Aftermarket Stock-type Air Filter ('83 Special)

[YamadudeXS650C]

When I bought my '83 Special this summer the PO had recently purchased new aftermarket filters for the stock air box. Pics attached of what I found. He was a MikesXS customer, so I believe them to be Mikes item # 15-0655.

If someone else has these particular filters, I have a couple questions:

1. Should they be oiled?
2. The visible yellow foam seems to be quite porous; is there a more dense inner layer? its hard to see into the inside....

Thanks

 

[Brassneck]

I have similar looking ones, but I have a '79...I did NOT oil them, I don't think you need to.

 

[YamadudeXS650C]

Thanks, Brassneck.
I just heard from MikesXS, who said the same.

And what do you think of the porosity of the yellow foam? seems like dust will get through....

 

[Brassneck]

If it's in the stock airbox, it's not likely to be an issue. I've not experienced any issues at least.

 

[fredintoon]

Hi 'dude,
FWIW, the stock Yamaha filters look like they skinned a teddybear to get the filter medium.
I don't suppose the MikesXS coarse foam is any worse.

 

[gggGary]

FWIW I take the stock frames, strip the "mouse hair off, cut and fit UNI filter foam the fine green version. Glue the ends together with bumper epoxy or weatherstrip adhesive, couple wraps of bell wire to hold it in place I buy UNI sheets that are about 12x16 and I lightly oil it " sometimes" You can also go to the local lawn and garden place a Kohler prefilter foam is big enough to give you foam for both sides. It's not as thick as the UNI sheets. pretty sure it's the same stuff. I agree that mikes foam is not fine enough.

 

[YamadudeXS650C]

Thanks Gary,
I think I may get some foam sheet stock from Uni, as you suggested.

Just now, I decided to make a small incision into the foam. I found a thin, inner layer of dense foam. Both layers considered, however, I don't feel very secure with these filters. I'll go the Uni site and look into the sheet stock.

BTW, Russ at Mike's said that he is about to sell the last of this type, and the new stock looks better.

 

[YamadudeXS650C]

Fred, I think I experienced some of that Teddy Bear skin this spring when I tore down my '67 YR1 350 Grand Prix. The air filters were as stinky as a dead corpse, and resembled week-old road kill. I sold them to someone who was going to do what Gary suggested.

 

[pamcopete]

Got to Home Depot. Buy a Briggs and Stratton #5052 air filter for $13. Sometimes available on Ebay or Amazon for much less.

Saw it in half.

Fab an "L" shaped plate 2 7/8" wide to seal the end and top from a piece of roofing flashing.

Shape the filter half and plate to fit inside the filter housing, flat end on the bottom. Trim the metal plate to clear the housing cover. Use Permatex Clear RTV Silicone #66B to seal and secure the plate to the top and end of the filter half. Clamp for 1 hr. to set the RTV.

Finished product.

Installed in my '81 Special II. I used a piece of 1/8 aluminum as a spacer and reinforcer for the spring clip that holds the filter in place. You could use the salvaged back from a filter for the same purpose.

Work slowly and carefully. Do a trial fitting in the filter housing with the lid installed to ensure a proper fit before you apply the RTV. Trim the lower left (left side) and lower right (right side) corner to clear the cover when it is installed. Make sure that the far inside edge covers the opening to the carb.

 

[YamadudeXS650C]

Nice fabrication, Pete !