MOPED ARMY

I am building one this winter using the treats cnc Aluminum reed valve case half. I have some ideas and am just waiting on a couple more parts.

yeah, there was a dude from Wilmington (I think) that had one that he brought to many rallies 2010-2012-ish. Jake I think his name was? I'm sure someone will chime in. It ran pretty good and kept up with group rides fine but wasn't anything earth shattering. I saw that bike at WLR, dead peds, and maybe of our rallies?

If I recall his set up was different than what you're describing. I'm pretty sure it was one rotary case intake and one cylinder intake on what I assume was a bitubo top end both shas, one vespa sha and one "normal" sha

I also saw one at a swap meet in Milan a couple years ago. dude started it up but that was all I really saw of it. Dos guys and Willie treats were there, maybe they remember it better. (edited)

Sounds very similar to what I play on running!

Superbravo, Moparts aluminum racing subframe, stock cases, Kinetic CDI 9.49:1 CIF gear set, Polini variator, and also an MLM watercooled head. I've got a lot of wheels to pick from but I'm probably running some cool 10 star mags in the back and some 8 (I believe) star rare plastic polymer wheels in the front (we'll see if they fit). I like how skinny these wheels are. I have yet to find any radiator parts or a pump, etc.

I am going to instead be running the Malossi 43mm, probably stock rear pully and I have some springs I can play with. Mazzy anti special racing crank or potentially a drilled out stock crank with a 13mm hole in it (I haven't measured the crank yet to see if that will work, and I need to do some flow calculations and porting math but I think that's what I'm looking for.

The air inlet on the rotary side is opened up to 13mm like yours, and then like you said the pinasco half is 13mm, I may see about trying to open that up a little and potentially run a different intake that sits on a slightly different angle. I need to inspect the case half when I get it. If I don't modify it I'll run dual SHA carbs probably unless that's un-tuneable. I am unsure on pipe right now. Hopefully by the time this build comes to fruition Cranks can have his vespa pipe done, otherwise I will probably run a calibrata as well or I may modify a huge chamber onto a metrakit pipe I have.

Are you going to thermosiphon with your MLM head? I am opting to run a pump first so I don't have to worry as much about flow and cooling while tuning, but will probably try to upgrade to a siphon setup in the future.

Anyways, @andysimpon it's good to hear you've actually seen one in the wild a few times! I feel like dual carbs or not, vespas are often hard to build for serious speeds. That 50-60 range seems to be incredibly hard to achieve even with dual carbs or huge kits and aftermarket cases. Hopefully someone can chime in on the exact details of that build, would love to hear more.

This weekend some mope showed me some sweet aftermarket cases, throttle splitters, dual 13 SHAs, custom subframe, and fuel line T splitters, but I'm skeptical.

I bet those throttle cables are going to be a wicked mind puzzle when he gets to it.

Pretty clean shop you have^ . ;)

There is a way around that , but , it would likely require a lever with offset pivot on the larger carb .

I'd imagine tuning would be very interesting .

Some carbs have more over travel than others, you could always cut down the top of the slide a couple mm.

Lots of dirtbikes have splitter cables, usually when I need one I just buy a cheap one for like a polaris 2t quad or something that's gonna be hella long and cut it down. I think I used a 90s polaris 2t quad for my dt250 cable and it was easy peasy

Hahahaha hi Eddie. All this speculation and problem solving over throttle pull length . . . I'm running two identical 13mm SHA carbs (or at least that's the plan right now) so this will not be a problem for me. I did order one of the CNC halves that Tyler linked to in my WTB thread. If this build goes well I may do the dual carb dirty deed on my grande as well . . . but use a much bigger carb on the small half. The pinasco limits you to an 11mm hole in the small side of the crank. So IMO anything much higher than a 13mm carb is largely useless. Similar to the restriction on the stock spigot (but hey at least you have two of them on a dual carb setup). But, the CNC halve shoots right up in front the bearing/crank altogether so you can go pretty big on that carb. I was thinking of potentially pairing that with the new 46mm malossi and stock cases cut with their purpose built cutter. But that's all later on, maybe.

Brian said he is hooking the throttle for his separate carb up entirely separate, kinda suicide style I guess? Smash on the NOS at full throttle kinda style maybe?

Whoever mentioned malossi throttle splitter leaving you stranded . . . the one that came with the pinasco seems to be really good quality. I don't really see it being likely to fail. The little cam/slider fits nicely in the sleeve and it seems to be machined well for normal sized throttle cables. Yeah some soldering will be required but that's all fun. However I could see it being cool to just have a hard soldered Y shaped throttle. It may prove to make the sleeving and routing challenging but maybe even less of a chance of failure.

I've attached some pics of the splitter, I think it's really damn cool. And a pic of the engine mocked up kinda, just for fun. Was considering making a separate build thread but I think I'll just keep updating this one and encourage other dual carb vespa peeps to post their progress as well.

Just run one twist throttle, one trigger throttle like on Gopeds.

Or all you bukakke dudes are already used to the physical action of double twist throttles , so jack those pins bro

I was taking a look at how my XL600 uses the dual carbs on a single cylinder, only one carb has an idle circuit, and at idle the one without is closed off totally. Only once you open up the throttle like maybe 1/4 of the way does the auxiliary carb open up.

Obviously a 600cc single cylinder 4 stroke with 2 carbs is a lot different than this application though

Easiest thing you can do to figure out what?

I think dual intake into the same port is a different situation here performance wise because it's effectively very similar to just adding a bigger carb at that same location. Are you talking about the Y shaped intakes? With 1 set of reeds? I feel like dual carbs on separate intakes in different locations of the crank case, both using different types of induction, is quite different and probably much more challenging to tune.

That throttle cable looks like and uses a very similar mechanism to the one that came with my pinasco kit. The knarps are huge and would need some grinding/modification but I think I may just pick one of those up just in case. Thank you!

What I don’t understand is why you wouldn’t want control over each carb individually.

Snordly ran a double carb setup with individual throttle control on an e50 during pinball with a 16mm case reed and 24mm piston port. So fucking fast.

I guess I’m just lost on why people don’t mod Vespa cases for big reeds. I know there’s not much room but surely there’s enough to cram a 24mm ID aluminum tube into the cases and weld it in somewhere, then use a separate stand alone reed block

Modding stock cases for big reeds is hard, because the easiest access, RH small case half, still has to be able to fit in the sub, so just welding on stuff is hard, gotta be modular.

Other than that, the euro kids have been building rotary valve and AM6+ sized reed cases for these bikes for years, it's just a lot of work for a bike that has been pretty mal-aligned by the majority of the US moped community.

I couldn't count how many times I read negative comments on Vespa bikes when I was getting into things like 8 -9 years ago. Lo and behold, they are pretty much all I jam on now.

The last couple aftermarket/small batch subs all feature this, to make fucking with RH intake/reeds, and RH ignitions on the Sacre style cases easier.

The stock subframes already have so many issues with strength, it would definitely compromise it/require enough additional mods on a stock subframe to validate just fabbing a new solution.

Although I DO love the idea of just a drop section... been trying to think of a decent way to modify my aftermarket sub for easily installing my Sacre cases with the RH ignition.