Replace the foam inserts in air filters?

[michaelpthompson]

Getting this '75 XS650 ready to ride, I took off the air filters. The boxes and screens are fine, but the foam inserts are pretty rotten. Looked on MikesXS, but I don't see just the foam inserts for sale, and the boxes are too expensive to replace for no reason. Can I just cut some furniture padding or something to fit? Any advice on an easy and inexpensive fix for this?

Thanks

 

[5twins]

You can re-wrap the air filter screen "cages" with foam. UNI sells bulk foam in sheets .....

http://www.unifilter.com/accessories/

This stuff is pretty cheap and made for this purpose. I don't think I'd take a chance on furniture foam. If the gas and oil fumes start breaking it down, it'll plug your carbs up big time.

 

[michaelpthompson]

The stuff that wraps around isn't in too bad shape. It's the part that's inserted into the passage that has deteriorated.

 

[Brassneck]

perhaps a pic? Not sure what part you're referring to. Buying new ones while a little more expensive, will probably last another 40 years.

 

[michaelpthompson]

This part here:

These go between the air intake and the box with the screens.

 

[Brassneck]

Sorry. Pics didn't come through?

 

[torider]

I agree you can just buy a UNi filter and cut out the specific size you need. It do work great.

 

[weekendrider]

Maybe what OP is looking for.is the baffle material. Not filter foam?

 

[michaelpthompson]

Strange, I can see the pics fine on my screen. "Baffle" may indeed be the correct word. I'll attach these pics a different way.

 

[Brassneck]

Is that really stock? I haven't seen something like that on an xs...looks like sponges and perhaps the previous owner got creative. Do you have the standard filters as well...in addition to those?

 

[5twins]

Yes, that was stock on '77 and older models with that airbox. Yamaha calls them an "intake silencer" so it appears they were more for noise control than filtering. You probably don't even need them. Yamaha didn't even use them in '78 and '79.

 

[Brassneck]

Cool, learned something new!

 

[michaelpthompson]

Me too, but that happens to me a lot. They fit into the air intake passage leading to the stock filters, which I do have, and they're in decent shape.

 

[XSLeo]

Just leave them out. I did on my 75, Well until I swapped them out for pods, then Uni Filters.
Leo

 

[torider]

Just leave them out. I did on my 75, Well until I swapped them out for pods, then Uni Filters.
Leo

This is what I did, Left them out after I had an idea of replacing it with Uni filters that I bought from 4 wheel online. Intentionally it was for my quad, but changed my mind and got it for my bike.

 

[michaelpthompson]

Here is the diagram from the Yamaha parts list. They're really just pieces of foam. That's why I thought just cutting some kind of foam to fit might work. I could also just leave them as is. They're not falling apart yet, but look to be close to deteriorating. Or, as you say, just leave them out.

 

[nhsteve]

I suggest leaving them out also. If you ride in the rain a lot, they turn into sponges and restrict air flow. They were intended to quiet the intake noise.

You'll be fine without them I think.

 

[gggGary]

yeah that foam is incipient FOD get rid of it, (very carefully) some 100 point restorer would pay big bux for intact ones.

maybe not to this degree.

Got first start on an abandoned Radian project 600 today. turns out there must of been some rags in the intakes before the carbs went on..... Seems they passed through without harm but watching the exhaust sure was interesting for a while!