Modern Vespa

Hello Fellow Forumers!
I am new here so first of all would like to greet everyone and introduce my self. I am a moto lover from Poland. Riding bikes for 20 years but new to Vespa. I've just bought a brand new 125 gts super sport. I'm not finished with breaki g in the engine but already started thinking about power upgrades.
The goal of this thread is to establish (please help and share your knowlage) what power upgrades are avalible for the newest 125 watercooled Vespa.
I will be searching all options to provide not only a power boost but a set up that will last for every day commute.
I know that it is prabobly better to just buy a 300 but let's please stick to the 125 topic. The reason I started this topic is me wanting to do longer highway routes apart from city driving. On the highways here you need a 120 crusing speed to be safe and not to ne pushed around by everybody passing by. So I would be satisfied with the stock hp if it was just downtown traffic.
So far I've searched this and other forums and know I can:
- install a Malossi cylinder kit (the biggest I found for my 2024 engine is 183cc - please let me know if I can do better )
- install a force master control unit (5519463 for the VESPA GTS Super 125 ie 4T LC euro 5 2021->). Will remap and move the rev limit 1000 revolutions up.
- install faster rollers (I want more top speed not faster acceleration from the traffic lights) - your input is needed here as I have no idea which ones will do.
My first questions are:
- can I do something to the lower end of this engine to make this or a bigger set up last (I was told that things can and will go wrong with this mod as it's too much for this engine).
- anything else you would recommend or change on my list
Thank you and looking forward to your input

Some variators increase acceleration, others increase top speed and sometimes one will increase both - so you need to research which variator (and roller weight) is best for your usage.

Malossi make a 183cc kit for the air cooled Sprint / Primavera. I'm not sure if there's an even larger kit available for the water cooled GTS?

Malossi do make a kit that changes the final drive gearing for higher top speeds on the air cooled models - they might offer the same for the GTS?

This video is obviously aimed at the air cooled models, but 120km/h (75mph) does seem achievable with 183cc's and some other mods.

I think I need to call a Malossi reseller here and ask what they have to offer.
A friend also tells me after the kit install you still should remap the scooter on a dyno.
I will update in a few days after I get more info. It is odd how little info is avalible online for the new 125 tunning compared to the classic.

Malossi do produce a force master, which is an ECU to match all of their modifications - rather than exploring a custom remap.

I know you didn't want to consider the GTS 300, but at some point it would be wise to consider the price of modifications vs the cost to swap either the whole Vespa - or even whether to explore if it's feasible / cheap to swap in a GTS 300 engine.

I did ask around how hard it would be to swap in a 300hp engine in but the answer was the 2023 up 125 models have some new bits that differ much from the 300 set up. It is the same chassis but too much to swap (cooling, electrics, etc.). This was the local Vespa service center guys. They also talked about the nigger cylinder set up being very capable but putting much strain on the low end of the engine - this is why I want to investigate if lower end parts are also avalible from Malossi or other suppliers.
Apart from that I do have a 1200cc harley if I want a bigger displacement. The fun here is to squeeze all we can from this engine although after all mods not much will remain

I know the force master has maps to suit the new components but I wonder how much they differ after being installed and broken down in a specific bike. Like with the power boxes you can buy online for a car vs a real tune on a dyno.
But this is just me wondering

With the modern vespas, I rarely see performance bottom end parts for the engine.

Most seem to only change the cylinder / piston.

I imagine the 183cc Malossi will have a more power per cc than both the 125cc and 278cc as it's a higher compression setup. It will also probably have a different characteristic.

One of the service guys I spoke to made many complements about the way the kit performs but also made it clear that these engines won't last long. Would be nice if you could change that with stronger rods, shaft, bearings, etc. I think it has mainly to do with turning up the revs - just imagine how much heavier there components get 1000 revs up.

I'm sure the correct nomenclature would be BIGGER cylinder when referring to cylinder size.

Wouldn't that be insane in a good way 🤣

Yes, the bigger cylinder the better but there might be a reason Malossi only makes 183cc (210cc for older Vespas). Maybe this is all the bottom of the engine can stand?
A 300cc swap in would do the trick but this would end this discussion as we are trying to max mod the iget 125 engine. Apart from that I was told by Vespa service guys that the new 125gts has less in common with the 300gts than previously and this basically means replacing to much parts for this to make sense. Having a large cc bike I am only interested in making a 125 champ.

If malossi or polini do a camshaft you might want to consider that as part of your plan

Exactly the point. I would replace all moving parts and main bearings. Question is are they avalible. I might have more answers on monday.

Did a quick search, looks like neither do a camshaft. So cylinder + exhaust+ forcemaster seems about it

The question is then is this a racing set up to last a few months or can you daily drive this the next few years (with regular oil change and easy driving but frequent 120km/h full speed runs on the highway).
I'm starting to think it is not a problem of tuning the engine to a higher hp but a problem of the lower end giving in if we stretch to far.

I ain't no expert on this topic but I'd expect the above mentioned combo would not cause longevity problems.

120 on the speedo(more like 110) or 120 on the GPS?

I have to wait for the malossi resellers to get back to me. I should have more info later during the week.
I heard different results from this set up. From 110 to 140 but you might be right. But keep in mind that I will use the extra power for max speed not torque.

For your particular GTS, the most bang for the buck is the Malossi big bore kit 3117737, Force Master 5519463 and Variator 5119760. After that, it's more money for smaller gains.

Thank you for the info Motovista.
Is this variator the top speed or the torque one? I don't need faster acceleration but do need to max out my top speed (hoping for 120km/h).
I was hoping there would be a bigger bore cylinder (the older Vespas had a 213cc) but it looks like 183 is the max for the new iget engines.

How about durability? I'm using Vespa GTS 125 iget 2017 model, which kit is most suitable for my scooter?

How is your GTS 125? Did you upgraded it?