Polini Venturi Air Filter Induction Kit

[fredperrybruce]

Hi, was thinking about buying a venturi kit for the scoot and was wondering is it just a case of taking the rubber air bellow off and removing the original air filter and then attaching the venturi system to the carb box??

[Big Scotty]

There's a decent enough video that shows the fitting here,

[fredperrybruce]

cheers for the Video Big scotty,, just what I needed to see!! "time to buy"

[henri]

then upjet an try an find a way round a foam filter where theres dirt/oil/water n heat , wash it every month/500 miles an re-oil with the expensive polini filter foam oil ,
your better off getting the carb mouth venturi stack an keeping the hose n sticking a k&n type filter inside the frame where it can suck clean cool water/oil less air , tho if youve got a exhaust leak the polini foam does keep emissions down by recycling the gas leak,
so if ya on a buying spree can ya spraken duetch n did the guy in vid say what main jet increase the filter needs ,i'm only good at ordering beer n food n saying "my chainsaw is kaput" ,so i only caught a bit at the end where he might of mentioned jetting but not sure , H

[fredperrybruce]

Cheers H,,, by the looks of things you need to jet quite high with those Venturi intakes look like a'lot more jetting and plug chops coming up.

[vespasco]

He said the kit comes with a jet but you may need to buy more/different jets to try for your particular set up.
And also recommends to fit the foam filter as it vasty improves air flow.
I've often thought about buying/using one as im sure it will improve the performance but am reluctant as im not sure how much louder it will be and also wonder about the warm air from the cylinder altering things. Plus i like it as stock as possible.
Has anyone tried one of these venturi/vortex adapter with the stock chassis/airbox rubber hose?

[henri]

i havent but a mate has ,he settled on the set-up i described to fred , an with the side panel on the increase of intake noise wasnt really that noticable ,prob coz he's a "loud pipe" merchant ,
he ended up puttin hose back on an k&n filter as the foam kept getting really dirty ,an that was easier than fixing his oil n exhaust leaks , i instinctly distrust em as my experience of foams+oil/dirt+heat is that they age quickly an then unless great care is taken rip whilst washing/cleaning , an they are free-er flowing good filtering filters ,but where there placed they wud need to be to equal the stock set up ,H

[vespasco]

Ah! Now i see what you mean Henri...fit the foam filter inside the chassis!
In my mind i think that if i put a lump of foam in my air intake it would decrease the volume of free flowing air available for the new venturi adapter?!
Or is it that the adapter would suck air in faster and therefore making more air available?
I have only a single layer of gauge on my stock filter at the moment (trying to get as much air as poss).
If i were to fit a venturi adapter, keep the hose, and have no filter!!??
Or use just a very thin layer of foam under the seat or behind the air intake hole in the chassis, more to block debris than moisture, how do think that would work?
Do they do something like that nowadays on more modern/restricted scoots?
Do you think there would be more blowback if there is no filter inside the airbox?

[henri]

it was a k&n style cone filter stuck inside chassis as thats all we had when my hamfisted mate ripped the foam 1 whilst "cleaning/washing" it, the foam ones are free-er flowing coz theres more surface area of tiny holes than a stock 1, they still filter grit n dirt down to same size , the k&n copys are more open grill/mesh an pass more air but also larger dirt particles if any are present .thats why we fitted it inside chassis rather than on airbox .
the piaggio cosa had a secondary filter under the seat of foam an it cut down air so much a 125 runs a 83main rather than a px's 96, other modern auto's have secondary airboxes as part of the "semi-catalytic" system for emissions ,there not really filters but a one way valve to let air into exhaust to promote burning of exhausted unburnt fuel to keep emissions low an mostly on 4strokes.
an with no filter spit back amount will be the same ,just theres no filter to catch it an feed it back into the nxt charge of air,so it settles on airbox base where fuel evaporates n gets sucked in an oil just festers , i guess ,never run 1 or seen 1 run long enuff to judge , fraid in my opinion there just another "fairy dust" magic tuning option ,often bought coz theve a italian name n sip charge loads for em, experience n advice has learnt me theres no magic "extra speed" bought in a box ,or i'd have a shed-ful off em, i think the give away is sip saying they send "A"/1 jet with the kit ,an we both know in tunes theres no "1 size fits all" solution ,unless on checkout theve a tech/tuning expert askin a shed load of questions about ya engine , which carb/kit/exhaust ,inlet work,squish,porting etc , an even then he'll be guessin , H

[sbwnik]

They do work, when the original was created (These aren't they, but are identical - may have bought the designs?) there were dyno charts around showing the difference on a standard motor. It wasn't huge, but there was a difference.
This is about ten years ago though, early days of SBW when BBS in the US was still a reasonable read and not an advertising forum.