Modern Vespa

YESSSSS!!!!

I cán see behind in the mirror now

I'd take that mirror back to where you bought it, it's got a crack in it!

still gives a nice round view so a keeper I think

and anóther beheading

The charming company made sure of the Vespa theme

after last night´s celebration went at the larger volume filter housing lid again.
Drilled the hole for the idle speed adjustment, Have a fitting rubber.
Have the correct length M5 screws.
And.... cannot turn the screws. No space for the hexagonal heads, never mind a socket.
Right, round head slotted then. Another day, another go.
Even with the correct screws it will be fiddly because the holes do not really nicely align with the thread in the housing and the screws are longer.
Not looking forward to changing jets

^^^ I must have missed your original reference, are you talking about installing a T5 air filter on your P?

Thank you v oodoo.
No, not a different filter, just a lid with more volume.
Should have the correct screws today or tomorrow.
Meanwhile went to the drop off point (bookshop in next village up the road) on the bicycle. My large backpack to stow the package (fly-screen).
Stormy weather but dry so ideal to make life of the scoots easier and shed more weight.
Alas an old friend had sent me a HÉAVY box with motor magazines. Too much to carry so took only the one small box and left the fly-screen too. Need to go back to pick up the screws anyway. Then fingers crossed I can find the threaded holes with them

these should work

bit of faffing as the new rubber gasket is very .... rubbery. The fit under the chassis is véry tight; no contact but not much clearance either. Hope the lid will settle down a bit in the rubber. When the wheel moves up though, clearance increases.
Found the thread in the base just about immediately.
Anyway; it is on.

The Pinasco or Polini versions are more squarish in design. Pinasco claims 20% more volume. The Polini is a bit larger but no volume specified.
Mine No-Brand-Special is more voluminous still and has a rounded profile which suits very well imo.
Did not measure with fluid, just measured hight difference and that is between 60 and 130% higher. As the filter housing also has volume below the edge, the chamber volume increase is way less than the volume increase in the cover. Would still be about a 50 % increase in total volume.

Started as always, picks up at least as always. Sounds identical too; no increased intake noise.
That is without load though.

Don´t know if it will make any difference but I like the idea and it shoúld give a bit better initial throttle response. More immediate air flow will probably make the (smaller/richer) air jet more critical.

Jack221 can you continue with the ´idle jet´ instalment? I am véry anxious to fit a richer one as DREAD the throttle off seizure.

Where did we get to with the set up?

Still bog standard but fitting the Polini road box this weekend.
Will then redo the main jet drill you shared.

Filter has the heart drilled and now a larger volume cover. Weather permitting will do some drive about tomorrow morning but don´t expect the larger cover will cry for rejetting. But will adjust idle running if only to check if the mixture screw has fine or course thread.

Currently main jet 125, air 150. Was 116 and 160.

Next do a base line ´performance test´ on a stretch of ascending straight-ish road.

Plan is rejet for the Polini road, drive it some time, repeat above test.

Next fit the Megadella. Repeat.

Ride around and base line ´test´.

Hard/impossible? to explain/relate to the filter cover but... it vibrates less. Does not seem logical but no doubt about it.
As expected picks up better from standstill. Slow revs riding pick up ditto. Just responds better from idle/slow running. Thát I can explain.

Course thread idle mixture adjustment.

The stretch of road I picked for the base line is not ideal: A bit too steep for 4th really. The engine júst holds 80 km/h. It does make it a litmus test though. Nothing subjective about it influenced by sound if it does pull better with the Polini.

For ´honest´ top speed need to go elsewhere as there is no flat, straight road here. Can only observe that with 6"2 and 195 lbs. rider wearing a loose fit wind jacket it easily goes 100 km/h on the speedo on shortish bits.

I agree with Coddy. If you see that crack every time you look at the mirror it could distort your view....or maybe not

There is a different crack in the mirror of the red one

Some perspective:
- My old workshop is at the farm I moved out of and where my ex is residing.
My new place has some space but as I still have most vehicles and tools at the farm. Ergo it is sub ideal.
- My ówn personal original framework needed some upgrades and those work surprisingly well. Yet the rest of the frame is rather worse for wear too nor do the titanium bearings OEM functionality. Ergo rolling on the floor is sub ideal.

Proper down poor this evening so started on the exhaust.
Taking the fitted replica standard box off was minutes ´work´.
The Polini has no clamp so thought to swap the replica´s off.
Alas, that has a spot weld to keep it in place.
Looked at the Megadella and that does have a very nice removable clamp with neat custom bolt.
Alas, it will only fit the Polini if I bend it open quite far; limit of the bolt. Better not.
Thus skipping the Polini and go Megadella straight away.
Alas, the exhaust sleeve does not enter the pipe. No way José
Measures the same diameter though.
Turn the stub sleeve out to have literally more wiggling space.
It is just slight welding warp unroundness and paint: With alternately some winding it in and cleaning, it fits like a custom glove.
Meanwhile thunder & lightning, dog calling for me.
Will continue tomorrow.

First though, with morning coffee, check my jet kit and look for a richer idle jet to fit. Also will go 140 air and 130 on the main. Yes, will look what´s the biggest main I have.

Went relatively smooth.
The relative was the 10 mm screw at the bottom being not original and too short for the sliding captive nut of the Megadella. Did not have it here so had to get a 1 cm longer one.
Next it went ok.

Changed the jets too. The biggest challenge being réad the sizes
Added some ´lead´ with a pencil, used the zoon of the mobile camera and phew

Fitted 130 main, 140 air.
The idle jet was 50/160 and fitted a 60/160 so ratio from 3.2 to 2.66

Now first another coffee before starting up,

Starts as usual.
Appears same sound, but hey, cccccóld.

Pulls off stronger.
When nicely hot it pulls significantly better and maintains speed with less effort.
When riding the exhaust note is quieter, the engine appears to be working less hard. It shoúld rev noticeably more but at the moment does not.
When on the stand in neutral does not rev out cleanly.
In third same.
In fourth holds 10 km/h more up the incline though, despite not revving as well in third.

Noteworthy is that rolling slightly off the throttle ´brakes´ the engine. It hesitates slightly when opening again.

Idle is too rich. Need to screw the adjustment well down.
A bit apprehensive about that as the smallest I have is the 50/160 which was fitted and the smallest in the kit is 58. Will fit the latter.
Gone down to 128 for the main. Doubt it will be enough, went 140 air mind, but better too careful. (p.s. just remembered about the float passage )

So now:
128 main, 140 air
idle 58/160
and fingers x-ed

The Megadella has the same or more ground clearance than the replica original. Is higher though and the centre stand spring júst sort of clears the way fatter pipe; is free with stand in, just touches when on the stand.

Trivial detail: Do I add the stickers somewhere or not? For stickers they áre kinda cool.

so I had a senior moment
Forgot about the float passage, so in 130 is too large, then 125 will be same.
Ergo probably 140 air is overkill.

First trying it with the current jetting though. Mañana

Stuck one sticker on the cylinder cowl. Still but not advertising the exhaust change.

Right now lunch and then arty farty afternoon with charming company and a lady friend of ours.

As expected going 128 made nó difference wotsoevvah

Out the jet kits, reading glasses, camera zoom...
As the 128 was nominally 125 main with 140 air, swapped for 125 main, 150 air.
It is after all only a change to drilled filter, some more buffer volume and tuned box exhaust.
The former two are marginal and the latter is a better but still an nicely quiet box exhaust.

My apologies for sharing the tedious step by step. I am also (ab)using the thread as log book.

Wheeling it out for a spin in a moment...

Ran a lot better. 150 air is definitely better. Not revving out quite cleanly. Put a 122 in.

First topping up fuel though.

After all the faffing with the jetting and the larger cover.... ordered the VMC filter cover

The VMC cover has already arrived; thréé days

Fitted the VMC airbox.

piece of work.

The idle speed adjustment... not so much. Not at all actually.
I decided to keep the original one. Needed véry little modifying. It removes/fits easily and the screw is wayWAY easier to reach through the plug hole than the short GMC 3 mm Allen head screw. Because the plug hole is lower than on the GRP cover, it is easier than that too.

The countersunk M5x80 Allen screw is a pita because it sit high under the chassis. Only a marginal improvement on the M5x60 Philips screw of the black GRP box.
The other side is a doddle to fit, but that was the easier ide before too.
So yes on/off ís easier, but not by much.

Ah and I decided to fit the finer foam. It is not thát fine anyway.

For that countersunk M5x80 screw that sits so close to the frame, I got myself a long & thin driver with a socket at the end, and an M5 hex socket. If you lift the seat, you can then get at that screw at about, oh, maybe 10 degrees out from vertical. If you're careful, it doesn't strip the head. Way faster than fiddling with a regular Allen key in that space.

The VMC airbox looks great looking forward to hearing how it works.

Would a ball end Allen work better?

Probably, yes! Glad I thought of it

Use a socket to turn it in as much as possible with my fingers and then a ball end Allen key.

Have said fingers crossed for the thing working

To have the two for comparison:

Looking at it in hand and fitted, I think the flow/speed though bellows and air box is the same. This in contrary to the larger volume covers in which the speed will slow down.
In the VMC the bell mouth over the carburettor entry will then speed up the flow considerably. Hence probably the monniker ´Venturi´. Even though it is not, it sounds great and imo sort of deserves it because of the delta of the speed.


I wondered about the communication between the jets and the carb entry. It seems rather cramped and more so when looking at the custom of drilling the ´heart´ through into the filter.
I thínk/suspect that the pressure in the bell mouth, the carb opening is increased by the ´sudden´ smooth reduction in diameter of the air flow. The communication opening chosen probably achieves the desired balance between the pressure above the jets and the atomised fuel outlet at the slide.

Btw. I totally get why they designed to diminutive screw. It does not obstruct the flow whereas the original one literally sticks out and yes will have a ´negative´ effect. Negative between brackets because it is relative to the max possible improvement. The box will still improve flow considerably.
Will have a look if I have a rubber cap to replace the screw over the idle speed adjustment. - nope; not here, will have to get the box with assorted rubber/plastic thingamies from the farm.

Fitted a fast thingamy instead of the plug needing anóther Allen key.

Also used the radial grinder and file to mod the floating solo seat bracket for optimal air entry. Below is the ´original´ bracket.
(I have the not founded on evidence idea that the dual seat obstructs the flow more.)

As I thought to remove the filter foam also fitted a leave stopper; no helicopter seeds landing therein
The gauze is from the bell mouth of 1976 MotoGozzi LeMans 1. Thus for 35 bhp from 420 cc. Should be ok for my P200.

ok, took it out for a refill and a nice spin under the southern sun.

It runs like ...euhm... something which runs fast and light.
I nów get the observations I often read about the P200 having a long fourth: It blítzes in third to 90 km/h and fourth needs some help by wind or incline to start to sing too. Mind, I am 185 cm, 90 kg (clean on the hook) and had a largish, warm jacket on.

I think main jet/air is ok with 125/150.

Idle seems too rich now. Have the mixture screw out 270 degrees only and it hesitates on pick up.
Open to suggestions about test options before going down from the current 58/160 idle jet. Standard (at least what came out) was 50/160.
I need to order anyway as my kit goes up fróm 58, so 52/160 and 55/160 bút....
what I wonder about in particular is how you guys change from the standard 160 to 140 or 120.
Maybe need a 48(50,52?)/140
Dunno. Am reading that the VMC box flows most 1/4 to 3/4 throttle so maybe the larger 160 overlap is a góód thing?!
Happy to order a BE1 and/or BE6 (or BE5 as SC has 5 - 6 reverse from NSM) atomiser going one/two up from the standard BE3.

Anyway, for the moment the scoot runs and seems too rich at the low end and that makes me feel safe from throttle off seizing.

Have added some to the shopping basket.
DellOrto ones to avoid sizing confusion.

The intake is pretty much unrestricted with a bell mount and the exhaust is to all extends and purposes a tuned expansion one.

So:

Emulsion tube BE1 and BE6 (following NSM table)
Idle jets 55/160, 50/140 and 40/120.

Jack221 , oopsclunkthud , Voodoo , @all
Suggestion please before I order

What's your jetting now? And what issue is there?
Is there a rev counter on it?

Main/air is 125/150 (following your routine).
Emulsion BE3
Idle 58/160 (from 50/160)

Megadella exhaust box.
VMC airbox (no filter).

No rev counter.

Runs very well on main once revving. Both on stand and in 3rd revs cleanly out.
Idle mixture screw out only 270 (3/4 turn) degrees.
Idle settles very quickly and is stable as a rock.
Slightly bogs down on take off, flipping the throttle, when reopening throttle when riding (from under 1/4 throttle).
Could pull better from low/mid range.

I am hugely flattered, but I am a 'fraidy cat old fart scared to run anything but mostly stock or just a mild up jet w/ better exhaust on most of my stuff. It already goes faster than I dare regardless. Except my small frames where I have 'played around' some, but that doesn't help you.

I am watching & learning here like most of us, but maybe let's ask THE Chandlerman what HE thinks?


PAGING CHANDLERMAN!!!

Ordered some; all DellOrto:
Emulsion tubes BE1 and BE5.
Idle jets 55/160 and 45/140.

Redo the main jet with AC140/BE3 and the low rpm splutter will improve.

Then move onto the pilot jet. The small number of the pilot jet, when all else is correct, will not be less than 52 and unlikely to be more than 58 on your set up. no point doing anything with the pilot until the main jet is set.

Thank you. Will go 140 AC first then.

Further in the week will try a different pilot.

Will thén try a richer emulsion just for the heck of it.

btw in the simply mâhvellous wiki on jetting 4$ brass bits are mentioned. Make that 7-8€ now. Shipping cost gone same
Common post Bexit phenomena but still
To come back on the observation about penny wise, pounds foolish, unless you do more scoots, you like me will end up with some 150€ worth of brass bits unused in neat little boxes on the shelf. Mind; I wholeheartedly agree, but it is not exactly just 4$ no?!

No no NO! Buy them in a box of TEN for much less from lots of sources if you search. Here's one in England for £22.99 and I'm sure there are others in Europe.

https://www.vespajets.com/product/10-vespa-main-jets-for-dellorto-si-carbs-115-118-120-122-125-128-130-132-135-138-2/