Air Filter 1980 R100-T

I have a 1980 R100T under restoration. It arrived with an K&N air filter. After reading Snow Bum, I purchased a new "thought to be OEM" from A&S Motorsports in Sacramento. The filter did not fit, though the fische number was correct. After much head scratching I took it back with questions about correctness. The parts manager finally came out from the back and said the 1980 was a single year concoction of air filter housing that required a special filter that was no longer available. The listed part #13721337080 doesn't fit.
Long story shortened, does anybody know where I might look to find an original or original copy filter the is NOT a K&N?

No one makes an airfilter to fit the 1980 R bikes it was just one special year and then they made changes.

I have a friend with a 1980 R100T and he made small cuts in the K&N to make it fit.

So, I take it that the 1980 T takes the square filter not the round one? I thought the square setup came in 1981...or did they begin to sneak it in during the 1980 model year?

Do you have the round or square housing? My friend had the square housing so he cut the center out of the old filter then found a flat filter at the parts store for a car, then he cut it to size with a band saw and stuck it inside the old filter body and sealed the edges with silicone. A true airhead approach that worked for him!

Filter Housing

The filter housing is square with the two cone shaped tubes protruding toward front of bike. I suppose I am left with cutting out the K&N filter and installing a paper one from a car. Seems so 1950ish but it should work with a little patience and stubborn persistence.

My understanding is the K&N's pass a lot of dirt until they are dirty and clogged. Never had one never will.

I have had 1 K&N filter on my bike for over 25 years and 450,000 miles, If you clean as instructed and use the proper
oil it will last forever.
My friend has made small cut on each side of the square filter so it will fit the stock 1980 housing.

It's a simple fix.

Airbox

Yes, the 1980 had a one year only filter that is no longer available. The only difference between 1980 and the newer models is the lid with the snorkels.
So just get a newer, plastic, lid and all will be well.

1074 said:

Yes, the 1980 had a one year only filter that is no longer available. The only difference between 1980 and the newer models is the lid with the snorkels.
So just get a newer, plastic, lid and all will be well.

Click to expand...

This is the best solution.