Bell-mouth intake
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Tue Oct 26, 2010 9:20 am quote
HappyOne wrote:
Any plans for one for the ET4?
The ET4 has more issues with the intake than a simple bell could solve or improve. The only working substitution I know of is with a PWK carb.
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Wrench
Joined: 14 Sep 2010
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Tue Oct 26, 2010 1:13 pm quote
On that setup, did you do any crank cutting for the 100 kit? Rotary pad mods? or stock?

And on the intake.. Wow, just wow. Always kinda hated that stupid tin can, always went with the later 19/19's with a the plastic box sans filter or a Polini. Had no idea the bell could help that much.

I just bought 2 complete sets and a 20mm si. Now add some coin for you and get the Germans hip via the GSF. With all the mad profit you can buy all the Popeyes chicken you want!

And the old 19/19's with the studs just became hip again.
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Tue Oct 26, 2010 2:15 pm quote
On this one we didn't cut the crank or match any ports... Just bolted together. I really want to build a small flow bench now.

The 19/19 on the smallframe and the 20/20 on the large frame are really the only carbs where this can really help. both those carbs have a square edge into them.

I've been thinking of redesigning the one for the 19/19 so it can be used inside this polini filter.



http://www.scooterwest.com/items/?_pageCCS=t#page=/item_details/Polini-Air-filter-for-Small-Frame-19mm/1622
Ossessionato
1970 Vespa Rally 180
Joined: 04 Dec 2008
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Tue Oct 26, 2010 2:55 pm quote
oh man im so excited about this. i have a 20/20 on my rally 180. im assuming this would help? are there any other mods to be done to accomodate these?

anyway, ill wait till the bugs are worked then i will be getting one as well. cool cool cool
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Wrench
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Tue Oct 26, 2010 3:37 pm quote
[quote="oopsclunkthud"]I've been thinking of redesigning the one for the 19/19 so it can be used inside this polini filter.[/quote]

If it fit the later 19/19 type with the flange that would be quite cool to say the least.

And big thanks for the 50 info.. Major help there too..
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Sat Nov 06, 2010 12:20 pm quote
With the 19/19 carb I had to go up to a 110 main jet before it started bogging even a little. Working my way down from there now.
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Sat Nov 06, 2010 2:18 pm quote
oopsclunkthud wrote:
With the 19/19 carb I had to go up to a 110 main jet before it started bogging even a little. Working my way down from there now.
settled on a 108 main jet. This is on a 100cc kitted 50 special.
nothing at all
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Sat Nov 06, 2010 2:30 pm quote
oopsclunkthud wrote:
oopsclunkthud wrote:
With the 19/19 carb I had to go up to a 110 main jet before it started bogging even a little. Working my way down from there now.
settled on a 108 main jet. This is on a 100cc kitted 50 special.
with what pipe patrick

Last edited by jimmyb865 on Sun Nov 07, 2010 7:58 am; edited 1 time in total
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Sun Nov 07, 2010 7:46 am quote
jimmyb865 wrote:
oopsclunkthud wrote:
oopsclunkthud wrote:
With the 19/19 carb I had to go up to a 110 main jet before it started bogging even a little. Working my way down from there now.
settled on a 108 main jet. This is on a 100cc kitted 50 special.
with what pipe 'redacted'
The setup in this case is as follows:
50 Special crank, uncut (43mm)
pinasco 100 kit
22/63 Vespa 90 primary drive
4 plate clutch with stock spring
Dellorto 19/19 carb
Polini righthand exhaust
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Wrench
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Tue Nov 09, 2010 11:25 am quote
Well the Shapeways worldwide delivery team(they look just like UPS) showed up yesterday with my product.

The material is quite strong enough, sure the 19/19 ones will last basically forever baring any smashing up at install or removal. Fit and finish is almost mind boggling, just perfect, and the Epcot center look of the cap is funny.

And the timing is perfect on the 20/20 LF one. Just finishing a motor tonight that is a total rebuild with mild tune and will be perfect for some comparison testing. Won't really be able to press long and hard, but will be able to get some comparisons.





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Tue Nov 09, 2010 11:50 am quote
Professor Plum wrote:
And the timing is perfect on the 20/20 LF one. Just finishing a motor tonight that is a total rebuild with mild tune and will be perfect for some comparison testing. Won't really be able to press long and hard, but will be able to get some comparisons.
I have not jetted a largeframe with this yet, so go big and work down. Interested to hear the results.
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1974 Rally 200, 1974 Rally 200 with sidecar, 1966 Bluebadge, 2012 Stella 4T
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Mon Feb 14, 2011 8:48 pm quote
I ordered one for the 19/19 on my 50 special.

50 Special cases
ET3 primary
Cut crank
ET3 125cc top end
ET3 pipe
ET3 electronic ignition

....basically an almost stock ET3 set up other than the cut crank.

I went from a 76 main to an 85. The top speed isn't any greater (maybe 1 or 2 mph faster) but the acceleration is a lot snappier and no flat spots anywhere. I imagine the jet sizes will really jump on kitted, piped bikes if I had to 9 jets higher on something stock.

Nice job on this oopsclunkthud.
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Mon Feb 14, 2011 9:40 pm quote
I wondered who ordered one, I just get a notice that it's being shipped out to someone.

Glad it worked out I really like it on our 50 (102) special.
Ossessionato
1970 Vespa Rally 180
Joined: 04 Dec 2008
Posts: 4144
Location: Denton Tx.
Tue Feb 15, 2011 7:34 pm quote
any feed back on the jetting for the large frame?
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Wrench
Joined: 14 Sep 2010
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Wed Feb 16, 2011 11:52 am quote
jamesjohn wrote:
any feed back on the jetting for the large frame?
you run a 20/20 right? I had one on a 20/20 for some miles after a rebuild..

Maybe 40-50mi. of easy suburban riding(i ride fast though).. Man, the thing was jetted perfect, singing sweet.. Next day I went back to stock(blue stella type A/F with the white lining pulled out), no other changes.. Scoot was way rich and a little wet too..

Unit is right here if you want to test it.. Will PM details..
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1970 Vespa Rally 180
Joined: 04 Dec 2008
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Location: Denton Tx.
Wed Feb 16, 2011 12:37 pm quote
hell ya! i would love to test this! i have some jets waiting too. pm sending...
Molto Verboso
79 P200e, 81 100 Sport
Joined: 23 Sep 2006
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Location: Iowa
Tue Mar 08, 2011 7:43 am quote
The store is still open and these are good to go, correct?

I'll be ordering one of these for my wife's 100 Sport 19/19 in a week or so...
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Tue Mar 08, 2011 8:05 am quote
Yup, still open, still no markup.

http://www.shapeways.com/shops/oopsclunkthud
Molto Verboso
Joined: 24 Jan 2008
Posts: 1909
Location: Santa Margarita,Ca.
Tue Mar 08, 2011 8:33 am quote
Hey Patrick, do you have any xtra bubble covers on hand. I ordered the bells before you had the covers and haven't got around to ordering up the covers.
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Tue Mar 08, 2011 8:52 am quote
scootermarc69 wrote:
Hey Patrick, do you have any xtra bubble covers on hand. I ordered the bells before you had the covers and haven't got around to ordering up the covers.
Nope, only have the one on the bike.
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Sun Apr 03, 2011 12:18 pm quote
Given the number of Polini airfilters out there for the smallframe 19/19 carb, I've done a new design of the bell mouth.

This replaces the inner ring that the polini filter clamps to. This part of the polini kit is a hard plastic and I've seen several reports of it breaking as well as issues with the filter not getting a good grip on it.

This replacement has a serrated outer edge to help the filter clamp on better as well as having the same elliptical bell as used on the other design.

http://www.shapeways.com/model/235049/

I have not verified the fit yet but given it's based on an existing design everything should fit just right.

Screen shot 2011-04-03 at 13.07.33 .jpg

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Mon Apr 18, 2011 10:49 am quote
Got the new bell in the mail today, probably be installing on a malossi 135 this weekend.

IMG_2682.jpg

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'60 VS5, '63 Li 150 Special, '07 PX125
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Sun May 01, 2011 7:54 am quote
Hey Patrick, or anyone else who has tried the 20/20 bellmouth...

I got one of these to try but am wondering... What screws are you using to hold this thing down? I guess I can use the original tall screw in the back, but the front hole is obscured by the bellmouth. Maybe some kinda narrow allen head screw? Any tips on what works before I embark on a quest for fasteners?
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Wrench
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Sun May 01, 2011 9:13 am quote
I ground down the circumference of a cheese head slotted screw for the one in the bell.. And the one outside I used a bolt..

Remember it's only 1/2 oz of plastic, tighten lightly and maybe with a dab of something sticky one that inner one..

I think I had to do a tiny bit of file type(very delicate dremel) work as well, clearance on them is nice and tight..
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Sun May 01, 2011 6:59 pm quote
for the bolt that goes through the side of the bell at the back, the stock screw works well. The one that is at the front can take an allen or button head screw. Best to put the allen head through before placing it on the carb as that allows it to flex a bit to get around the bell.

They are designed to be snug so that things don't come apart while riding but a bit of blue loctite would be good as well.
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07 Stella, 65 VBB
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Tue May 03, 2011 4:50 pm quote
Just trying to figure this out, the bell replaces the air filter, correct? If so, would it be wise to go Uni filter at the same time? Also, is there a consensus about how this affects performance and jetting? Cheers!
Ossessionato
1970 Vespa Rally 180
Joined: 04 Dec 2008
Posts: 4144
Location: Denton Tx.
Tue May 03, 2011 4:55 pm quote
no filter can be attached.

and yea, you gotta upjet. not sure how much yet, but i will be doing testing soon on a 20/20. and i will be posting on this thread as soon as possible.
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07 Stella, 65 VBB
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Tue May 03, 2011 5:04 pm quote
jamesjohn wrote:
no filter can be attached.
That is why I am thinking a Uni, although it would be messy as Hell. Thanks for being a test subject!
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'78 Super 150 Mk II ported DR177, banded clutch, ASC Big Bore
Joined: 14 Jul 2008
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Mon May 23, 2011 7:37 pm quote
Very, very seriously thinking about this. I had an air-leak from the spark plug the other day and liked the performance...

My only concern is a lack of an air filter. I run my airbox without the rubber plug on the back for the mix screw. That means some real dirt can get in... I'd hate for it to make its way to the engine...

Oopsclunkthud -- does the airbox cover still fit on over the bellmouth intake? If so I could close the plug and put a screen over the bellow to at least trap some particulates...
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Mon May 23, 2011 8:23 pm quote
On a 20mm carb the cover will fit over the bell and allow enough airflow around it. Yes there is no filter but if all the rubber bits are in place on the carb box including the bellows then the air travels a long slow path from under the seat in to the frame through the bellows to the carb box and finally down into the bell. The volume inside the frame forms a rather large plenum allowing any sizable debris to fall out. Even in the carb box the air velocity is very low.

Is there a risk, sure. I don't think it's a very large one and feel fine running an open bell on a few of my bikes. You'll have to decide for yourself though. Also, you MUST rejet with the bell.
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LX50, T5 Classic
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Mon May 23, 2011 9:32 pm quote
Hello
Would this mod be possile on a T5? (24/24 carb right?) If so would it even make any different?

All the best
Jake
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Wrench
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Tue May 24, 2011 12:45 am quote
About the 20/20 and the cover clearance..

I think it clears fine, but for extra piece and ease of mind I use these:

http://www.scootermercato.com/Scooter-Parts/Gaskets_2/239049

This is a original piaggio part, and is 1 piece and as fat a gasket as you could run.. Lifts the cover 2-4mm depending on the current type..

Just a tip, not so needed, but if you hate fighting with reinstalling a oily string of box gasket every time you pull cover, try it
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Tue May 24, 2011 6:06 am quote
pqhf5kd wrote:
Hello
Would this mod be possile on a T5? (24/24 carb right?) If so would it even make any different?
The size of the bell has to scale with the carb size and I'm not sure that it can be made to fit inside the carb box with the 24. I am looking at it but there are many things higher on my priorities.

Also with the 24 there is the option of the Vortex.
Molto Verboso
Joined: 24 Jan 2008
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Location: Santa Margarita,Ca.
Tue May 24, 2011 11:13 am quote
The T5 air filter has a funnel shape in the bottom plate. Probably not as optimised as Patricks.
Member
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Thu Oct 11, 2012 10:29 am quote
for the 19/19 smallframe version of the bellmouth, has anyone put a uni or K&N etc filter on it? I don't want to run it without a filter. 2.5 inch diameter on the collar intended for the Polini version filter. The Polini looks too restrictive.
Hooked
Stella
Joined: 24 Aug 2012
Posts: 272
Location: Tampa, FL
Thu Oct 11, 2012 11:05 am quote
I like this A LOT. Especially for stock Stella filters which are incredibly restricted, this could make a huge improvement for a small price. Way to go! Awesome stuff. I'll be watching closely for updates on 20/20 carbs.
Molto Verboso
Joined: 24 Jan 2008
Posts: 1909
Location: Santa Margarita,Ca.
Thu Oct 11, 2012 11:35 am quote
jambretta wrote:
for the 19/19 smallframe version of the bellmouth, has anyone put a uni or K&N etc filter on it? I don't want to run it without a filter. 2.5 inch diameter on the collar intended for the Polini version filter. The Polini looks too restrictive.
I have aan early version pre filter flange and use a 2 3/4" uni pod over the whole thing, clamped to the carb. I'd guess the flange versions would work well with the uni pancake motorsport sells
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Thu Oct 11, 2012 11:58 am quote
the flange on the bell is 62mm (2.44in).

The polini has room at the intake for 5 holes with only two drilled on some versions. The nice thing about the polini is that it's got a good plenum volume while still fitting inside the body.
Veni, Vidi, Posti
74 50s x3 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
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Location: seattle/athens
Thu Oct 11, 2012 5:41 pm quote
I don't like the Polini so-called 'filter'. I bought one and discovered it's just an intake elbow.
From the Scooterwest website:
Quote:
Polini air box for 19mm small frame carburators. This one of the best things you can do to get a little more out of your stock or lightly tuned small frame. MAKE SURE TO UP JET. Contains no air filter material.


I found this filter at O'Reilly's(on the right) and it clamps well on my 20L DelOrto which has the same size ~2 1/2" clamp ring and bike runs great with it.
You can see the 20L already has a small bellmouth .

Lurker
Joined: 04 Feb 2014
Posts: 4

Tue Feb 04, 2014 12:31 pm quote
i dont know how far along you are with these, looks like its been a long time since anyone has posted

just wondered if there is one available to fit a later type 19/19 on a pk?
if so how would i go about getting hold of one? (that is if i still can?)

thanks
tony
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