Topic: uni air filters

[carl550k]

 anyone ever have a uni foam filter they could not get clean? i bought mine about 4 years ago, oiled it up as the directions stated. it worked great but over time it has started to make my 76 550k run rich.this past winter i rebuilt the carbs to factory spec with new kits. i also put the stock 4/4 exhaust back on thinking my mac 4/1 was creating the rich condition.i have replaced the points and condensers last summer, the carbs were synced last week, valves set, new plug caps and wires.it still runs rich, the only thing that seems to make it run better is removing the air filter. runs awsome then, but put the filter back in and the plugs will foul out after a few miles. i have tried to clean with everything from dishsoaop th simple green, have never used uni filter cleaner. any and all suggestions appreciated

[TwoTired]

What did you oil the UNI filter with?

[carl550k]

 i bought filter oil in a spray can from the local honda dealership. i told them i had a uni faom filter and they gave me the only filter oil they had.the can does say for gauze type filters, nothing about foam. could this have shortened the life of my filter?

[forwheeldrift]

that oil could be to thick or something

use a air compressor from the inside out, don't re-oil see if that works

did you clean and oil the filter regularly over the last 4 years?  if not get a new filter

[eldar]

Ok you might laugh but have you tried to clean the filter with Dawn dish detergent? None of the fancy stuff just the plain dawn.
I have used it for oily or greasy parts and it works very well usually

[carl550k]

 have tried all kinds of dishsoap including dawn. also did the compressed air. today i cleaned and dried thouroughly and reinstalled, after a short ride came home, pulled the plugs and they were black. btw i checked the plugs before i left, they were chocolate brown, this with no filter.

[TwoTired]

I would try the uni filter cleaner which should be safe for the uni foam.  But, then I already have some.  If you don't wish to get some of that, you could try mineral spirits from the hardware store.  Yes, it's also called paint thinner.  It's what I use in my parts solvent tank to clean oily things.  I've cleaned the foam element in the oil breather with it without deterioration.  But, if you are planning to replace the filter anyway......?

cheers,

[Jinxracing]

Sorry to hear that they're not coming clean. If I were in your shoes I'd be trying every solvent in the house; paint thinner, gasoline, Goof-Off, lighter fluid, Windex, whatever. Either it cleans the foam or eats the foam, but if you can't get them clean you'd be buying new filters anyway, right?

My foam filters look as though the foam element can be replaced without buying complete new filter assemblies...do you have that option with yours?

[csendker]

I have a can of Uni cleaner (& a can of Uni oil). If you want to give the real deal a shot, let me know and you can borrow the stuff - I'm over in Lancaster.  Well, actually I'm in Connecticut right now (work), but I'll be back home by Friday.

[78 k550]

It sounds like you have done what you can.
I would email them or call them (UNI) and explain what you have going on.

Paul

[eldar]

So your plugs are a chocolate brown WITHOUT the filter? Seems to me that is already too rich and it is not really the filters fault.

[carl550k]

went today and bought UNI cleaner and filter oil. used almost half the can of cleaner, am letting dry good overnite. i'll try oiling it tomarrow and see what happens. if it doesn't work at least i already have the oil and cleaner. btw the foam part of the filter does come apart from the plastic housing. as far as the plugs, they are a few years old and maybe fouled one too many times. the carbs are just rebuilt with new jets,needles,ect. the floats are right on at 22mm. mixture screws 1 1/2 turns out. also stock 4/4 exhaust. everything set to stock except for the paper air filter.

[TwoTired]

the carbs are just rebuilt with new jets,needles,ect. the floats are right on at 22mm. mixture screws 1 1/2 turns out. also stock 4/4 exhaust. everything set to stock except for the paper air filter.

Were the needles aftermarket or from Honda?  Others on the forum have found aftermarket needles run richer than the stock ones.  They had a different taper profile.

Cheers,

[carl550k]

the carb kits were from k&l. i checked the needles before i put them in. they looked identical.

[cardrell]

i may have missed it but did you replace your spark plugs.they could be not giving a good spark and thats why there black.
or clean them of realy good with brake cleaner.carb cleaner leaves a residue

[TwoTired]

the carb kits were from k&l. i checked the needles before i put them in. they looked identical.

I'm not saying the needles you had weren't identical.  But, I'd be highly impressed if could you tell a 0.2 mm difference by sight, or a 30 minute angle difference over a 55 mm length.
Here are some measurements (caliper) beteen CB500 needles and CB550F needles
Jet Needle and taper      2.515ø-2º30'-4 grooves           2.495ø-3º00'-2 grooves
Jet needle number               272304                273004
Jet needle  OAL                    5.57cm               55.56mm
Jet needle diameter at tip      1.25mm              1.01mm
Jet needle diameter at 1mm   1.63mm              1.45mm
Jet needle diameter at 2mm   2.06mm            1.99mm

Good luck!
Jet needle diameter at 3mm   2.49mm              2.48mm
Jet needle diameter at 4mm   2.52mm              2.49mm
Jet needle diameter at 5mm   2.55mm              2.52mm