I had read about cutting the sideways ridge off the air filter in the registry but the results where never exactly specified. I had also noticed that the K&N filter had no sideways ridge.
Before
After
No need to remove the tank. Just undo the two front bolts and pivot on the rear.
Unscrew the 8 airbox cover screws. Remove the front two screws (do not drop them)
or the cover will jam as you remove it.
I cut the ridge down to the level of the air filter element. I used wire cutters
which were a bit rough so I filed it smooth with a wood file. Neatness counts, we
are talking about air flow here. I then unscrewed the holder from the airbox cover.
There has been some discussion about what function this ridge performs. One theory
is that it is simply there to reduce the intake noise.
My bike has stock standard carbs but is fitted with Staintune stainless low mounts
with the baffles in. With this mod it burbles about 50% less, feels about 30% smoother
and the throttle is 10% more responsive. While this may sound like an objective
assessment it is, in fact, very subjective. The change is only small with the most
noticable thing being that it is smoother. Fuel economy seems about the same.
If you do not like it then a new air filter will cost you AUD$75 and you need to
replace it every 18,000 km anyway.
What does not work on a VTR;
- Removing or modifying the snorkel (rubber inlet) - popular on VFRs
- Removing the airbox cover while leaving the airfilter in place - popular on Ducatis
- Drilling holes in the airbox cover or airbox