Modern Vespa

Hello guys,

Need some basic advice for setting up mixture for 2 stroke.
Made some modifications to intake ( more air ) exhaust and upjeted.
Bike rides find but need to sort of starting and idle and need to know what carb say to me when bike does not want to start in the morning and if eventually does so it dies if I touch throttle with chocke.
Other case is after long run when stopped for a few minutes doesn't want to start if I don't help with throttle.
Need some basics about what does these symptoms says.
Will put a side any mechanical issues and want to focus on setting up the carb.Bike has been running fine before tune.

My first suggestion would be to put it back the way it was. Unless you have a fair amount of experience tuning, randomly changing things is going to lead to nothing but trouble.

Having said that, if it is hard to start and won't acelerate when cold, almost certainly lean at idle. So need a bigger idle jet. If you are looking for performance, the idle jet should be rich to the point of almost losing revs, so transition to acceleration has enough fuel.

Not wanting to start when hot means that more fuel is being added than needed. This may just be the carb is overheating when sitting still and the float bowl is boiling. It might be a leaking float valve, flooding the engine. If your carb has some sort of auto-choke, possible it is engaging even when the engine is warm, which it probably shouldn't do.

In general 2-strokes are happiest, provide the most power, and run coolest when they are jetted on the rich side. Horrible for emissions and fuel economy, of course. When messing with jetting, better to err on the side of being rich. If you do not already have one, a fine-wire-electode spark plug will usually work better with uncertain mixture control.

Again, unless you have experience, or are willing to spend time and money learning, refer to paragraph one.

I think the best place to start is a good water based lube

Jimding I appreciate your advice but it can not be a rocket science since kids does it as well:)
A have a basic understanding how the engine works but I'm more in to cars rather thanks to stroke engines with carburators.
I'm running more or less correct main jet so the engine is running more or less safe in normal operations from 1/4 throttle to WOT an just struggling to determine if I have to upjet pilot jet as well.I allerady done that one size up since open intake brings more air but Im struggling to determine if it is on the lean side or if it is to big.
All in all you have to do things to learn and get experience

And as I said forget any issues.Bike was running fine so it is just due to new setup.Ive took care of initial settings so I can always go back to stock but I won't course it goes so much better:)

If opening the throttle slightly kills the engine, almost certainly it is running too lean at idle. Might make sure the choke is operating properly as well, along with verifying that the float level is correct. Also make sure that you do not have any air leaks on the new intake system. A slight air leak will cause the idle to be quite lean, but not make much difference when the throttle is open.

I presume you have an idle air screw, and that you have adjusted it for best idle?

Really very little difference between tuning a 2-stroke and a 4-stroke, except you want to stay rich on a 2-stroke.

Good luck. A methodical approach, with good record keeping, so you can trace your adjustments, should allow success.

Appreciate your advice again.I try to do things properly so there is no tape and things like that.
What I've done is actually modify stock airbox to bypass restrictions and drilled some holes so airbox is stock from foam filter in.
And boy it did woke up the engine. As I said from 1/4 to WOT is running great and plug looks spot on to me as you can see on the photo.
I struggled just to get idle and mixture.Find it much easier to look for lean or reach condition from 1/4 outward.