Forum

[Graham43]

Hi
I have fitted a free flowing exhaust and silencer to my Electra and looking to fit a S&B or similar filter but I thought why? I can see why a dry hot country, like India, needs a big car type pancake filter but none of my old bikes had filters. If mainly road riding in our damp weather special in NW England why do we need a DUST filter? Perhaps big singles with GP carbs need one to stop small children being sucked in and spoiling the settings but not for my mild Electra.
I have my helmet on ready for comments.

[PeteF]

Years ago we never bothered with them and some engines weren't even fitted with one.
Having said that I think you'd be surprised how much crap they catch.

[Chris [Stockport]]

Hi Graham,

I once rode through some roadworks in Manchester, dust flying all over from their drilling, I thought: I'd never put even a bit of that near my carb on purpose... so I don't want someone else shoving it in!!

Just my idea/ experience!

Regards, Chris

[STU]

Fair point Graham, and I think that Pete gives the answer. If you look in your airfiler after a few thousand miles you'll find dust, fluff, insects, bits of grit and general detritus - which would have otherwise entered your engine via carb, inlet valve, combustion chamber, crankcases etc.
In the interests of longevity and reliability I wouldn't want this crap in my engine, and so stick with KN sports filter in cut-down airbox on my Electra.
Your so called mild Electra Graham has a 30% higher CR than the old iron engine Enfields and with a reasonably big piston and long stroke would be pulling in (and pumping out past the exhaust valve via your extra free flowing exhaust) a significant amount of ambient air - complete with all that is suspended in it - into your engine!
As Pete says we never used to have filters on old Brit and Euro bikes - and put up with the carb wear, valve regrinds/seat replacements, little/big end wear etc... and then along came the Japs (also from the land of damp weather)with every UK-market bike supplied c/w airfiter in a chamber/box and guess what? Much more reliable and lower maintenance engines...
Perhaps I've got it all wrong, what other views are out there?

[Peter 53]

When the gauze on my bellmouth spat itself out, I ran it without any kind of filter for a while, then one day in a moment of inspiration I found that the cover from an SM58 microphone fits in the bellmouth nicely!

[Dennis C]

Graham

That's a good question, I have bikes with a filter, bikes without a filter and one bike that when new in 1955 the filter was an optional extra.

If you mostly ride the bike on clean dust free roads, a filter does very little, yes I know that the filter if fitted gets dirty but most of the dirt it stops does no damage whatsoever it just gets burnt and blown out the exhaust, if any does end up in the crankcase then you have a serious piston ring problem.

Having said that if the bike is designed to run with a filter why would you take it off?, it does some good and gives no adverse effect to the running of the bike.

[Craig]

Peter53 (can Not resist) We Use To Buy Them Cheap Chrome TEA STRAINERS and use the Middle or if on a Twin (Tea strainer Handles Bent In Ward) They Bolted On to the Carb Mount's..Some Looked Proper Good..(But we was young & Brit bikes where cheap in the 70's).....FILTERS: "Besides Keeping Out the Crap, I thought good tuning/Running is a Balance Between Air In (Filter) And air Out (Silencer)..Lastly Warning!: Back in Our Gerbo days,Me Mate Bens B31 (NO Filler & Bell Mouth) Spat Back & Set fire To his Origanals on the New M42... How we Laughed As He Went through the Hedge And rolled On the floor ;0)...

[Peter 53]

Craig that must've been really amusing - I've been through a few hedges in my time! I can picture those tea strainers from the pound shop as it goes, and why not?

[Phil Ashbrook]

In Sydney an air filter is a must and I should get in the habbit of oiling my filter for the dust but what I would fear most is road shrapnel , I wrecked a fresh 535cc bore with something hard and sharp that jumped in the carb at a well known crash zone ,I'm not taking risks with a new bore and last oversize forged piston , at a tiny cost in power it's worth it .

[Alan R]

Hi Guys------------ I'm with you, STU !!! The answer to this question is in the question itself ie to FILTER the air, of course..Just because a designer does or doesn't specify an item to be fitted on a product doesn't mean that we---the customer---have to slavishly obey and continue using that item without questioning that judgement..Dammit, it's OUR money after all....It's not rocket science really... Even you and I have an air filter up the old shnozzle !! ( No comments from me about the exhaust end !!)... Hello PETER 53 ----- with that microphone screen at one end and maybe a megaphone at the other ?? that must be a great sounding bike you have there ?? ... Full marks for ingenuity..... As for the tea strainers....they get used in the smokeboxes of model steam locomotives as a spark arrester--- a European dictate now !!