Modern Vespa

Thats looking so good!

Thanks for support. Sometime ago I installed new floor rails on PK S for my friend and it was very easy near 1-1.5 hour work... Thanks mate!
For the first time I will use old two tone trim that you can see on photos in this thread. It is very easy to install. Maybe later I will buy black rubber trim.

Okay.
Ignition timing checked


Air filter, carb case cover, cylinder cowling, flywheel cover and other small bits are on places.




And first kilometres was done!

Bravo!

Hec

Thanks Hec. For sure not finished yet but it can ride at least

No need to rub it in!

Hec

oh definitely yes

Now need help with jetting it.
Any advices and tips is very appreciated.
Please leave it in this thread - DR177 to VMC Super G jetting advices needed.

What can I do to prevent this smears?
Exhaust inlet sits really stiff on stub, to mount it I was need to use rubber mallet.

Double check the torque on the cylinder head. Mine had the same and once I re did that it stopped.

Head already checked.
I'm 100% sure that it coming from exhaust connection. Photos was taken after I wipe all clean first and then ride near only 60-80 km.

Just a pic

Exhaust paste…

Hardens to a ceramic form.

Doesn't stop it completely, especially after a ton of heat cycles, but definitely 90% of it, and better than not using it.

And needs care when removing the exhaust.

Looks like you're running too rich too.

I used copper silicone and all turns out much better. Bit not perfect but I can live with it.

Today I finally mounted side panels and glove box. Now I can say that my P150X is finished. But for how long?

NICE!

So good with no indicators. Love the look.

Luftgekühlt!
That's wild.

Gave it some quick polish before tomorrow classic cars and motos meeting.

I really liked the grey, but the black is really slick. Gorgeous ride!

I'm with you about color. But black was my only option. And when it comes together I start to like how it look

Winter is coming.
And I want to open engine to fix some mistakes.
I also want to match cases with cylinder and carb-carb box-case.

But general question is about primary gear.

Now it is 23/68 and it seems enough for me:
Top speed is near 115 km/h(72 mph) and when cruising on 90 km/h(56 mph) it is 6000 rpm on the tacho.
And gears don't feel "too short", rarely when changing 3rd to 4th it feels like 4th is bit long, but it depends from how high i rev 3rd.

I read here and there that people use 23/65 or even longer with similar engine setup.

Do I really need 23/65 with short 4th gear?
On the other side if it turns out too long I can go back to 22/65 and it will be same ratio as 23/68... but short 4th will be staying in engine...

What it have under the hood now:
VMC Super G, 177cc
Mazzucchelli racing crank 57mm, rotary intake
SI 24/24
Polini carb cover
Polini Box exhaust(I also have Sip Road 2 on the shelf)
Sip Touren flywheel 1.6 kg
23/68 primary gear.

Picture just for attention.

Nope. If you're happy with the current gearing, no need to change it up. If you wanted to be able to cruise at higher speed at 6,000 RPM's, you have the option. If you go with a short 4th, you'll get a little better overlap with 3rd, but also be cruising those same speeds at 6,500.

You need to decide which is more important to you: Better overlap with 3rd, which is good if you do a lot of accelerating up through the gears to 4th, or more comfortable cruising.

My Quattrini 181 runs with a 23/65 and 36 4th. It pulls really well and very rarely need to change down to 3rd. Cruises nice. I have a 24 and 22 cogs that could be used but happy to keep the 23 for now.

Playing with this gearing calculator it seems that if I will choose 23/65 and short 4th cruising speed rise up for near 3 km/h on same rpms. But overlap between 3rd and 4th will be better. And cruising a very little better too. Seems worth to try.

I forgot said about tires - now it is 110/80-10. But when it will be done I go to 100/90-10. But isn't Quattrini is noticeable more powerful than Super G?

When I still had my VMC 187 in me scooter I considered going with a 23t clutch cog (from a 22t) but never tried it. Having recently put a stock 200 engine in, I can say that the 23/65 is a huge change. The good: cruisey and quiet. You don't even realize you've hit 90 kph. It's not even breaking a sweat and feels like it will do that forever. The bad: Not much zip after that and it will be awhile before you're shifting into 4th. It suits me at this point. The 23/68 sounds like the best of both worlds. I wish I had tried it. The 22/68 was fun too. I know you can't really compare the stock 200 with a VMC kit.

The only issue with 23/68 is that there is little flexibility. There is no higher and 22 is much lower. With 65 all the cogs fit and one of them will work.

I played again with calculator.
And on today ride pay attention on tacho/speed.

It turns that 90km/h is on 5600 rpms. And 115 km/h on 9000 rpms.

But calculator shows 147 km/h on 9000 rpms
Where is my mistake or something not works proper?

I have gotten some strange results with gearing calculators. I take them with a grain of salt. The ultimate judge is your ass…in the seat.

I like the idea of being able to play with gearing by changing out a clutch cog. But trying out a different primary is not so hard either. Doesn't take too long to do if you are just pulling out one part.

You seem to use your scooter a lot like I do. Longer rides at a sustained 90 kph, but also lots of small winding roads at lower speeds. If you are able to handle both with your gearing, I'd say your doing pretty good

Happy trails!

Calculator showing a long 4th. That's not helping.
Calculators mostly calculate with theoretical measured tyre circumference. Not with someone actually sitting on it squishing the tyre.

My 221 will usually do 8900rpm in 4th gear. With 24/62 primary, 36 & 350x10, that's over 100mph. I can assure you it isn't that fast.

Overall it seems that current 23/68 is good enough. But maybe a very little not perfect Especially from 3rt to 4th sometimes.
Go to 23/65 will cost for me near $110 for new DRT 65T cog and new 36T 4th gear. Not very cheap as for me but not too expensive also. Yes. Now I have 35T cog on 4th gear.

Maybe it is worth to try short 4th with 23/68 primary?

I would fit the same as my Quattrini, 23/65 with 36 tooth 4th. It's not going to need to be split to change anything.

Thank for replies mates!

I need to think more about this. And I will riding last warm days with attention to gears/revs/speed.

I will be open cases anyway. But now I want to do all proper and not open it too soon again.

I have a Malossi 23/64 straight cut primary set with a 36t T5 4th gear on my Stella. It is just a little tall for my current setup (in my post signature), but I intended for the engine to grow into it as I keep modding. Once I get a better pipe, do some case work to port match and open up the intake, and put a bigger carb on it should be perfect.


Here's a pull I did to about 60mph indicated with it.

https://streamable.com/v8mlmr

Thanks Gummy!
Nice input.
After today ride I start to think that I don't need any changes in gear box.
But after your video I need to think again

The more I ride - the more I think

I really like how scooter runs now in more-or-less calm mode. If I want more dynamic - it gives me it. But. At the same time it seems that 1-3 gears is bit short from 7000 rpm and above. Seems like engine still have good power but acceleration is dulled...

I'm really confused - I don't want make mistake that cause one more cases opening.

And now it I think it's worth to put in 23/65 with short 4th.
Will look further...

I think that after a certain point, it's your ass that will give you the answer…as it sits in the seat. You won't really know unless you try it. And now that you have something to compare it to…

Worst case scenario, you hate it and put the old combo back in. Pick a time when you have time to tinker.

You could also get your GSF Dyno on if you really want to know what to do.

Ignore the numbers on the X Axis and instead look at where your power curve starts and stops.

Compare that to your gearing and it'll tell you whether your gears are aligned to the power curve or not.

If you change to this there is no need to split again. If 23/65 is too high, change the clutch cog to 22. This is then back very similar to 23/68.
Some 150s already have a short 4th. What's in yours already?

Something new for me. But I can't find where to download this app. Can you share some link if you have? 35T for sure. I checked.
Yes I understand about 23/65, 22/65 and 23/68. But in case with 23/68 and 22/65 it seems that I don't need short 4th.

23/65 might pull the long 4th. If you have a short 4th ready put it in. If you don't it could be ok. Your kit has more power than a stock 200. Probably more torque too.