Modern Vespa

Hi guys. I am currently in the process of modifying my 2006 LX 150. It's part of a project that started 2 years ago, and maybe I will post it here once it's closer to final, at the moment it's a work in progress and I still don't have too many photos of the part two of the project.

For anyone wanting to check out how it's evolving, you can find it all here (vmtuning.blogspot.com), along with the mod of my other ride, the Honda Zoomer (basically a fuel injected Ruckus, too bad Honda stopped making them for the european market in 2012, you guys still have the Ruck). - Disclosure: long read

Anyway, the final part of it, which is still under planning, is gonna include a 187cc cilinder (probably from Malossi) and replacing the carb as it's having some small hesitations (reed valve from what I understood from my mechanic). I guess I should match the cilinder with upgraded jets (don't have much experience with that but a bigger cilinder would probably need more fuel).

Does anyone have any experience to tell me which carb is better for a 190?

Wouldn't want to go into racing carbs like Mikuni or Malossi as from what I understand I would lose the e-shock for one and would have to modify or let go of the helmet case under the seat, Naraku and Genuine Buddy are also a no go as the first is listed as a B-class replacement (very cheap though) and the second is not available in Europe. So I guess I should stick with the Keihins.

Her original carb is a Keihin 2600A, with a 82 main jet and a 35 idle jet which is still available from SIP. I see Scooterwest is selling a variant called 2601A for double throttle cable, although I never heard of a Vespa having double throttle cables and I'm not sure I can find it in Europe.

SIP also has one called Keihin 2700B with a 82 main jet and a 42 idle jet, which is supposedly for the LX125, although I am not sure why, as in the compatibility list there is also the LX150 listed, and a Keihin 2708 (no info on what jets are on that one) or if there is any other difference from 2700B and 2600A.

I am totally lost as to which of the carbs I should buy (if there's actually any difference between them) and which jet to keep or change with the larger cilinder. A bit of help would mean a lot.

Sorry guys. Just that I'm a bit dissapointed here.

It's been almost two days and only a handful of people (18 to be specific) bothered to read a message for help, not to mention no one bothered to reply with a solution. I know, maybe the few that read it weren't having one.

Call me old fashioned, but, when I put this sort of message on Turbobricks (true, it was around 10 years ago or more) asking for help for my old Volvo 240, there were more than 100 people who read it in the first 24hrs and I had around 5 different answers, offering solutions to my problem. And it's a forum comparable in size to this one, memberwise.

The way I see it, the purpose of an enthusiast forum is in most part about either you helping the rest based on your own experience, or asking for help from people who are more experienced than you (...and getting it), if those two aren't met then it defeats its purpose. If it's only about "my Vespa is so cute" then Instagram, Pinterest or Youtube serve nearly as well and you don't have to write.

And please don't tell me I should have posted on "General". I did it last time, on a different issue, with the same result.

Hi Katana. I've found that the traffic here in Projects is a lot slower. Only a couple people have commented on my current project but things over in General get a lot more views and comments.

I've got an '09 S150 that I've considered doing a big bore on so this is an interesting project for me.

I requested on the recent poll for subheadings that would make it easy to us to go right to certain subjects. It was denied. Surely someone has had this problem before but you're going to have to go to the search to find it. Wouldn't it be great if there was a Mods section with a Big Bore subheading and then a second subheading for leader 150's??!!

Well, thanks at least for answering. Yea, would be nice to have a mods section. Would be even nicer if it would be done by someone with more experience than us .

I mean, I probably won't start the big bore till very late this year, I got enough on my plate atm with the frame repair/replacement, paintjob and the full exterior modding and I am honestly barely waiting for the body shop guy to tell me he finished the body so I can put her back together and start riding. It was supposed to be ready one month ago already. Can't really blame him, he's a friend and doing it for free in between two paid repairs not to mention he's not a motorcycle guy, he's used to doing cars and my entire project was a bit too much for him.

So, tearing apart the engine to squeeze a big bore, replacing/modifying the carb and replacing the final trans, that's probably gonna have to wait till winter as well as replacing the brake caliper for a more effective one. But I got to admit, I will start to buy the parts early so I wouldn't mind knowing in advance what it would be best.

Hi katana,

Rob G is spot on, it's kind of slow in the Projects section. BTW nice work Rob G, your scoots looking good!

Sorry, I'm not much help but I did a Google search and typed in "Malossi 187 Kit Keihin Jetting Recommendations" and the following ScooterWest post from 2006 was one of the first things that popped up. I'd dig around there plus consider the altitude that you ride at for for some jetting starting points. Here's the copy paste and good luck:

Aug 3, 2006, 9:46 AMlinkflagquote
WE used to change jetting which is a very common practice when allowing the engine to breathe better, but after doing about 40 of these installs, we slowly realized they just ran better with stock jetting.

The malossi 187 kit improves power greatly, but not top speed so much. It will be much easier to hold 55-60mph, but due to gearing, won't get you much over 70mph top speed in optimum conditions. So yes, I think this setup will help your situation greatly.
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Thanks a lot for the help.
I was aware of the power vs top speed issue, that's why I said I am planning a dual move, big bore+final transmission, both primary and secondary, to improve that too. Will probably try the Keihin 2700B as carb.

L.E. Forgot to mention, love that Pacific blue color you got on your ride.

katana pop over to the Sponsor Classified section I just asked Motovista about this and his response is to use the original carb.

Got it, read it. Well 2600A or 2700B are almost the same carb, only a bit different on jets. Notice SIP page with info on carbs for the LX 150. All 3 carbs I talked about are there, only for 2708 there's no jets info. For the other two, primary jet 82 on both, secondary jet is 42 on 2700, 35 on 2600. I was thinking of upping them to 92/42 maybe like the jets on the GT200, no matter if I go for 2600 or 2700.