Modern Vespa

I'm sure this has been hashed out many, many times in the past, but currently for 2017 (almost 2018), what is a nice touring cylinder for the Smallframe? I have a PK125xl. Currently it's all stock (except for a DRT short 4th). The engine is the desirable VMX5M case.
I haven't kept up on the smallframe tech, so i don't know what my tuning options are. What i would like out of my smallframe is for it to be as quick and have about the same amount of torque as my stock P200. I'd like to be able to cruise around at a true 60-65mph, and maybe hit 70mph on a little bit of a downhill. I have lots of hills and headwinds that i have to deal with where i live, so i would want the torque too. I'm NOT after a "screamer" whatsoever...just a solid higher speed torquey smallframe.

Which cylinder?
What clutch should i take a look at?
Will i need to get a different crank, or can i use my existing one?
Will i need to change my gearing?
What size carb? (i'd prefer to not cut the frame to fit a big carb)
What is the fuel economy of a tuned smallframe compared to a stock P2?
Which muffler or pipe?

I'm not wanting super expensive exotic parts...i'm after reliability, and a lower maintenance cylinder kit.

I've had the PK for about 7-8 years and really like it, but it doesn't have enough speed to cruise on the same highways that i commute on with my P2.

Building a torque-y smallie that can cruise reliably at 65mph will take a pretty good chunk of change. What's your budget?

I haven't set a budget yet since i have no idea what it would cost. I do tend to invest more dollars into quality components, rather than buy second best parts. From my understanding, one of the more difficult things to make reliable in a tuned smallframe is the clutch...and fancy clutches aren't cheap.
Perhaps my goals are too high? I'd even be OK with cruising 60mph reliably, rather than 65mph, if that's going to save me an extra $1000. I have a few other scoot projects that want attention as well, so i need to "spread the wealth" around a bit so no one gets jealous.

The key to getting torque out of the smallframe is really in the long stroke and rod. I'm running a DRT 53/105 on a Polini Race cylinder, TM24 carb and PM40 exhaust, DRT short 4th, 28/69 primary with Crimaz CM easy clutch. I'd say it's roughly the equivalent of a p200 but way more fun.

I second this. The 54mm crank really seems the go if your looking for more low rpm power. The guys at pipe designs have a variety of exhaust build around touring small frames. They say their exhausts were build with the Malossi 136 MK II / 54mm crank in mind. The dyno below is convincing.

Do you plan to strip the cases and rebuild or slap stuff on? Budget around 1k...?

I'll for sure strip down the cases. I'd want to go though everything and make sure the gears and shifter don't have any nicks in them. I'll also want to replace bearings and seals too.
I'd love to do it for only a $1000 budget, but I don't see doing it for that cheap. Maybe I could get away with closer to a $1500 build?

With a stock P200 around 11ft/lbs of torque and 10hp, maybe I'd be fine with a smallframe engine that produces the same amount of power? Or will a 10hp smallframe not go 65mph? I have no desire to have a smallframe engine that can wind over 7000rpms. I have a T5 racer, and one super fast scoot is enough for me. The rest of them are conservatively tuned or stock.

So according to the gearing calculator I use, with a 90/90-10 tire I am at 63mph/7K, 72mph/8K. The bike will only push 8K under very favorable conditions and much over that(8400), it stops turning, in a bad way. But it always starts back up and seems none the worse for wear.

I'm planning on trying this VMC kit from Italy on sale now under $200. I have no idea how it compares to the 'hi end' kits yet, but I'm not looking for a real big power increase.
I will add a 24 carb & a pipe but leave stock ignition, gears & clutch for now. I will need to have the cases welded before matching those ports and you probably will as well to hit the goals you've set.

Anybody here run one of these Pro Cup setups? https://www.avotecnica.com/cilindro-e-pistone-pro-cup-3-con-testa-in-alluminio-nicasil-vespa-et3-56mm-p-1292.html

Read that kit is a Quattrini M1 copy. If that helps at all.

Below is a port map of an M1L.
You could compare them.

http://medias.scooter-center.com/portmaps/8000068.jpg

So looking at the SIP website, there's a few different options for the Polini 130 cylinder kit. I don't think I'm interested in the Worb5 mods. I think the one I'm after is the standard cylinder kit that comes with the newer style cylinder head that has the additional cooling fins.
If I decide to stay with the stock length crankshaft, what should I expect from the cylinder power wise, and a cruising speed? I know that all depends upon gearing, pipe, and carb. I'm not after a "peaky" race pipe, nor am I interested in cramming on a 50mil carb (maybe a 24mil?). The long stroke sounds very interesting, but I'd rather not deal with more variables, such as packers, port timings, additional milling. I'm very familiar with gearing for largeframes, but when it comes to smallframes, I have no idea what to go after for different engine tunes.
The things that I'd love some advise on just which parts to go after for my PK125XL are -
-crank
-gearing
-clutch
-ignition (probably a vespatronic)
-carb size (prefer an easy to jet carb)
-exhaust (I'd prefer a touring exhaust, and ones that leaves access for the rear tire.
-other stuff that I'm forgetting...such as, do I need to buy a new carb intake?

I am on the road as you. And fooling around with my toughts of what cylinder to use.
Have no idea on the smallframe world,
Only drive T5's
Gonna start a pinasco t5 build soon.
But little eager to get the smallframe up and runing😈

I see that parmakit now have a 130 tourer kit on sip.

For me iam lokking at cylinder rotary intake
Polini 130- iron
Pinasco 135 alloy
Quattrini 144.

Or direct intake( leaning more To this)

Malossi 136- iron
Malossi 136 mhr- alloy
Parmakit 130 challenger.
Pinasco 135 alloy
Reason to go direct for me is less dremling on the engine case.

Rest: stock gearing( spanish primavera 125 4gears)
Thinking polini cp carb, since i have that for the t5 with all jets and needles ect..
Pinasco flytech
Bgm clutch
Crank mazzuelli rotary or
Crank drt full circle
Exhaust have no Clue but something vsp road ish or maby sip road depends on the cylinder and have to fit toolbox on the side.

Does any have anything to say why I should go rotary instead of direct intake( both reed)
Or go mad with the new pinasco engine case.

I'm in the process of putting the Pinasco top end on my Smallframe. https://blog.scooter-center.com/en/cylinder-pinasco-zuera-ss-135cc-vespa-smallframe/
It looks to be good quality. I also upgraded the ignition, carb, crank, and clutch.
I think I've spent around $1400

Vpfalcon that cylinder is nice.
thinking on the same sylinder on mine.
what carb are u gonna use? and set up?

but is this for race or is it road friendly?

Using Dellorto 24mm carb, I ride my scooters to work, and I go to rallies. Not looking to race it.

Same here looking for somthing fun everyday use, and stil make a nice tourer.

Thinking to use polini 24 or 26 mm
But have not decided to go rotary or cylinder intake, read somwhere on the interweb that rotary intake is better at low down tourq.

I see that the polini iron is highly loved by tourers,
But wanna try somthing alloy fun
And an exhaust that is not a high rpm monster.

On sip most exhaust that they say are made road friendly have exhaust timing around 180'


Lth road and midrange or vsp road.
See that malossi are making a banana and same for BGM banana. Nice tourq and not screamers.

I have a PK125 too, and I am really curious what will be your outcome. Speeding even less (you desired speed is 65mph/100kph) at around 80kph I feel like I am literally going to die and I ride much faster bikes regularly.. I think the frame and suspension is capable just of what it can do on stock, but good luck finding the best components... I would go with some aftermarket suspension along with engine upgrades. It really makes a difference.

Does that Pinasco cylinder you got have a 125* transfers / 185* exhaust duration?

I have to say I'm not sure what that means, but yes it is 125/185.

The original front and rear shocks are still on the bike, but they must be in excellent shape because my PK feels super stable at 50+ MPH...even with a BMX strapped to the rear rack. Even though it feels rock solid now, I'd probably still install a aftermarket front shock (possibly a rear as well). I'll go with a full hydro Grimeca disc as well since it would be fairly easy to install on the PK XL fork.

Ha, I can't tell if your joking? So, those numbers 125/185 are the port durations. That tells you when the cylinder makes its power and characteristics of the ride you will have.

A cylinder that has those port durations would be considered by most to be "peaky" or a "racer". You will experience a flat spot then hit a power band. Depending on which Simonini exhaust you chose (there are different versions) it could be very dramatic with very little power at lower rpms. Certain exhausts are know to soften this effect like the PM40 and they are often referred to as "touring" exhausts because of that.

It's a little confusing to read about people wanting to "tour" and "not wanting to race" but recommending this Pinasco cylinder kit. It's more aggressive on paper than the Polini mono, Malossi iron and the M1.

PureDrivenSnow thanx for the information.

when i look at most alloy cylinders i seems like they are all peaky monsters.
and thinking maby the good old iron cast cylinder wil do. for what i want.
but inner voice tells, that i should go for an alloy cylinder.

(Had som bad luck with iron cylinders on my large frame.
and little paranoid

a friend drives the polini 130 iron with match ports reed and open crank inlet
and polini snail exhaust dellorto 24or25mm
and it's good tourer and fast.
but how is the malossi iron compared?

If your friend has a proven set up that you've ridden and like, you might consider just going with that. There are a lot of variables involved in building a tuned engine from scratch, and the odds of it performing exactly how you hope or expect right out of the chocks are pretty slim. Just a little dose of reality... be prepared to devote some time and/or money tweaking a "custom" build. Just my two cents.

The Malossi iron kit is what I have. I drove my friends smallie with a Polini 130, 19/19, banana exhaust and wanted more power. The Malossi offers that. It's the kind of kit you can run a banana exhaust on it stock or raise the exhaust and run an expansion chamber. The transfers are high enough out of the box (125*) that you don't need to lift the barrel with packers.

If money wasn't an issue I would get the 144cc M1-L. I have no experience with it but it gets great feedback online and is still a "touring" cylinder.

Reed or rotary is sort of a personal choice. Myself and people I know on rotary have spitback issues. Reed seems to sort that out by design.

This is great advice. Uncharted waters in tuning can be confusing and expensive.

Yeah I know. His build has been bullet proof.
But I always wanna try something else.

I know that same tuning and build Wil be different from scooter to scooter.
Have always been driven Vespa T5 scooter especially and have 3 now and 2 with same engine build but totally different.

Had a quick look at the m1 60 rotary intake
Seems more friendly. But have to rebuild the engine and then se what money are left.
But the reality telling me it gonna be an polini 🤔

Sorry, messed that post up, tried to quote.

You got it. The key is making sure the exhaust plays well with the port timings of your cylinder. Might be worth seeing which exhaust you have and what it's intended for. There are several versions of that exhaust available now. If it does you'll be hauling ass in no time!

Right, if you want anything close to real performance you're going to have to forget about anything keeping the addition of a spare wheel under the panel or the like. However, the standard PK system works reasonably well and can be better with a freeflow elbow off the barrel.


I'd forget about getting too exotic here, Polini, Malossi, Parmakit, Pinasco, Quattrini etc. will all work to a degree but not ideal. In this instance I'd go cast iron new style Polini with new style cylinder head, SIP stainless steel free flow exhaust elbow on standard exhaust, standard gearing with a Surflex 3 plate clutch kit and Polini spring and a 24 or 25 mm carb and manifold.

You should be looking at around 11hp+ there and topping out around 60 to 65 mph in real life depending on your size, enough for most.

Looking through your posts you have the old style small pivot fork, these can be improved to a degree but you will be far better off fitting the PK80/125 type fork and hub.

Thanks for the non "exotic" recommendation. That might be the route that i will go. Not because of cost (though not having to spend a lot is always nice), but because i'm not after a high power engine on this particular scoot.

How beneficial would a Vespatronic be with just a plain old Polini 130 kit? Also, does a 54mm stroke crank work well with the cast iron Poilini 130, or is it not needed? Do they even make a 54mm stroke crank for rotary induction? Will the 54mm crank fit into the engine cases without any additional milling?

There are guys on here with more experience who will hopefully chime in. But my understanding is you have to mill the cases a little. All the 54mm cranks I see are all full circle. The cheapest cylinder that is often used is the Malossi 136 for this. Stroking it is going to shorten the transfer durations... the Malossi are already long... win/win? Could be good for a road tune.

Thanks, I did not know that. I just changed suspension for a brand new shock absorbers, and I am really looking forward to see some improvements.

I remember a few years ago Scootering magazine did a built up a smallframe over the course of 3 or 4 issues. I can't remember what race cylinder that they used. I also seem to recall that the cases that they used needed to be machined for some reason. I'm going to have to search though my stack of magazines and try to find those issues.

Hi,

A rather good setup, from my experience, is;
-iron cast polini 130
-decent 51mm crank
-Polini reed intake (on casings)
-Polini Snail Pipe exhaust
-19mm, preferably 24mm carb
-Electronic Igjnition

I've had that in my 90Racer, and I could cruise at 55-60mph.

Not too expensive, but very reliable if done correct.
-do Your homework With both ignition and jetting, and you'll have fun for years!

S

See the polini cast iron also has one with new head.
Cant decide on
Polini 130 cast iron
Polini 133 alloy
Or parmakit ecv tourer.
With lth road and simpel race crank.
24 mm carb
Have seen what the good old 130 polini can do.
But I always like to different, not do what everyone goes for🤡

I wish they would publish port timing figures. Would make it easier to choose.

on GSF: (google translalte)
57200.00 parmakit-
Exhaustion time 178
Overflow time 122

Some italian web page
Polini 133 alloy
exhaust: 178.
overflow time: 126

polini cast iron with new air flow head
did not find any info:-(

Ican not prove that these are correct, but the polini alloy is from pdf file with cylinder kit

Cheers T5Wilhelm!