Modern Vespa

Hi after discovering that my 2003 125cc gt engine is basically shite ..I'm after peoples experience of fitting the malossi kits to 125cc engine..
I have phoned around this morning to get prices for a rebore of original cylinder and by the time I've added new piston ..only slightly more expensive to go the malossi route ..
I know I will have to upgrade other parts of the engine if going malossi..that's for later..

Malossi quote 75% more power and 85% more torque, which will completely transform your Vespa.

You'd be wise to shorten the service intervals, and components will likely wear quicker.

Is this a daily rider and your only vehicle? Or a fun vehicle?

In the U.K., you should technically update the V5, so you might pay more tax.

I have the engine stripped and will be upgrading parts once I have resolved the cylinder issues..
Do you have the kit fitted..!!

I don't have the kit myself, but know other people running Malossi kits on the air cooled 125cc (Sprint / Primavera).

Malossi have a great reputation.

I had the 172 kit on my old vespa t5 so know about malossi kits..just after experience from someone riding one..

not a direct comparison, but I was very pleased with the Malossi 190 kit I had on my Leader 150 engine. Power and torque increased dramatically, although I also up-jetted the carb, changed over the transmission to Malossi bits and added a stainless exhaust all at the same time.

Proved to be very reliable as well. just make sure you get all new gaskets installed correctly.

You'll be happy with this type of upgrade.

Brilliant thanks crazycarl..looking like I'm going to have to purchase the kit as original parts are getting so hard to get

If you are looking to upgrade your daily driver, I would stick with the stock 200cc Piaggio cylinder kit. They are about $200, or maybe cheaper there, and have a whole lot more metal surface for the head gasket. The compression is slightly lower too.
One thing to think about if you go to a 200-218 is the belt. The bigger engine uses the belt with double serrations and there is an idler pulley in the middle of the crankcase. There should be a threaded hole where you can mount that. The variator and clutch pulleys are also heavier duty. If you do try to keep it stock, except for the displacement, I would suggest a Kevlar belt. The Piaggio 125-150cc belt uses polyester belts, and might not hold up as well as you would like.

Motovista I have looked everywhere for a 200cc barrel with no luck and with the wrong cylinder head the malossi kit is looking like the only option..
I phoned around today to try and get the wrong cylinder head reconditioned but no one was interested or able to do the work..the one place that did do work on modern scooters... I had to supply any parts like new valves n stuff so didn't work out any cheaper than the malossi head..
the bike won't be a daily driver I'm too old..
I've spent over £600 on new parts now but wasn't expecting the engine to be buggered .. so with cost of scooter I have to finish..

Hi will the liberty 200cc barrel and piston fit the gt 125cc..this item is not cheap in UK at £267.. the piston in pictures doesn't look right..
So only slightly cheaper than the malossi 209cc kit..
Are there any other 200cc options I can look for..

I'm pretty sure the liberty was air cooled. And it will likely fit. But it's very low comression and the stock 150 air cooled motor works about the same.

If you were to purchase something like this:

https://scooterpartsco.com/gt-200-engine-c-3637_3641_3760/cylinder-kit-for-vespa-gt200-bv200-aprilia-843291-p-481.html

it's about £164. Shipping it via UPS to the McDonalds in Cambridge Circus on Charing Cross road, is about £45, according to Wise.com. The rest of the country should be close to that in shipping cost, but that's the address I use for my BBC Oneplay account, so it was easy to put in the shipping calculator.

Just out of curiosity, because it's likely not applicable in this case, what is the cutoff as far as declared value of the package, to avoid paying duties on imported parts from the US? And about what does a cylinder kit for the cheapest Chinese scooter cost, and what would be the name of that scooter?
Got any friends coming to Disney World anytime soon?

I've finally found a gt 200cc barrel and piston new old stock item. Its a lot cheaper than the malossi or new liberty barrel..
So gasket wise i will need
0.6 base gasket
0.3 head gasket to lower compression

Also will need
Smaller main jet for 200cc

I think that is it ..can someone confirm please 🙏

Sods law the barrel has been sold..but whilst looking on eBay it seems the malossi kit for the liberty is cheaper than the same vespa item..I started looking at other bits and it seems we are paying more for vespa than piaggio or gilera parts..

Hi there seems a shortage of malossi cylinder heads..so was thinking can I put the malossi camshaft in a standard head or do I need to enlarge the valves aswell

I've found a gilera runner vxr 200cc barrel no piston on eBay..
I assume I can use a gt 200cc piston in it ..

Will a gt 200cc piston fit gilera vxr 200cc barrel..I assume they are the same

Yes. It's the same motor. If you can grab the entire motor, there are parts on it that were stock on the GT200 that aren't on the GT125.

Thanks motovista its just a barrel on ebay no piston..

Hi Derek 88, thank you for this topic. Since my engine is toasted (I don`t know how much and what needs to be changed yet) I will need to rebuild it and I am also interested to boost it little bit, so I would like to follow your steps and learn from you.

Yep no probs zeb_cz..
Probable problems...head gasket...base gasket...piston rings...or if like mine nice chunk missing in cylinder bore