thing for the battery.

Doing this does require you to modify the existing wiring but it's simple you're simply extending the wires for the battery so they can reach the new location and you hide all those wires by tucking them underneath the seat pan.

You have options I think you can make it work :)

I'm still working on my project but I just put on both the K&N filter and the little uni filter on the crankcase and it's starting up and idling fine. I actually couldn't get it to idle with the stock airbox but it does with my new setup so that's a bonus :) But I will probably still need to tune the carb with a new jetting. Please understand that if you change your airbox and do like I have done you might need to re-jet your carb. It's not very expensive to do that though and there is a service off of ebay and amazon that is very good for that. Here's a quick video I uploaded hope you can view it : https://streamable.com/uuyc9

Note: I replaced the OEM muffler with a dunstall replica from Ebay which has no interior baffling or fibreglass packing. Sounds beastly for a single cyl but I will be putting in either a baffle or some fibreglass packing to reduce the Db level as it is very loud and you won't impress no one sounding like a bat out of hell on a 125cc :P

KN-123? Should have the rings on them already, but if not see link.

8 bucks on Amazon

I've had good experience with Uni pods. Dip them in a bit of oil before installing and it'll give you a more favorable flow resistance. http://www.amazon.com/Uni-Pod-Filter-Kit-Chrome/dp/B000GZMZKC/ref=sr_1_10?s=automotive&ie=UTF8&qid=1417452486&sr=1-10&keywords=uni+filter