Modern Vespa

I'm running a Pinasco 177 2 port also on the BlueBomber.

But after FridayMatinee report on the VMC, and chandlerman report on the BGM, next kit will be something different than the Pinasco.

For sure
Will run my pinasco until it esssplodess.

Been a gem for me so far. Hope it continues to put miles and smiles on my gob.

I'd be pretty sure the 57 chrono with the 3 exhaust ports, does everything the stelvio does but goes faster, if opened up. And then way less economical.

I think it was Egig, referring to versions of his cylinders that has the option of one exhaust or three. He said the 3 port version is much more demanding in terms of precise jetting.

I found a FMP video with some numbers comparing Crono to Stelvio.

Referring to Crono: https://youtu.be/QmW9zP0T3iQ?si=TlhJXePibVfytjkd

?si=TlhJXePibVfytjkd

So if I'm reading this correctly, the Stelvio v2 would be the way to go for rotary intake?

Had a nagging feeling about timing so went back and checked it again with a strobe.

Nowhere near 20°.

Closer to 50°.

Insane.

Wow.

Surprised it made it that far!

I have the VMC Crono 187 with expansion exhaust and a reed setup on my track bike, and you have to mentally make sure to not completely loop the scooter out of every turn. 2nd and 3rd gear will lift the front wheel everytime. The power band is violent, it's off or extremely on. It's terrible to ride around the city, but it's insanely fun on the track. I would be willing to bet if you did a box exhaust and maybe up geared (I'm running stock small block gearing) it would be much more pleasant and still very fast for a normal riding scooter.

All that being said, I absolutely loved the malossi 177 for years and would recommend it 10/10 times for a non racing but fast/good upgrade.

Thx JohnDon.

Yellow'd no doubt be a blast on the track, but it's mostly a traveler.

Still trying to create a semi-reliable set up that can do distances on the 8's with some guts. It's been elusive.

Now this is going to be a funny story

Guess what running 50° advanced does to a piston.

Glad you tested timing again. I couldn't wrap my head around it being anything else just looking at your plug pic.

Regarding cylinder kits, the Stelvio V2 is getting good reviews. I have two BGM's and the older Stelvio. I don't think you can go too wrong with either.
The older BGM complaints were more rattle noise, but the piston has changed since then. It has a CHT port that is great. Responsive enough for jetting.
Stelvio V2 has a separate exhaust stub which is also great.

Polini box on either is delicious, but beware more than a few here have had trouble fitting it on 8's. I had to make a bracket for it to work but zero issues since then, even two up didn't notice that speed bump

A 24/24 carb vs 20/20 will be better* with either. Runs cooler and shifts the power curve to the right a bit.
BGM sells a (reworked Spaco) carb made with their kit in mind. Pinasco (also reworked Spaco) has a better reputation.
I've had enough anectdotal expereinces with Spaco's out of the box to say you'll be rolling some dice PNP without some ultrasonic cleaner and compressed air treatment, in addition to drilling.
*If you can live with a little four stroking at barely open throttle.
Good luck!

Thanks for that, Ray.

Still undecided about the new kit. No bad choices really.

For its sheer ability to guzzle tank-fulls of gas at WOT without complaining (until horribly out of time) I'm giving the Pinasco high marks. It was fun while it lasted.

All of that said, BGM products so far haven't let me down. I am running a BGM tap, BGM clutch, BGM jets, and probably some other BGM stuff on yellow I can't remember at the moment. Which is why I'm leaning in that direction.

Question for the BGM folks: What kind / size of sensor are you putting in the head?

I'm all wired up for a Trail Tech. They offer this - wondering if it can it be adapted.

https://cdn1.polaris.com/globalassets/trail-tech/2020/home/category-navigation/732-ez1.jpg?v=bde621db?height=680&format=webp

Damn Mike!
How does the bore look?

I think the Koso is also a thermoresistor, so it would work.

The sensor is this one.

Yep. I wish all heads came with this, makes it so easy. But that one won't fit the Trailtech plug. Some people have cut and re-joined the wires to the Trailtech but it never worked for me.

How about this Mike? You'd need an M10 bush with an M6 internal tapping. I can't recall how deep the hole in the head is but sure you could make it work.

https://www.trailtech.net/en-us/shop/accessories/support/vehicle-sensors/temperature-probe-sensors/sensor-temperature-probe-sensor-m6x1/

Thanks, Chandler. Was hoping to stay with TrailTech if possible but the Koso is Plan B. The probe looks huge, but might work! Thanks ginch The party's over for the cylinder. The rings didn't just melt. They fused into the Nikasil in places, like little spot welds. I'm calling it curtains.

I have this one and just ordered another since it's on sale.

The tach wire just wraps around the plug lead and the CHT takes any of the Koso options.

Just curious... because I don't recall seeing it posted in this thread... what temp readings where you getting when it was melting down?

Great question. Sadly, don't know because we had disconnected the temp sensor earlier that morning. We noticed some oil pooling under the spark plug and the consensus was the ring might not be sealing, so we took it off. Seemed like a reasonable idea at the time.

Not taking the time to check the timing was just total negligence on my part. I don't think any of the parts themselves failed per se.

It didn't seize, right?

Regarding threaded sensor options, I cut the Trailtech connector and direct-wired the Koso C'man suggested. It worked fine until I snagged the cable installing the cowl months later.
Not wanting to deal with the microsurgery again, and already confident with the setup, I fit an insurance policy ring sensor there using the Koso sensor to hold it. Doing well after a few years and a bit more responsive than an under plug, not to mention not having something that interferes with a crush washer.
Nothing compares to a threaded sensor in the head.

On my other BGM I've been running the Malossi for also a few years.
It has to be connected to 12v dc or it will eat the battery in weeks.
Oddly, I'll get an error code unless using a BR plug

https://www.scooter-center.com/en/temperature-gauge-malossi-dual-universal-25c-250c-13f-482f-69mm-32mm-16mm/p-30845.html

You do know that you just described a stock P200 engine swap. Just sayin.

Ha, maybe so! Guess I could steal the P200 engine out of the Boobadge and re-gear it for 8's.

What ratios did you finally decide on for your Briar Blue project?

I went with DRT 24/62 gears. It will be a while until i get to test ride with them though.

No, didn't seize. Lost compression when the rings turned to molten goo.

I like the way I have the TrailTech gauge mounted and it was a pain getting all the wiring through the headlight, frame, tank, cowl. May just splice in a Koso sensor. Thx.

Wild.
Fascinated by this, both the ride and the "event."
Plug is dark, so would a CHT have picked this up?
Wild. You have a trail wire to pull things. Should be easy
*Keeping in mind the Trailtech AFAIK-not-replaceable battery is 3-5 years.

So... made any decisions on new kit yet?

(please don't say stock 200!)

Good question. With the timing that far out of whack, ignition was occurring when the piston was still way down in the bore, so who knows what that was doing as far temperature in the head. And honestly, not sure what I would've even done about it. Had no way to time it after leaving Rob's garage. It was in limp mode most of the ride. The final meltdown wasn't unexpected.

Think I'm gonna stick with TrailTech. They have some options that should work. I've already got five or six of their gauges on my scoots and I like em. Some are more than 5 yrs old and not one has lost battery power. Well worth $50. Still pondering. Don't worry, not stealing the engine out of the P… yet.

Alrighty, then. Things move slowly in the scooter world.

Ordered a DC Vape a month ago. Dave says it's coming, be patient.

However, I am impatient by nature. And before destroying a new kit I want to find out if timing was really the problem.

Looking around the garage found an old but functional Polini barrel, a brand new GS piston, and a brand new set of GS rings. Why not?

Got some new points, a new condenser…

Let's do it.

Ain't no motor like a bitza motor, and I'm totally here for it.

Kick kick kick … come on … kick, kick, kick
[ten minutes later] kick, kick, kick, kick …

Time to pull the plug and spin it with a drill, figure out where timing is at that way.

I agree about the Pinasco carbs. I can only say good things about the quality...spaco less so..

Turn the ignition key on!?!

lol, in this case it's "ignition screwdriver" but yeah.

Got spark, fuel, plenty of compression … new condenser, new points, gapped, static timing's set to a reasonable spot. Ought to at least fire up.

Something ain't right. Flywheel?

chandler's right, need to spin it with a drill.

Have you done the old "spray some carb cleaner" trick to see if it will fire up?!

Not yet... might as well, need to get some … stand by

Also, my go to question in these situations: ' Plug wet or dry?'

Pull the plug, check it for spark against the case, then spin the flywheel it with a drill and see where the timing is at.

And don't forget that the flywheel nut will probably get knocked loose when you stop the drill, so re-torque it before you try to kick it again.