Dilemma: Fabricate new air filter or bodge the old

I have a 1980 KZ250. Air filters for this bike are no longer available. The original filter is rectangular (romboidal, I guess), fits inside a plastic box that sits within the saddle support frame (above the battery), and is fed by a hose for ventilating the crankcase.

I've bought a round UNI filter that should go nicely on the throat of the carburetor, but to go that way, I think I have to break the box the old filter sits in (to remove it) and I imagine I'd just vent the PVC hole to the air or plug it.

Instructions with the foam filter say I may need a tune shop to adjust the carburetor and change a jet since the air flow will be different. Huhh?

I like saving the old, but, heck, I can't find a filter. I wouldn't mind if my bike breathed better, so the round foam filters seem right. Anyone been down this road?

Thoughts anyone? Any advice appreciated!

Doug

If it is anything like my KZ250 I had it wont run very well with out the air filter , Might try cutting out the paper part of the filter and cutting a piece of foam to go inside the metal box left ,, I have used Lawn mower foam filters Cut to fit what I needed it to be

According to Kawasaki.com your bike takes part number 11013-1030 (I'd check the number with a dealer). These folks claim to have the part (NOS) in stock:

motorcyclesunlimitedtx.com/search.php

Thanks. I had a Kawi dealer looking for it. They actually recommended the UNI foam cylinder approach, but I actually like the idea of cutting foam to fit the metal box left when the paper is cut out. I don't mind leaving a lawnmower engine to a lesser filter, but I wonder if I risk anything with my 27 year old gem, if I go that route.

Doug

The Thing is I have a NOS one around here somewhere BUT can not find it . Must have got lost in the move last year ,, Why would you think a foam filter is less of a filter than the stock KZ one ? It might really be a better one ? another Idea is to get a sheet of air filter foam , I think Uni makes it or another off road filter company and use that if that is more comfortable than the Lawn moer type

I did find my NOS Filter But the Number is 11013-1039 if it can work for you PM me I will let it go cheap ,,

Let the PCV port breathe free with a hose to the ground. If you plug it, oil will blow out through the gaskets.

Well, it doesn't look pretty, but here's what I've done. I took apart a $15 UNI cone filter and gently flattened the foam. It almost wide enough to cover the air feed opening in the filter box. I've used black duck tape on both sides of the foam to make a "frame" that I've taped in place around the edges of the metal filter box, and I've tapped it in place inside the filter box. Getting it back out will be a pain, but it'll probably breathe better than the original.

Do I NEED to use air filter oil on the foam? The instructions say to do so, but I imagine the duck tape will lose its adhesion if I do.

Soon to roll on my 27-year old gem,

Doug

Doug wrote:

...Do I NEED to use air filter oil on the foam? The instructions say to do so, but I imagine the duck tape will lose its adhesion if I do...

You really do need to oil foam filters. That's how they catch stuff. Otherwise, it's pretty much a loose screen that only blocks out... basketballs...

By the way, I don't see your picture...

Well, it runs pretty well. I still have a stumble/cut off issue at about 1,200, even after warmup.

Thanks for all the help.

I'll oil the foam screen I made and go from there. If it fails, I believe I have a NOS coming, so we'll see.

Doug