Modern Vespa

Hi, first time, long time. Pretty much a noob, but I am figuring things out slowly but surely.

I had to put a new carb in my fairly new to me P200 (long story) and after probably way too long messing with my mix and idle screws I finally got it running reasonably well. After a few rides, I now have very limited power, and low revs - and it seems to run better w/o the air filter in (which I haven't been doing extensively, just short loops around my cul-de-sac). Any thoughts on what could have happened, and/or what I should be looking at? It has a fresh plug, and I pulled and cleaned the carb and jets but the issue is persisting. TIA.

need info: what kind of carb - Del'orto or Spaco, size - 20/20, 24/24, jet stack, idle jet, air filter drilled or stock? Stock engine?

Of course! This is where my troubles began: had a 24/24 Dellorto in it. I pulled that to clean it a few months ago for the first time, and overtightened and snapped a float chamber screw on reassembly and failed abysmally in my attempts to extract it. So I ordered what was available from Scooter Mercato, which was a Spaco 24/24. The Spaco came with the shiny jets below: 118/be3/160 Main and 55-160 idle.

After some issues and advice I swapped the original jets back in (also below): 109/be4/120 Main and 50-120 Idle, which seemed to help, and is what I have in there now. I also swapped out the stock Spaco long hex mix screw with the shorter slotted version. Filter and engine are completely stock as far as I know.

TLDR:
Carb: Spaco 24/24
Jetting: 109/be4/120 Main, 50-120 Idle
Filter: Stock
Engine: Stock

Thanks!

Try putting back the mix screw that came with the Spaco. I don't think the Delorto and Spaco mix screws are interchangeable.

You're correct, they're not, different threads. This is a specific Spaco replacement though: https://www.scootermercato.com/Scooter-Parts/Carb-Parts/BGM7305

Pull the carb.
Carb threads will be stripped. It's super soft.

See if you can still get the Spaco screw's cone to fully seat/protrude by finger into the channel opening underneath the slide.

I think that the jets - 55/160, 118/Be3/160 is a good set up on a stock auto lube engine. Be aware that the normal 1 1/2 turns out on the mixture screw on the Del'orto is about 2 1/2 turns on the Spaco because of the finer threads. and the 109 main is way too low for a P200 engine.

Have you set the timing? Also, just curious, where in FL are you located?

I have not set the timing and have no idea how to - I'd have to dig in on how to do so.

I am in Bradenton; south Tampa Bay Area.

So go back to the jets that shipped w the Spaco - I'll give it a shot. I should have mentioned autolube has been long disconnected, so I am premixing. Would that make a difference?

I'll take a look!

A good guide to checking/setting the timing:
https://www.scooterhelp.com/tips/timing/electric.timing.html. On the P200 it's pretty easy to confirm you're timing is in the ballpark - check that the line on the stator and flywheel line up in the window.

Great, thank you! I'll see what I can figure out and report back.

the 118 jet is right for non auto lube

Did you disconnect the auto lube, or did it come that way when you bought it?

Came that way when I bought it. It was restored/tuned by a knowledgeable Vespa mechanic on behalf of the previous owner, not sure if he disconnected it, or it pre-dates him getting involved.

Ok, great.

While I don't discount the fact that the carb may be buggered. Set the timing first. My old honda guru always used to say: "90% of all carburetor problems are electrical in nature".

I was assuming you tried to thread your original Dellorto screw into a Spaco.
If not, ignore the above.

All good. I will check anyway as I'm not ruling out anything yet!

Any excuse for more tools and/or knowledge is ok with me.

Did you look at the UNDERSIDE of carbs & compare?
There are channels under an autolube, and if you got a different carb or didn't block them off then you are ib for problems.

What did you do to disconnect the autolube?

You beat me to it!

if you need help, I am off on Sunday, we will be doing some scooter wrenching at my house in lithia fl.

Oh wow, that's tempting, and would be amazing! I'll attempt a DM.

you can text me at 813 305 9499 I work on Saturday, but off on Sunday, we will start around 11 am