Grande carb upgrade

Kevin Bishop /

I have been tossing around the idea of finally putting a 13:13 carb on my Grande for 5or 6 years. I just never pulled the trigger because of so many other builds. It has the Malossi 64 and too bad pipe. I’ve done the intake patch job last time I was in there. I just never thought there would be any real gains?

I was always told the carb doesn’t really matter size wise. And bigger carbs just get you there faster. I don’t know how true this is really. Should I just save the money for new gears instead. It maxes out at ~43 idk really anymore

Re: Grande carb upgrade

Dirty30 Dillon /

If you're not into splitting the cases again and drilling the intake, you won't see any difference vs. a 12.12.

I don't typically even bother with going 13.13 on stock cases. If you want to increase your intake that much, invest in any of the myriad other case options, or even small half cases.

Re: Grande carb upgrade

I agree with it not really being worthwhile putting a 13.13 on in place of a 12.12.

If you are splitting the cases anyway and decide to drill the intake out while you are at its fine, but it's not going to be the upgrade that is a real game changer. It's no fun to wreck your cases in a failed attempt to drill the intake out either.

What variator are you using and what is your stock gearing?

Re: Grande carb upgrade

Carb size definitely does matter but a 12.12 vs a 13.13 is pretty minimal difference. Get taller gears and re-tune your variator. The multivar is great for the price if you don’t already have an aftermarket one.

Re: Grande carb upgrade

Dirty30 Dillon /

I'll second above, because getting new gears for the trans is not a 1:1 solution for more speed. You will need to tune the variator and clutch in order to best utilize the taller gears.

Re: Grande carb upgrade

Variator for sure, dollar for dollar the best money you can spend at this point.

Re: Grande carb upgrade

Kevin Bishop /

It was already drilled to 13 mm when I split the cases before. I just never bought the 13:13.

I’ll look into variator s thanks.

Not sure what’s in the gear box,it’s stock. It could use a going over too.

What happened to someone making aluminum rollers for stock variators?

I’m cheap

Re: Grande carb upgrade

> Kevin Bishop wrote:

> -------------------------------------------------------

> Not sure what’s in the gear box,it’s stock. It could use a going over

> too.

There are several stock configurations, and several choices for aftermarket ones. These wiki articles are helpful:

https://www.mopedarmy.com/wiki/Vespa_and_Kinetic_Transmissions

https://www.mopedarmy.com/wiki/Calculating_your_Vespa_rear_gearbox_ratio

> What happened to someone making aluminum rollers for stock variators?

No longer available, but you can get the same weight by choosing the 2.8g option here:

https://www.treatland.tv/vespa-piaggio-14mm-x-14mm-weights-pick-a-weight-p/vespa-14x14-weights.htm (edited)

Re: Grande carb upgrade

Me and Ryan dedpead were making rollers for stock but they suck tbh. They weigh a ton, they are a bad design, they have very little range and the amount of work it takes to make them perform less bad can be spent getting a good variator tuned perfecto.

There are a lot of good options for aftermarket variator, I made my own but I had some issues with production, might make them again someday, 40 of them are floating around out in the world, haha, the 2 I have on my own bikes still work great.

The dos looks good but I haven't run it, it's the same scooter based idea I had.

The polini is kinda the gold standard, it seems to go right on and work out of the box on just about everything.

The malossi, I tried one back when I really didn't know what I was doing. I think it's probably fine but on a lower performing setup the out of the box weighs were too light and I spent a lot of time messing with timing and jetting and generally being a doofus.

Then there are a few new options I don't even know about so hopefully others will chime in.

If you're in a budget, I would seriously consider the dos and order a big bag of cheap scooter weights. It's literally night and day having a good variator, plus the bigger range is like getting speed gears without losing low end.

Especially on the kits like malossi and Olympia that don't make as much top end. My cousin's bravo that I built him with a 43 Olympia/cut crank/ 12:12/ Tecno circuit was barely doing 40 with the stock vario and putting the MF vario on it got it to almost 45 (46 downhill!) And it trucks getting there. That kit doesn't really rev out so the bigger range makes a huge difference.

Re: Grande carb upgrade

Interesting that it's such a big difference, thanks for the info Graham!

I'm only using the stock variator on my vespas which are nice enough to warrant running side covers, because I know it'll fit.

Re: Grande carb upgrade

Dirty30 Dillon /

There's no fitment issues with aftermarket Vespa variators and covers.

I'm surprised to hear your thoughts on the deadped weights, Graham. I bought an original set years ago that I absolutely loved on a stock + setup. Made for a very fun 35 mph ripper.

I've tried a bunch of variators, malossi, dos, polini, and they're all worth the money.

Re: Grande carb upgrade

Sorry I didn't say that clear, the weights are fine, it's the stock vario itself that's heavy and sucks compared to aftermarket. I ran stock for awhile but the difference going to a aftermarket one is so huge.

> Dirty30 Dillon wrote:

> -------------------------------------------------------

> There's no fitment issues with aftermarket Vespa variators and covers.

>

> I'm surprised to hear your thoughts on the deadped weights, Graham. I

> bought an original set years ago that I absolutely loved on a stock +

> setup. Made for a very fun 35 mph ripper.

>

> I've tried a bunch of variators, malossi, dos, polini, and they're all

> worth the money.

Re: Grande carb upgrade

> Dirty30 Dillon wrote:

> -------------------------------------------------------

> There's no fitment issues with aftermarket Vespa variators and covers.

Huh, I could swear I read stuff about the polini variator not fitting under side covers. I had it in my head that it just didn't fit, so I haven't mocked it up.

Ah yes, in the reviews on treatland; apparently it doesn't fit with the dust cover installed. Though maybe that's not really necessary if it's under the side covers anyway.

I do wonder how the DOS variator performs...

Re: Grande carb upgrade

I think the consensus is that the dust cover just goes flying off the first time you rev it to 1000000 on the stand which you must do every time you build a new vesper.

JUST KIDDING DON'T REV IT ON THE STAND OMG YER SHIT WILL ESSPLODE

Re: Grande carb upgrade

Dirty30 Dillon /

> Graham Motzing wrote:

> -------------------------------------------------------

> I think the consensus is that the dust cover just goes flying off the

> first time you rev it to 1000000 on the stand which you must do every

> time you build a new vesper.

>

> JUST KIDDING DON'T REV IT ON THE STAND OMG YER SHIT WILL ESSPLODE

Yes, PLEASE no stand revvin. I had the Polini with dustcover on my big wheel ciao with fulls covers, not even close to hitting. I think if any of the variators will impact the cover, it's the DOS variator, as the ramp guides extend past the face. But I don't have any covers on my KS Si-Sub swapped bravo, so I have no idear.

Re: Grande carb upgrade

> Dirty30 Dillon wrote:

> -------------------------------------------------------

> > Graham Motzing wrote:

>

> > -------------------------------------------------------

>

> > I think the consensus is that the dust cover just goes flying off the

>

> > first time you rev it to 1000000 on the stand which you must do every

>

> > time you build a new vesper.

>

> >

>

> > JUST KIDDING DON'T REV IT ON THE STAND OMG YER SHIT WILL ESSPLODE

>

> Yes, PLEASE no stand revvin.

The videos of vespa clutch bells going nuclear are wild. I definitely don't want any more shrapnel in my life lol.

> I had the Polini with dustcover on my big

> wheel ciao with fulls covers, not even close to hitting. I think if any

> of the variators will impact the cover, it's the DOS variator, as the

> ramp guides extend past the face. But I don't have any covers on my KS

> Si-Sub swapped bravo, so I have no idear.

Good to know! I have a polini variator and I'll try it with my Grande and Bravo. I imagine the model and how warped the side covers are would have an effect... one of the ones for my nice bravo is practically banana shaped.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account