Modern Vespa

So close. Thanks for all the help here over the rebuilding of this box of parts.

TUCK.

Also, longer runway, easy 2.5mph.

That's not the top speed attempt, just after. I've got miles of flat straight lightly used roads at my disposal.

Awesome. You'll get there.

Nice looking scoot. 👍

It looked impressive though.

little more air pressure for less rolling resistance? Warmer day, colder day? Plug gap change?

You are soooooooo close.

Tuck.
Lean out the main 2 points for one ping (one run). *Sean Connery Voice* "One ping only".
Tail Wind.

Bobs your uncle.

60 degrees
Wind less than 3 mph
197' elevation

Pinasco 177 iron
Vape static a/c
18 degrees
Mazz cut crank
Fast flow tap
Road v1 exhaust
Case matched to modified 24/24 carb
AC 160
BE3
116 main
55-160 idle

25psi front
32psi rear

Are you running a CHT gauge? Reason I ask is I couldn't keep the temp below 300f at WOT with that setup. And I'm running the Pinasco 2-port 177 and vape AC, at 20 degrees, 57mm Mazz crank and Ffftap, road 1 also!

I ended up with 120AC/BE4/128 and 55/160. Flat carb slide. Temps stay under 300f at WOT, and 65 mph tucked on flat road, downhill a little faster.

60/8s is close for you. Just don't seize like I did because I wasn't running a temp gauge...

No temp gauge. Really don't want one. Have more brass coming this week to get it dialed in.

You could bump the clutch from 21 to 22 teeth. That'd give you the extra 2 1/2 mph with no other tuning changes.

Otherwise, you're going to need to eke more to end RPM's out of your motor, which may require more changes than just jetting. Probably intake and port timing changes.

Or you could wait for a good tail wind for your next attempt.

Possibly wait for a cold morning where it's closer to the mid-30 degrees outside? It might give you 1 extra mph. Wearing a spandex body suit could give you another 1mph. Now we just need to figure out where to get that last .5mph! Perhaps skip Thanksgiving dinner this week?...no, that's not realistic. We gotta think of a different plan.

Draft behind someone in a van?

I once (ONCE that is) drafted a B-Double Truck down the highway for many many kms, on a PX200, it was going 110km/h+ (70mph)... found that you need to keep within about 5m of it, else you get buffeted and near-on blown off scooter... it sure was fuel economical, & I would pop out every now & then, so driver could see me in his mirrors.
Just hoped he didn't drive over a Roadkill Kangaroo! Scary as all whqt not! Would NEVER recommend it, nor do it EVER again!

Ohh, amd I had the keys for the backup van in my pocket!, so they were all stuck waiting for me to somehow get back to them, oops.

Doesn't look half bad at speed. Nice job!

Thanks all.
Qascooter I'll replicate your jet stack and give it a go.
Stay tuned

Which tracking app are you using?

This one
https://apps.apple.com/us/app/speedometer-simple/id939507215

I did that once many years ago. Yes, it was scary! I was riding back home on Sunday after dark from a rally in Seattle, back home to Oregon. I tucked in right behind a semi hauling liquid nitrogen. Cruising Southbound on i-5 I stayed about 10' off his tail...keeping it at about 62mph for the next 90+ miles. I was sitting bolt upright with a vacuum draft that was sucking me closer. I also got 90 mpg the whole time! My guardian angel must have been working overtime to keep me alive that night. I'd prefer not to attempt that stunt again.

You could always Rollie Free it...

Or Craig Vetter it by adding a tail cone of sorts to the seat behind the rider.

My 150S ('09, LXS) gains 3-5MPH (60MPH -> 65MPH) out of having a flyscreen, tailbag, and a bag on the seat behind the rider to close up the gap between my backside and the tailbag. The idea is to divert airflow around the rider's arms (flyscreen) and extend/disperse the pocket of low-pressure air behind the rider, to reduce drag.

My earlier version had the tailbag on the seat (on a small wedge-shaped platform, since the S seat slopes aft behind the rider's position), and was similarly effective.

Honestly that run was so close with zero tuck that just tucking in would likely get you there.

Full tuck is my nitrous.