View Full Version : SU Carbs Paper Air Filters

06-27-2008, 12:56 PM
Can these be cleaned? How often to they need to be replaced?

Mine are four years old and look dusty but otherwise fine.


Simon TR4a
06-27-2008, 12:59 PM
You might be able to blow the dust off with an air hose, or brush it off, but for what they cost I think I'd just replace them.

06-27-2008, 01:26 PM
Rule of thumb is to look at your drop light through the filter. If you can't see the light, the filter is dirty and should be replaced. Compare to a new filter ...

Supposedly, blowing them with an air hose isn't a good idea, as it opens up the pores in the paper and allows more dirt through into the engine. But I've done it too ... generally wind up replacing them anyway. I change mine every 10,000 miles or so.

A clogged filter increases fuel consumption ... doesn't have to be much to pay for new filters !

Don Elliott
06-27-2008, 01:36 PM
Look at what I did for my TR3A. I went to Sears and bought a foam filter for an industrial vacuum cleanrer and cut off two sections to fit over my air filters. Then I soaked some "AMS Oil for Foam Filters" over the foam.

It only takes a second to remove them before the VTR or TRA judges arrive.

Geo Hahn
06-28-2008, 06:31 PM
Off-road shops also sell stretchy fabric covers that go over the SU filter (though probably more $$ than the Sears version). A local TR3 driver uses them (lots of dust in Tucson).

I've always marveled at the original filters (on 3s and 4s) that look about fine enough to, say, stop a BB from entering the intake.