Custom UNI Foam Motorcycle Air Filter

No real need for this project, just something fun and easy to do. I got my 1986 Honda Shadow VT700c about a year ago and have had a great time riding it. I figured the air filter probably could have held out a bit longer, but due for replacement. Prior to undertaking this project I ordered a replacement OEM filter in case I was unable to finish the project in a day I could still ride my bike.

This one was nice and easy. Just remove the paper media, clean the filter frame off and glue in the UNI foam. Total cost was around $15, about the cost of an OEM filter. I picked up the UNI foam at Cycle Gear. The glue was Silicone Adhesive I got at Autozone at some point.

The old filter material didn't look *too* bad, though the clean areas probably don't get much air flow through them (thus why they are clean).


The paper media was easy to remove, just grab and pull.


I held the foam up to the filter housing and cut it a little oversized to ensure a snug fit.

Kayla couldn't resist a pose with the foam and filter housing. I think this was taken after a thorough cleaning with brake parts cleaner so the silicone adhesive would stick properly.

I used a bunch of the adhesive, probably too much, but that's how I do things. I think that's about a 1/4" bead all the way around. A few parts are a little thick, a few a little thin.

I used some packing tape to help hold the foam on the housing properly, though there was really only 1 edge that needed it.

Here it is starting to set up. Before the silicone set up I went around the inside seam of the filter and squished the silicone flat, removed what would come out. Make sure that none of it will come off and get sucked through your engine!

I used Kawasaki filter oil that I had laying around from the days of my 1983 KZ750. Maybe if I keep this bike long enough I'll be able to use the can of filter cleaner too!

And here it is all installed on the bike. You can see the oil starting to pool up at the bottom of the filter. This is of course due to my putting too much oil on it and/or not squeezing the excess oil off enough. I threw some kitty litter on the floor where it spilled out and fired up the bike to burn the rest through the engine.

As far as performance, the bike seems to pull a little harder at lower RPMs, and I like to think it sounds nicer. Both are probably just placebo effects. If I notice a difference in the MPGs I'll update the post. My average on the bike is 48.7 with a high of 56.1. The last 3 tank average prior to this filter change is 50.4, I've been taking it easy lately :-).