Modern Vespa

I have an lx50 and my wife has an s50. She has always left me in the dust. I kitted my lx with the malossi kit and power cam and love the results. Although I am faster than her right now, it makes riding much more enjoyable to be able to just keep up.

However, we really want to kit her s50 to see if it performs better like mine did. I have seen lots of posts regarding the lx50 kit, but none on the s50. I know the malossi kit is the same for both models, but my mechanic is sure that the power cam is different. Has anyone else done this? We don't really want to be the first

No one's posted about it, yet. But several people expressed an interest in doing up one.
Sorry.

I would definitely love to know how that works out for you, I am in the market for a scoot and was thinking about the lil S50 and was wondering how if would perform modded, I had also heard that the S50 was quicker off the line than the LX50 and am glad to hear that confirmed.

The cam is 100% different. The S50 is a 4-valve, and the LX50 is a 2-valve, hence the faster S in stock form.

When I had an S50 I was thinking about installing a kit before I upgraded. Allegedly the Malossi M317083 kit works, but I wasn't able to find anyone who could verify this is the right kit for the 4-valve S50.

http://www.sip-scootershop.com/EN/Products/M317083/Racing+cylinder+68cc+MALOSSI.aspx

i'd love to know you top speed on the MALOSSI LX 50.

Thanks,

Dave

On my LX50, top speed is right at 53. It feels like it will do more, but I don't want to push it.

For me, it's not the top speed that matters. It's the power off the line and the ability to accelerate up hills and through traffic. The difference in power is surprising. I highly recommend the upgrade. My mechanic has done several of these, so I trusted him to fine tune it just right.

I've driven 1000 miles since the kit was installed and performance has only improved. Especially since the 600 mile oil change.

We're still considering kitting the S50. The consensus with mechanics is to install just the Malossi kit. There is no need to change the cam, like drewteague mentioned. If we decide to do it, I'll be happy to post the results.

The correct big bore kit for your 4-valve S50 is 3113905. Listed as such on here: http://www.malossistore.be/famiglia2.aspx?type=M&M=250&MM=MO/VES504T#&&/wEXAgUDTW9kBQpNTy9WRVM1MDRUBQRGYW1HBQItMQakI6cCW1DhJeRE0u483DVX3SPu


Matt C.

I saw that one too, but it is just a replacement 49cc kit for the original cylinder. Same SKU as

http://www.scootershop.gr/product_info.php?products_id=3205&language=en&osCsid=5c2333715da7e25b6ec16a998be00259

After talking this over with our mechanic and hearing what was said on this post, we decided to buy the kit. Plus, on the website where we bought the kit, it listed the S50 under the "scooter fit" with this kit along with the LX50 and the Fly 50.

We took it to the shop and after a couple hours, the mechanic discovered that the cylinder kit fits, but the piston hits the valves. The original piston is scored in a cloverleaf design to accomodate the four valves, so the new piston needs the same pattern machined into it. Needless to say, he was quite upset and so am I.

Vespa or Malossi apparently hasn't created a cylinder kit for the S50, so this is the conclusion: The S50 can't be kitted as of this date.

I seem to remember reading in previous posts about the need to mill the cylinder to accommodate the valves. So the question I have for someone out there who knows is whether this is normal (i.e. you get a kit and have to machine it to make it work), or whether there is no plug-and-play option for the S50. Munsongeek - thank you for returning and describing your experience with the kit.

The picture below shows what the piston would need to resemble. This is the only picture I could find that is close - it is not a vespa part. It is just for reference. The original S50 piston has smooth divots in the crown unlike this picture.

We have the 78cc 4-valve kit in stock for the S50 if anyone wants to try one and report back to us. We've sent a few out already, but no one has volunteered a write-up.

This was the kit for the 2-valve LX50 and S50. There is a different kit for the 4-valve S50. We do have those if you'd like to swap it out. Our apologies if our website was misleading. Fitment issues between the two were only sorted out recently.

This is great news! Can't wait to get the proper kit. I'll be happy to post the results when we're finished.

Yesterday we got the new kit installed. The results are incredible. Side by side with my kitted LX, the S50 has twice the power off the line. Of course, that is to be expected since it has 4 valves. Also remember you don't need to purchase the power cam like you do the LX.

Before I continue, I would like to mention that Vespa of Orlando AND Motorsport Scooters have been outstanding. This has not been the "ordeal" it could have been by any means. This has been a good experience.

At the beginning of this thread I mentioned I didn't want to be the first one to kit an S50, but to my knowledge and the responses on this forum it's possible we are, at least in Central Florida anyway.

I was very impressed by Max's (Motorsport Scooters) public response on this thread that there may have been confusion about how the first kit I purchased was listed on his website. He offered to take back the part I purchased that didn't work in exchange for the correct part with no recourse. Also, Vespa of Orlando (Dave and Adam) after putting in a full afternoon with my wife's bike and not being able to complete the job because of the non-fitting part didn't charge me for the labor that day.

I mention this because I know neither of them had to go the extra mile for me. But this reassures in me that there are people out there that still know how to take care of their customers. Usually, there's a big fight first. I hate that. They didn't hesitate to take care of us. Thanks very much!

Now, we have to find out how to adjust or disable the rev limiter on the S50. That will be for another post

Below are some pics: (Thanks Dave for taking them!)

I'm so glad that the second kit installed smoothly, and that the results were so impressive!

Excellent!!!
Looking forward for the full review.

Note to self...must resist buying the kit.....argghhhh
At least I know where to to buy the kit in case of an impulsive urge:)

A warning that your top speed won't change, but getting there is twice as fun. We're working on a way to increase the top speed and will post the results when we get there.

I don't know much about scooter mechanics.... but do you need to change the jets ? not even sure if they are jets in carb engine

To help bump the top speed up, a decent torque driver pulley and a gear up kit will do wonders!

Shame they are nearly all straight cut gears so whine a little...

That is outstanding! What is the malossi part number for the kit?

Part number is M3113905
Here's the link (great price too): http://www.scooterwest.com/items/?_pageCCS=t#page=/item_details/Malossi-Cylinder-Kit-78-8cc-4-Stroke-(w--Four-Valves)/3609

(copy and paste the whole link)

WOOOHOOO!

Just ordered the S50 Kit, the 2009 vespa calendar and Super White Headlamp from scooterwest .

Now got to take some performance reading before I get the kit installed.

Wow I was able to resist my impulsive buying by almost 24hours... A first for me :0

Hello everyone, two weeks ago I bought the new Malossi 3113905 for a 4v-4t for my Vespa S50 @ scooterwest. (Thank Max by the way). I'm, for sure, the first in Canada to upgrade my S50.

he's currently on the operating table ... My dealer asked me if we should replace the roller clutch or the original ones can remain in place. I also read somewhere that should swell the carburetor jets have a size you suggest? It should also define the tachometer to the CDI to obtain a significant gain in speed is what someone has to make this change?

I expect you and I will keep you informed of the process.

as noted by drew's tagline...

Rollers should be lightened....I went from 6 gram stock to 4.5 in my 2 stroke Typhoon, and increased my jet from a 60 to a 72, and up the needle one notch.... clutch springs and varo spring should be stiffer, so you stay in your power band.....
The best way of doing tuning, is to buy a set of jets, and start large, and work your way down....and do plug chops and test runs....Would like to hear how your top speed increased.....

Just got the kit.

Mechanic is schedule to put it in tomorrow.

But if I look at the head, I only see 2 grooves... shouldn't it have 4 because of the 4 valves ?

The booklet also shows the wrong part number.

I think I got it, the 2 valve kit has no grooves for but the 4 valves kit has 2 grooves for the valves.

Yep. The 4-valve setup has two of the valves horizontal with the piston and two at an angle. There isn't much room on that head to cram everything in.

I am glad these are available now - I looked for these when I had my S50 and they weren't ready yet.

You got the right kit ! Only the booklet is not ok but the instruction to install are the same. You also get it @

http://www.malossistore.be/Prodotto.aspx?type=M&MM=MO/VES504T&C=3113905

Don't worry and read that mail you'll be happy and there a lots of infos that you need to upgrade completly your Vespa. Waiting for news about you.

best Regards.

here's the post that i just send to Max at scooter west. :

Hi Max,

2 weeks ago I bought from you guys the 80cc Malossi 3119035 for my vespa S50 4T-4V 2010.

I just want to let you my feedback about how I'm happy.

Now I'm riding my bike @ 80 Km/h (48MpH) With tork !
It's fast, powerfull and still economic.

But you have to tell to your customers 2 things if the're buying the kit. :

1 - Jet the carburator to 76-78 (original is @ 72 kheinin)

2 - Remove the spacer on the cluth and make a little hole (diammer of 5 in the small place of the CDI to void the RPM limiter.

FYI : The CDI is in front of the bike located just beside the horn under the piaggio sign)

You'll notice a huge gain of speed and appreiciate acceleration.

So that's it, I'm really happy, event if the operation cost almost 750 $ including labor cost !

See you later and thanks again Max.

best regards,

Vinomini

OMG just got back from the shop.
Kit installed! What a difference.
No up jet/ no mods to cdi


Scoot can get up to about 75-80km/h, need to verify with GPS.

I now have power all the way up to 70 km/h.
Before I would have power until about 35-40 km/h and then it would just climb to 70 km/h.

Acceleration has improved by a factor of 2. I can easily out accelerate cars and pass them up at will up until 70km/h. (car that are driving at regular speed and accelerating normal )

Definitively worth upgrading unless you can get a 150cc without any major pain getting license,insurance....blah blah blah.

Two thing things :
1) the bike vibrates a lot more (more power)
2) when I turn on the gas at full I have slight hesitation that last a fraction of a second (carb?)

I'm extremely happy with this upgrade it's even more perfect for the city, the GTV300 project is now on the back burner

How is it that a kitted & camed LX50 4T 2V hits 53mph, and a kitted S50 4T 4V peaks out at the stock 39mph (before rev limiter bypass). Was the LX rev limiter disabled? I need to hit 50, but am looking at the 4V motor. Not sure about winding it too tight, though (killing the limiter). Thanks!
PS - This is a fantastic thread.

That's what we're trying to figure out. Our mechanic has ordered a new cdi because it might be defective. If it acts the same, then we'll know we have to do something to the rev limiter.

With my lx50, there was nothing done to the rev limiter. At 50/53 mph (a guess), the limiter kicks in and I can't go any faster. The s50's limiter kicks in at 42 and bucks HARD. The lx50 doesn't buck at all.

Thanks so much for the quick reply. I'll stay tuned...

I've been thinking about this. Given the same crank to rear wheel gear ratios, top speed is just a function of how fast you spin the crank. The 80cc kit is giving power, but shouldn't change the top speed if you're rev limited. I wonder if the S50 4V was rev limited out of the box, and the LX 2V was power limited (until you kitted it).
That doesn't really explain lilscoot's results (9mph increase), although that was approximate, and torque can definately feel like speed sometimes.

Nope I checked with the GPS and top speed was 73km/h so top speed did not significantly increase.

What threw me off is before I needed a long flat road to hit the rev limiter, now I hit the rev limiter even going a up small hill in no time.

I put 400-500km since I put in the kit. The engine is now running smooth but I have some hesitation problems which I attribute to not upjetting.

Kinda pissed since I told the mechanic to upjet but he refused saying it was useless. So got to fix it myself or bring it back to the shop.
Running lean is not good for the engine because it can overheat and diminish the life of the engine.

Nice. Thanks for the update, lilscoot. So for improved torque and top speed, it seems like the S50 needs the 80cc kit (Malossi 3113905) and the re-gear (Malossi 6712144) with a 78 carb jet. I'm going to keep looking around to see what I can learn about taller gears. The 6712144 is all I have been able to find so far, and they state "...our gears increase ratios slightly...". Somehow, it feels like all this torque could use more than a slight gear increase, espicially since I am after 50+mph. I'll post as soon as I get some results (won't be soon enough though, several weeks out, I'm sure).

Sorry, I'm new at posting so i hope this is right. I just got my S50 4v and all i had done was remove the restriction (the washer). I couldn't go past 59km/hr but now i go up to 80km/hr. I was reading all your posts and now i really want to put the kit to get an even greater accelleration but would i be able to go faster than 80 km/hr or do i need to do something about the rev limiter?

thanks

Just bumping the thread to see if anyone else kitted their S50s