Air Filters

[michaelphillips]

well the experts say~:
Replacing your air filter helps your car run efficiently.
Another outdated claim, dating back to the pre-1976 carburetor days. Fuel-injection engines don't get economy benefits from a clean air filter.

but the experts are wrong about the air filter... a clogged or dirty filter restricts air flow causing you scoot not to run at top efficiency.. so if your scoot starts to loose 2/3 mpg on your usual runs, then its probably your filter.

So i would say do the below and your scoot should be everlasting

Check your tire pressure. Making sure your scoots tyres are set to the recommended pressure can increase fuel economy by as much as 3.3 percent.
Breathe easy. Replacing a dirty air filter with a clean one can save up to 10 percent on fuel costs.
Read your owner's manual and follow the manufacturer's recommended maintenance schedule. If it's time for a tune up, do it and you can realize up to a 4.1 percent increase in fuel economy.

[Funkycowie]

looking back at this I probably meant 15 miles per tank and not mpg

[Data]

Certainly makes a big difference. I just vacuumed my Burgman filter and I got another 4-6mpg! But it needs replacing now after another 3k miles. Are you still thinking you have a dodgy fuel pump or is that put to bed now?

Can you explain to me why increasing airflow improves mpg.

My brain can't understand why this would be, as I thought clever FI systems would increase fuel flow to maintain the desired A/F mix. So I can understand it may help overall output but how does that improve mpg, or is it something to do with efficiency?

Help!

Hi buddy, yes the fuel injection system will compensate to a limited degree if the filter is dirty but it won't compensate enough if the filter is very very dirty. You'll run rich, wasting petrol and dump lots more rubbish in the oil. And if the fuel injection sensors are busy compensating it means you will lose performance in various situations and at certain throttle and load settings.

[SkuTorr]

Your injected bikes also have a TPS...Throttle Position Sensor, to know when you go full throttle from cruise and to increase the fuel in the A/F ratio from a stoichiometric 14.7:1 ratio to 12-13:1 for best acceleration. A dirty filter keeps you at the rich end of the spectrum, as it is always pushing the limits of your mapping. It can't minimize the injectors' dwell (open time) as the TPS says you are asking one thing, and the MAP and O2 sensors say another.

Also, you CONSTANTLY need "full throttle" because it's running restricted and down on power...

My previous Scoot was a Majesty, and power seemed a bit disappointing after I bought it with 700 original miles. I finally checked and both air filters were FILTHY. Changed them and WOW, it hauled BUTT!

Unfortunately, the Majesty filter design and positioning is STUPID and they dirty-up VERY quickly. Whereas my 6,500 mile Tmax STILL has the original, CLEAN air filter...

[gn2]

If there's not enough air you need to burn more fuel to get the same power?

[Bluebottle]

Don't forget that efficiency isn't all about mixture being rich/lean.

Your engine is just a big pump.
If it has to suck through a dirty filter it has to suck harder. That means more effort - requiring more air/fuel/energy from the engine for the same turn of the wheel.
Mixture is only one half of the story

(actually its only a third because improved gas flow can destroy performance. High flow K&N style filters, gas flowed heads and "performance" big bore exhausts etc. can bollocks the pulses and swirl patterns the engine needs and were designed into OEM gear)

[poldark]

Thanks guys, understand it a bit better now.