Bell-mouth intake
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Joined: 11 Jan 2007
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Location: San Francisco
Sat Apr 08, 2017 8:27 pm quote
It' not hard to machine in a step, but then you also have the manufacturing variability of the carb. If it was the same level then flat is flat. Looks like only a mm or 2 max, I may order one and see if I can mill it down.

I can't take credit for the replaceable seat idea, was mentioned in another thread around here. Shocked it's still not been done.
Hooked
Vespa PX200
Joined: 27 Jun 2010
Posts: 372
Location: Belgrade
Sun May 21, 2017 1:20 pm quote
Just bumping this thread up again, on the subject of alternate ways to have a bellmouth intake on the carb *and* have air filtration *and* keep the air bellow. Bonus points for simplicity, and ease of cleaning.

Here's what I've come up with -- see attached.

See, I found a bunch of filters for old velocity stacks that might just snap on to the PX air box. (57-58mm diameter or thereabouts.) Then, so goes my thinking, the air bellow could be stretched over top of that, and bob's your uncle.

http://www.carburetion.com/Products/ProductDetails.aspx?part=CUSF57LP

http://www.mikunioz.com/shop/velocity-stack-with-gauze-fits-carburetor-spigot-58mm-thru-62mm/

https://www.merlinmotorsport.co.uk/p/weber-40-dcoe-mesh-ram-pipe-filters-pair-afm4056

http://www.bisonmotorsports.com/Push-In-Microphone-Filter-for-Bison-Motorsports-Ve-p/00-0057.htm

Whaddya think?

filtration.png

Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7051
Location: Victoria, Australia
Mon May 22, 2017 2:44 pm quote
I have plenty of trouble getting the bellows over the carb box lip as it is (unless I do that end first, and then the trouble is at the other end!) so I'm not sure how well that would work... it could be fitted inside the hole (50mm diameter). But you still end up with a kind of non-filtering filter...

I like what a friend did on his. Just needs some kind of plate to keep it in place (2nd pic) - and a good tank removal/replacement technique!

David filter 1.jpg

David filter 2.jpg

Hooked
Vespa PX200
Joined: 27 Jun 2010
Posts: 372
Location: Belgrade
Mon May 22, 2017 11:35 pm quote
@ginch -- yeah, I saw that one, and it's ingenious, but it looks like a bitch to clean (as you point out.) I wouldn't want to have to pull the tank every time.

"But you still end up with a kind of non-filtering filter... " -- what do you mean? A few of of these filters have a *lot* of mesh to them. More than what's on the stock air filter, at any rate.
Molto Verboso
1979 P150X, 1983 P200E, 1987 T5, 1996 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 1592
Location: Veria, Greece
Mon May 22, 2017 11:40 pm quote
Have you seen the "Dumbo" from MRP??

https://www.mrp-racing.de/Air-hose-adapter-50mm-DUMBO-Vespa-PX-T5-Sprint-Rally-VNB
Hooked
Vespa PX200
Joined: 27 Jun 2010
Posts: 372
Location: Belgrade
Mon May 22, 2017 11:52 pm quote
I haven't, but that's fascinating.

What does it achieve, other than allowing other air bellows to be clamped to the frame?

Maybe an inline filter could be installed on the end of it? Given the different clamping mechanism that would get around the trickiness of squeezing the stock air bellow over it.

EDIT: I see now that this Jumbo doodad was in answer to Ginch's question about having a secure mount for that polini foam filter mounted on the inside of the frame.
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7051
Location: Victoria, Australia
Tue May 23, 2017 2:08 am quote
That Dumbo thing is a bit strange... looks like too much hardware for the issue at hand.
I wonder if you could find or make a conical-shaped foam filter that clips in to the body hole from outside?
Molto Verboso
1979 P150X, 1983 P200E, 1987 T5, 1996 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 1592
Location: Veria, Greece
Tue May 23, 2017 2:41 am quote
I think a flat foam filter between the 2 plates would do the trick and it would be easy to clean...
Banned
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Joined: 11 Jan 2007
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Location: San Francisco
Tue May 23, 2017 4:56 am quote
I considered fitting a filter at the opening under the seat, still think that could be a good idea.
Hooked
Vespa PX200
Joined: 27 Jun 2010
Posts: 372
Location: Belgrade
Tue May 23, 2017 5:42 am quote
@oopsclunkthud -- me too. I bought that LML filter that goes in the hole there, but it looks very restrictive. And I've heard from more than one person that that's the case. The other thing that's worrying about relying on the underseat filter is that there are some holes elsewhere in the frame where dust and crap can sneak in, specifically the slots for the sidepanel latches.

Got a question here about the flow of air however, if I do try putting a filter at the opening of the airbox. Considering the whole point of this exercise is to maximize the efficiency of the bellmouth intake on the carb, would it not make sense to put the filtration as far from the business end as possible (i.e. in the frame)? Or am I thinking too much?
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Tue May 23, 2017 5:59 pm quote
JimVanMorrissey wrote:
would it not make sense to put the filtration as far from the business end as possible (i.e. in the frame)?
Yup, the further it is away the larger the plenum volume, but the more opportunity for other dirt to find its way in. That's where I was trying to get a good balance with the filter at the gasket layer of the air box. also considered a tapered cone shape filter inside the bellows.
Hooked
Vespa P200, Primavera 130, VNA200, Italjet Pack-a-Way Moped, Ciao etc
Joined: 24 Oct 2014
Posts: 323
Location: Humboldt County, California
Sun Apr 15, 2018 5:17 pm quote
Patrick...STL File?
Patrick,

Any chance you have an STL file of the 24 velocity stack I could try out? I'm at my brothers house with a 3D printer.

I don't remember if this is a business for you. If it is, sorry for the ask.

Dave Reed
Slugrockets SC
Addicted
1966 SS180,1968 Sprint, 72' Rally ,74 V90, '64 GL 150 & too many projects!
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Posts: 988
Location: seattle, wa
Sun Apr 15, 2018 11:01 pm quote
Unless you are driving on dirt - don't you think the air coming from the frame is relatively clean ? DO you think a filter is really necessary ? I dont bother on one scoot and seems find over a year later...

I think any particle that could really cause damage is too heavy to make it into the carb. In all the twists and turns on the way there it will precipitate out. The light fluffy stuff that makes it just get s incinerated. I have NOT seen any evidence of much (any at all really ) dirt making it there in the hose near the carb.
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Joined: 11 Jan 2007
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Location: San Francisco
Mon Apr 16, 2018 6:18 am quote
Re: Patrick...STL File?
email sent regarding the stl file.

I ran the filter in addition to the stock filter last year on the Melee and took the bike on several dirt roads. I did see a good bit of dust from the back of the carb box where I didn't have the rubber plug over the idle mix screw. Saw no evidence of dirt making its way through the frame to the air box.

The filter is still not a bad idea but not convinced it's really needed.
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Thu Dec 06, 2018 9:29 am quote
another alternative for the 19mm

Screen Shot 2018-12-06 at 09.26.55 .png

Banned
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Thu Aug 15, 2019 8:14 pm quote
adding the template for the large frame filter

24mmFilter.pdf
 Description:

Download
 Filename:  24mmFilter.pdf
 Filesize:  113.97 KB

Hooked
Ď64 V90 survivor, Ď75 V90 graffiti
Joined: 30 May 2018
Posts: 178
Location: Madison WI
Fri Aug 16, 2019 4:16 am quote
Have about 200 miles on my rebuilt V90 motor with Pinasco crank and 100 Sport top end.
19/19 with 80 main, 42 idle, 60 choke and air screw 1 Ĺ turns out. Proma pipe. Uni 4245 filter. Filter has a spring inside so it fits the limited space in the frame.
Started with an 82 main but couldnít get it running right between ľ and ĺ throttle.
Now pulls well thru the whole range. Plug looks good.

3F816E88-F513-4F91-ABD3-29A879075D89.jpeg

8F9B4310-B49E-4579-8D3C-073769E83EE9.jpeg

6D0E4951-1A9A-4898-9F1A-0FE086739F84.jpeg



Last edited by exmayor on Fri Aug 16, 2019 7:44 am; edited 1 time in total
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3819
Location: Millbin, Ostrayleea, mate
Fri Aug 16, 2019 7:13 am quote
Why even keep the air cleaner box?
After over 5yr of overheating struggles with Speedy, Ive decided its about time to consider taking other drastic measures... & taking off the PHBH28 !!

Being me, there no chance I'll (as of yet) just go & get the simple option of a 24/24, and as Ive got a kinda-26/26 (so Ginchi says... "its not really 26mm!"), plus i may be able to find/build a 27/23 off a SS180.
This got me a thunkin; i see that Patrick has made a cool foam filter which fits into the base of the box (so the original air cleaner box & flexi hose that goes into/under the fuel tank), BUT thinking about it (too much) the current setup on Speedy is simply an elbow bolted to engine case & hose to the PHBH, with home-sewn high-flow filter, & it works, then what's the use/point/justification of the air cleaner box? I'll be fitting a vortex or bellmouh to it, & it's likely that would be higher than the cover, so it would be sticking out anyway.
There is no auto-lube , so no channels in the cases, just a goddam big hole thru the cases..

YES, I've used the SEARCH function & still can't find references to not using an air cleaner box, but using a SI carb...
what am i not considering?
What have i missed?
Why does noone appear to be doing this (what i considered simple & obvious) mod?
Theres not even a "need" to make up some fancy adaptor plate if using a SI, its more jist getting out ol' trusty Master Grinder & cutting off everything besides the mounting area.

Ohh... does anyone know what is required to fit the 27/23?
There are 3 bolts to hold it down, so some redrilling/cutting/modification will be required.. (do i REALLY want to cut up a SS carb, just to see if it will work though?)
Another somewhat obvious mod that noone seems to do.

461E31F4-C431-43F0-94F7-B65888F59EC3.jpeg
Base of SS180 27/23

4A3DD144-90F5-451F-8ACD-C12322A1B861.jpeg
Need mounting point & bolt locators ...
Plus he mounts for cables would be handy

3B2DB9FD-FD61-4625-B1D9-4063838F4520.jpeg
Not a lot is of any (apparent) use

9A18443B-0721-496E-9E95-20928BC4D51F.jpeg
Why can't this simply be bolted to cases?

02F4DA5F-6D98-4616-9617-EC8DE34A8F7D.jpeg
Theres not really a lot that needs to be sealed!

F9A789A9-94AF-4661-9B56-BD69EB520574.jpeg
Currently this is whats on there, no flash or tricky things to seal

Banned
2:6
Joined: 11 Jan 2007
Posts: 7460
Location: San Francisco
Fri Aug 16, 2019 11:54 am quote
way back I cut down an airbox to keep the oil injection and fited the manifold you have now on top of that and then a phbh.


but more to the point, cutting the airbox to keep only the cable and base would be easy. could maybe find/make/modify the carb to take the cable directly, lowering the carb by ~5mm.

Then an airbox could be mounted on top of the carb with lots of room and a bell, and fed from the frame. Then a filter leading into the frame would keep it all clean. all very GS/SS like
Ossessionato
1976 Super (x 2), 1974 Primavera (x 2), 2006 Fly 150
Joined: 26 Sep 2013
Posts: 4874
Location: So Cal
Fri Aug 16, 2019 12:48 pm quote
If you donít have an oil pump, the carb box does seem to take up a lot of unnecessary space.

Iím guessing the original design intent behind having the carburetor enclosed in its own little housing may have been (1) to keep the noise down, (2) to keep it from slobbering 2T all over the place, and (3) to feed the carb cooler air from inside the frame. The last was probably the main issue.

Plenty of people run carbs with different filters. I say give it a go without the box. Whatís the worst that could happen?
Addicted
Joined: 26 Jan 2019
Posts: 642
Location: california
Sat Aug 17, 2019 12:02 am quote
I've been pondering a similar move.
Use base of airbox carved out for base.
Then create an airbag that gives the bellmouth plenty of space.

I have two ideas i've been pondering.
One was to use a GS airbag (report - settle down y'all).
I love the large mouth on these.
Polished aluminum looks so nice as well.

But at $130, for a non aluminum painted one, it seems like a lot to go hacking on.

So I have a second concept.
Havent sorted all the details but it is simpler and would also have a classic appeal.

Haven't fully worked it out - but you get the concept.

Screen Shot 2019-08-17 at 12.52.09 AM.jpg
Use a large rubber grommet so it fits on OD of bell mouth. snug fit means no bolts - just press fit on and off to adjust - much quicker and feels solid

Screen Shot 2019-08-17 at 12.56.56 AM.jpg
Aftermarket bellows or could use a PBH style if you prefer

Screen Shot 2019-08-17 at 12.59.51 AM.jpg
Gromit with shoulder could be bonded in to aluminum elbow. Then fit snuggly on to bell mouth. Might need to combine hose clamp to make it secure

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