Modern Vespa

Is this a standard PX125 carb? I ask as Ive seen it listed as a standard carb for a PX125 and a PX200 which doesnt make sense..or does it?

It is standard for 200cc engine.
Also works perfect with 177 kitted engines and above.

I think it can be jetted to suit standard 125 or 150. Especially if you have non-standard exhaust.

Thats interesting. Thanks for the swift reply!

Stay safe in Ukraine!

Thanks for support!

On this forum are more knowledgeable guys, I think bit later they see your question and will give response.

Are all the scooters you have on your profile ones you have now or just ones you've owned? I had a 1978 50 special in 1982 when I was 16. Loved it wish I'd kept it!

I thought all original carbs were Dellorto. This is a Spaco. Also, I believe the P125x came with a 20/20 carb. This would be an upgrade.

EDIT - you're on the other side of the Atlantic so I do not know

Hmmm, beedspeed list it as a Dellorto SPACO for a 200

https://beedspeed.com/products/vespa-px200-si24-24e-carburettor-dellorto-spaco-bgm-pro-faster-flow-autolube

Well Im satisfied it isnt standard on a 125. The scooter apparently has a Malossi 187 kit on it but the seller was a trader and had no other info. Thats why I wasnt sure what carb it was. I have no idea if crankcase has been ported or gearset changed. I just know it has a sterling SS expansion pipe RHS exit and a lot more compression than either of my previous PX's, 150 and 200. The autolube is disconnected and so is the electric start which Im told is due to the cylinder fins getting in the way of flywheel starter gear. Taking the carb lid off is the only investigation I have done so far.

Important thing is how does it run, and how does it GO? What jets does it have and how does your plug look?

It runs fine and starts easy but only just got it and plug looks fine. I never took jets out. Not taken it out yet tho as stored in friends garage in another town as dont have a garage at mine and simply not had the time yet. Its not been my main transport but will be at the end of the month, when I will be using it more regularly.

Its been 20yrs since my last vespa but in honesty 40yrs since I really tinkered with so a little nervous about messing things up as Im miles from any scootering friends (a couple of them run the youtube channel shedtune) that can help and dont have the biggest budget for repairs.

So yea just being cautious probably overly…I already lost the ignition barrel retaining grub screw down the frame and failed to change the barrel as the method I saw on yt and asked about here failed. The only hole I could find to "poke with sharp object to release the barrel was where grub screw came out of and that was a fail (seat has missing lock so wanted replace all 3 barrels for matching set). Just gonna buy a new seat lock for £50 (gulp) its a yankee so needs the long one and keep two keys on fob. Also had replace rear panel indicator wire as connector was missing. Thats done now. So yea will update on how it runs in a cpl of weeks once I get insurance set up.

Is that it, in your avatar pic? Nice looking bike!

Malossi 187 kit, Sterling expansion pipe and a 24 carb... and gonna be your main transport at the end of the month. Your ONLY transport? Hmmm, I'd suggest getting your jetting info posted up here so you can find out if it's likely in the ballbark and maybe consider getting a CHT gauge? Last thing you want to do is seize it right off the bat.

Yea thats it in pic, thanks, its a 2006. What's a CHT gauge?

Oh I say only transport but Im not working so dont have any regular commutes. So can be a fairly fair weather rider with it.

Ok so yea google is my friend..a temp gauge. I've never been a big thrasher of my scoots.

Are seizures common with those kits then?

Yes mate, all that scooters I have now.
LML is my first geared scooter, bought it in 2016 and still have it.
Then was 50 Special - my first classic Vespa.
Then P150X.
Then Nuova.
And the last one is PK 50 S.

Nice collection!

No if you have proper jetting, ignition timing and healthy engine

Ok cool, will take jets out in a day or so and photograph. What would be ideal jetting?

Every engine is unique. So there is no straight answer.
To start with take your spark plug out and make some photos of how it looks.
For example IMHO right looking plug colour.

Yea I took plug out and it had the correct kinda biscuit colour but i didnt photograph it. It has what feels like twice the compression than even my brand new px200 had back in 2003…Or maybe Im just weaker! 😀

What does it say on that tag that's bleached out in your pic?

Dont know why people get hung up on spaco v dellorto, spaco made them for dellorto and hence you find them with dellorto spaco stamps on. There can be some variance in the pilot mix screw threads meaning you could be winding out three turns rather than 2, say, but this isnt an issue. I see no point at all of running a 24mm carb on a standard 125; quite frankly you can run a 20mm carb on mild 180 kit, such as a DR adequately. The beauty of a 20mm carb is there are defined factory jet settings for them against the particular px125 you are running. Euro PXs are often set leaner at factory, they differ to US PXs in the jetting tables, especially in the later runs to comply with emission laws. All these standard jetting combinations are available online.

An Si 24-24 is not standard for a PX125. As I stated in one of your other threads, I believe you have a Malossi 166 cylinder kit. It would not be surprising to see such a kit paired with an SI 24-24, although, as ferriswolf said, it is not really necessary. There is no point comparing OG Dellortos with Spacos because they have all been Spacos for years.

I run flat out at 65mph on gps on a DR177 , I have a 24mm and I hit top speed at 3/4 throttle which proves a 20mm in my case would do . I had a 20mm and only changed to 24 on kit fitting as suggested it would be better , it makes no difference at all.

Realise you're really happy with it and it doesn't seize. However, when the 3/4 to wot doesn't do anything much, on an SI carb, it means the air corrector is too big (lean). Guess you're running a 160. Might be more speed in it yet.

My top speed is revving out, so youre right, a clutch cog upgear would make it go quicker but quite frankly, 65mph it sort of freaks me as it just feels too quick on a PX especially when you get hit by a side wind. But in terms of the 20 and 24, when i was running a 20, I could reach same top end and performance wise no measurable difference IMO. If its a case of economy and you have a 20mm to hand and running on a budget, youre just throwing £90 at another part (24mm) which you dont really need. I guess if you were using a better performance cylinder like a VMC and you want 70mph, the 24 would aid that. Ive been running the DR for a good three years now and its been very reliable, it runs a bit rich on low throttle but everything else spot on.

This does confirm it. Your air corrector is to lean. Fixing this will actually improve mpg, while making it nicer to ride in the cruise.

You are right. The size of the carb doesn't affect the top speed very much. A smaller carb or bigger carb, both jetted correctly, will do the same top speed. Like with flywheel weight, it's all about the acceleration. If jetted correctly, the 24/24 will accelerate faster.

its ac140 be5 125. Tried many combinations to get right with this forum and ended up with that stack. Open to offers on other configurations

If still on the 24/24, I would try AC120/BE3/122. This will definitely be smoother.

Id like to be on the side of not seizing. I can try this setup as have multitude of jetting to hand. Is the config you recommended going to be fairly safe ? Appreciate about plug chopping etc, which I can do. Always hairy cutting your ignition at 60mph How does this configuration impact the pilot jet? I have multitude of pilot jets too.

This jetting is richer than what you have. Totally safe
Most guys run around for many years with pilot jets that are way too small. Just makes them run hotter and wear out sooner.
Once this new jetting is in re-do the pilot from scratch. Start 6 turns out on the mixture, one turn out on the tickover screw. If the jet's a contender, the rpm will be sitting at 1200 to 1500. Adjust until the revs pick up, 2.5 turns is good.
Not essential but best results are always with the AC and pilot having the same size air hole. Something like 55/120 is a good jet to start with.

I have the MY PX125 and the bloody mix screw is behind a starter motor. So this is a tricky one. Ive found myself taking off the carb and having to turn the mix then reseat. Its such a stupid design by piaggio.

My 200 is the same. Next time the carb is out, cut 8mm off the mixture screw and saw in a screwdriver slot. Then it's fairly easily adjustable with a small screwdriver and the slot makes it easier to count the turns.

Thanks Jack, sounds like a plan.