Air filter upgrade...


New Member
Local time
3:39 AM
Aug 15, 2008
San Diego, Ca
i was thinking, the bike engines have the same concept as say a truck engine... and when i changed my air filter to a k&n style intake & filter i saw much better performance on my truck... so.. does anyone have a web site, link, idea on air filters? was looking to increase the airflow and add some style with a more agressive looking filter and i looked into ebay for maybe a pocket bike style filter and 'buy it now' thinking it would fit but now i'm thinking it wont... any ideas out there?
intake is pretty much fine the way it is, if you want power start tinkering with the exhaust
well i pulled out the silencer on mine. big gains. but be warned it will be louder then anything on the street
well i pulled out the silencer on mine. big gains. but be warned it will be louder then anything on the street

not sure in this case
but - with 2-strokes back pressure can be important

rings a bell also ---
small Honda when I was young with a straight pipe
thought that was so cool -- very loud for a 90cc
people would turn their heads close to a block away

today many with MBs wish to STAY LOW KEYED


Ride That Thing - Mountainman
Here is the K&N that I have, expensive and not much of a performance gain, but it is a K&N and it fits the stock carb.

Here is a thread on a tuned pipe install using a readily available pocket bike pipe.
Make sure you read the thread all the way through as different mounting and tuning options are discussed.
i still have the cap on my exhaust just gutted out the silencer so i still get a bit of back pressure. but anyway in my state (connecticut) were aloud to ride anything 50cc or under without any kind of license or insurance or registration. only time ive had to deal with the cops is them asking where they can get one too!
Two stroke motors are different from four strokes in alot of ways.

There is commonality in the fact that better breathing will help both but there are also differences. Namely in this case that a 4-stroke mill will respond in a much more marked way to induction improvements.

To tune a two stroke for maximum power you will need...

Adjustable high throughput carb (17mm has been fitted to commercial bikes on a 50cc mill). DO NOT forget to tune the mixture properly in all riding modes or you WILL destroy your engine.

Tuned Pipe - MUST be suitable for the engine size - for example a pipe for a 100cc motor will not work with a 50cc engine, at least not properly. A pipe for a 30cc motor will throttle a 50cc and so on.

Reed valving - With a two stroke you dont have a valve system as such, unless its a rotary induction machine. The problem with that is you get charge leakage from both the induction and exhaust ports. Reeding the ports means that you have a non return valve on both ports and means you get a charge into the cylinder that stays there in its entirety which means more bang and therefore more power.

These changes will give around 5/10%, up to 30/35%; and 10/15% or so performance increases respectively.

Additional devices such as race spec CDI modules and Nitrous (wet or dry) kits will also boost performance but do you really want a pushbike that does 55?...

However these performance increases may result not in higher top speeds but a much more powerful and flexible powerplant in mid ranges and torque increases which make for better hillclimbing and mid to mid-high range performance.

Hope that helped

Jemma xx
Intake helps, get more air into the air filter cover box, or get a cone filter for your bike motor. Exhaust helps too, but intake matters more.

2 examples:

Just removing the air filter box cover to get open air into the stock air filter on my bike-trailer 196cc 4-stroke made a VERY noticeable difference in acceleration and torque, and much better sound under load. It also helped the engine rev better in the high RPM. Exhaust still stock.

I had a 2001 Ford Ranger with a high-revving Duratec 16V I-4 engine, and after making a huge 6" x 3" breathing-vent in the airbox in place of the stock 2 inch hole for the air to enter, the difference was amazing! Engine was much louder under load, revved to 6000RPM limit MUCH quicker. That was with a STOCK air filter too! Adding a K&N made it even better, but the most difference is getting the air to flow better in the first place. BTW, exhaust still stock.

2 strokes may be a bit different, but I highly recommend opening the intake flow on any engine to get better power. Always worked for me, and costs nothing to modify an airbox to flow better. Don't worry so much about the air filter, the air has to get to it first.
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