Can anyone confirm that the 1986 1WG and 1989 3TJ have the same factory air filter?
I brought a race bike in bits and the air box was off the bike. It has a 1WG filter that appears too tall by about 10mm to fit in the Airbox snorkel. Seems very unlikely that they would have made it 10mm taller but it simply will not fit the Airbox! Frame is a 3TJ so the Airbox may be also....

The 1wg filter is taller than the 3tj, so have a 3tj airbox and a 1wg ( or fzr600 3he they're the same) filter. If it's a k+n you could twist and squash it maybe

Thanks mate thats a great help, I just couldn't get the air box back together with the supplied factory filter and was starting to doubt myself. I will get a 3TJ filter...

Lol cool