Interesting behaviour...

Hi all

My tank range since I've had my 03' (few months) has only been 130-140 miles.

I've not done anything to it other than an oil change so today bought a new air filter for it.

Just lifted the tank and there was already a K&N in there, but it very dirty - black and filled with crap.

Fitted the new filter (another K&N) and tried to perform an ECU reset (I'd seen it on a forum somewhere)
Disconnected the battery for 10 mins and then fired up with no throttle, and left until the fan cut in/out a few times

The thing is - when it came down from fast idle, my idle was 950 rpm? It was set at around 1250 previously...

What goes on??!!

For your info bike has -1 on the front and some Staintunes.

Cheers.

 

Might want to change the plugs as well. If the low idle still there try to adjust by turning the knob on the right side between the fairing and the engine cover.
https://www.google.com/search?q=vfr...-starter-valve-syncronization-vtec%2F;640;480

 

Thanks.
Yep reset the idle, just wondered if changing the filter alone would have such an effect? The old one was minging!

 

I would think the idle should be higher since the airflow better :noidea:

 

If the fuel economy doesn't improve, consider the thermostat. After warming up, the engine temperatures should stay above about 170F/76C. If not, the thermostat is probably stuck open.

 

With the engine starving it will work harder, so a new clean filter can cause the idle speed to drop. It can also make it rise. Depending on how far the ecu has gone to correct the issue and keep the engine running.

If you filter is that plugged, change the plugs. They will be burnt or carboned from the lack of air.

Air filter should be checked/ cleaned everytime you change the oil. Good policy and guarantees good service from your bike.

Just for your information the -1 on the front sprocket, that makes your chain go around a tighter circle. This will cause early chain wear and can tear out the o-rings in the chain. A +2 on the back does the same job as a -1 on the front, but without the chain issue.

 

Finally got around to riding it after changing the filter. Also filled it with Tesco's finest ultra unleaded (99RON I believe)
Much much smoother. Quicker - I don't know, and only did about 50 miles so unsure if the economy has been affected either...

Happy though

 

Make sure air pressure of the tires are within the recommended spec.
A low air pressure can cause low MPG. A fuel injection treatment can help too.