Modern Vespa

Hey folks! New to the forum here. I bought a Px 150 that had multiple engine issues. Upon the rebuild I found some issues with the cylinder and crank. Ordered new replacements to find that the cases were shot when I pulled the main bearings. Pulled the trigger on a VR One 150 case as the crank and components I had already ordered.

Building with the following-
-VR One Cases
-BGM 177 Cylinder Kit
- Worb Pro series Flowed Crank, 157 Stoke, 105 Conrod.
-sip fast flow tap.
-zero porting for this initial build.
-sip Cosa II sport clutch
-dellarto phbh 30
-exhaust is TBD.

Does anyone have a rough estimate of what kind of power this thing will put out? I have seen lots of builds on rotary valves or LML reed cases, but not Many folks building on the vr platform.

Cheers!

You should get somewhere in the mid to high teens with the stock porting.
Maybe as much as 20, with enough base gasket.

The BGM kit comes with some options on base gasket.
I think they recommend a .8 squish.
You could figure out which base gasket gives you that - and see what you think.
I suspect you might find it runs out of revs a little lower than that motor would like - due to port timings - with that set up - but it will pull like a truck.

I'd guess below 20's with an expansion pipe.

Should pull good wheelies!

You'll get into the high teens with that build. You really need a 60mm bell crank to take full advantage of the other pieces of the kit. You're not going to get the torque you're probably looking for, and won't have nearly the latitude to play with port timings on the 57mm crank. Still, the BGM with the inset head is your best option with the stock crank.

If you go with a box exhaust, you'll trade a little bit of peak power for a wider power band, which is where I would start. Your neighbors will also thank you.

Aim for TD of 124 and don't worry about your exhaust timings at this point.

What ignition are you running? Fixed or variable? And what reeds?

And welcome to MV!

Thanks Chandlerman!

Currently the ignition is the stock fixed ducati CDI. I have to rewire the stator today, so if i botch that beyond repair I may go the Vape route unless someone has a better suggestion. Honestly, Im not sure whether I want to give SIP any more money after my last couple interactions with them.

Im with you on the 60 stroke. It really sucks because when I found out the cases were shot i went to cancel the order for the crank, cylinder and clutch so i could build a quattrini 244 on the vr one 200 platform. But, the company had already shipped the order so i got stuck with either eating the shipping and sending it all back, or sticking with the original plan and 150 cases

I have a sip road 2.0 on hand right now, not sure if I want to throw that back on for the time being and wait until i have it dialed to go for another exhaust.

Oh, the reeds are the x360 malossi reeds that came with the case.

The SIP Road 2 will do just fine. You can get a little broader peak from the Polini/RoadXL/Big Box, but not enough to spend cash on it if your ultimate goal is a tuned pipe.

I like the VForce4 reeds, but they're also not cheap and, again, the Malossi reeds are just fine for what you're building.

I share your SIP-order pain(won't bore you with the stories). So far SC hasn't failed me, shipping the same day even during the German parts-buying high season. Unfortunately, they only carry the BGM ignition upgrade, that stinks.

The Vape is wonderful. With that level of build you're doing, I'm guessing you'd be much happier with a more modern ignition system.

How are shipping costs?

Ray, it blows me away that such a large company can have such terrible logistics and customer service.

I have been frequenting SC, their shipping is reasonably priced and their turnaround time is top notch. Generally I haven't waited more than 3 days for parts. Blows me away!

One thing that I've noticed with fair frequency is that my Fedex SIP packages in particular spend a lot of time ping-ponging around inside Germany before suddenly popping up in Memphis.

Also, Scooter-Center has never come back and given me the super-irritating "send more shipping money!"

Go to the next step, past the page that gives you a total with shipping.

Default shipping quote is Deutsche Post. In the next step you can choose another carrier. UPS 2-4 day is generally 1/4th that.

sr2 and xl are outdated
new and very good is polinibox

keep timings low
18-20 u will get
use CR linings
ensure using an AS atomizer
and with reed and big carb mount a fuel pump

Hey Freakmoped! Thanks for the response! When you refer to CR linings what do you mean? Also, do you think the fuel pump will be needed on an un ported 177 kit? I was hoping the fast flow would be enough, but would love to hear more.

For the carb jetting I was planning on

55 pilot
Av266
X13 needle
Not sure on the main jet size yet, ordered a whole kit from kmt for 120-150. Does that seem reasonable? We are at 5k in elevation for a baseline.

Cheers!

Would avoid any other jets other than original Dellorto 😉

Jim, do you have specific reasoning behind that? I can understand that switching between jet manufacturers can be a mess, but tuning with a complete set of jets from one manufacturer? It seems from everything I've seen the KMT are to the same tolerances as the dellarto. I did just order dellarto jets from 125-140 earlier tonight as it seems like the KMTs may be lost forever in the Royal Post system.

Sounds a lots like our USPS
Order something small and time sensitive at your own risk.

KMT jets are excellent.

CR plates are aka CR80 clutch linings.

They just showed up today. Unfortunately, it seems like the new BGM 177 kits that are supposed to be compatible with the electric start are not. There's 2.4 MM of material in the way. Anyone else had this issue?

There are two versions: the first version does not work on electric start flywheels. if you try to take material away for the gear to fit, you will break through. The second version is reengineered to allow the electric start flywheels. i wonder if you received the first version. i've installed several of the 2nd version and never had an issue with the electric start flywheel rubbing.

maybe someone has decent photos of V1 and V2 side by side?? that would help to see what you received.

I'm in the same boat with you in thinking the wrong cylinder was sent. I ordered scooter center PN BGM1770NE, which is outlined as the one for the ele start. I just shot them an email, wait to see what they say.

Thanks for the help!