Modern Vespa

hi everyone
Anyone got any suggestions? I have a 2023 GTS300 HPE, 18 months old and just had its 6000 mile service, since that's been done it NEVER starts first time from cold. It would very occasionally do this previously but now it's every time. I wait for the speedo needle to sweep across before hitting the start button as always, I've swapped the fuel in case of a dodgy batch but no difference. As soon as I hit the start button for the second time it starts, but what's changed?

First thoughts ...

1. do you hear the fuel pump prime when turning on the ign? (yes I know it starts on second press but asking anyway).

2. a video of starting with audio would be nice.

3. if you can hear the starter then it's not immobiliser.

4. if you can hear the starter then it's not brake switches.

Hi.. yes the fuel pump turns on and the engine cranks over, sometimes it fires but really slow like it's struggling, or not at all..

Battery? Have you checked the voltage *while cranking*?

just tried a theory.. ignition on, while the speedo needle swipes to the right I turned the kill switch off and on again the hit the starter and.. hey presto she fires up perfectly just like she should. I know it could just be a coincidence but maybe that's it.. I'll do this every time and see what happens. Fingers crossed!

showing 12.2 with ignition on, 11.8 while cranking, engine fires and it's soon up to 14.4
I'm wondering if water's been getting into the kill switch. Had a similar thing with my old Tommy 125 ( the Chinese one that looks like the old Honda Joker)
it cut out in a thunderstorm and found that water was getting in. Sealed round it with clear silicone and it was fine..

I've a theory and it involves the dreaded Evap system.
It's begun to get warmer over here in the UK, I only use the scooter for short trips and I've a habit of always keeping the tank full, when she wouldn't start first time it always felt like struggling for fuel. And the odd time cutting out after a hundred yards or so. Had a similar thing with my old Tommy 125 a few years back and found that keeping the tank no more than half full she was perfect. So last night I siphoned most of the fuel into 5 litre can I keep for emergencies so there was three bars on the gauge and BINGO.. perfect start.

Mine doesn't have evap so not really familiar with symptoms but ...

... think i read filling the tank to the top could upset the evap when too much goes from the tank overflow into the evap canister.

1st, disconnect the evap canister. there are good instructions here on MV on how to do this, just do a quick search.

If that doesn't solve the issue, it could be time to check your valve clearances. Even though the 6K service was just done, it's something most shops skip over. This can also be done fairly easy at home; a quick search here will yield good results. Basically, put bike on center stand, remove seat bucket, disconnect rear shocks, and use a jack to lift the body of the scoot and drop/pivot the engine, take off valve cover (8mm socket I think). Also, you'll need feeler gauges, but those are easy to buy online and not very expensive.

Good Luck!

Thanks!
The valves were definitely done, I go to the best mechanic anywhere, he's in our local club and he's got a GTS himself. More of a surgeon than a mechanic. Could diagnose a fault by listening to it over the phone..
Don't want to tempt fate but I've done three cold starts today with hours between, all perfect.. tank half full..