Modern Vespa

Thanks! Now I can concentrate on my leaky tyres and rattly gear tube! Just took it through town and out for a 50km ride, and for the 5 minutes or so I was in 60kmh traffic it was holding around 230-250f. Smoothness was ok, not noticeably different but I wasn't paying so much attention to that.
Not sure about the 1mm, I guess that's half way between 1/8 and 1/2? If I was in 3rd it would pull hard but would take a bit more from 50-60 in 4th.

Doesn't seem like any immediate issue with the 1/4. What I was meaning about the 1mm, is that after holding steady for a while it should still respond to throttle. If lean it will make a little more carb noise and pull after a while. If rich it will gurgle and do nothing much without more.

It does feel like it pulls pretty cleanly once you crack that throttle now. Certainly you can tell the difference in that area between the X32 and the X13.

Some small updates, reed valve porting…

And some timing measurements taken. 1.3mm squish

Finally arrived around:

183 exhaust
129 transfer

Nice! Watch out for small children falling down that hole...

Which crank are you using again?

Just a SIP rotary crank 60mm, 127mm rod.

What exhaust, reed block and carb is planned for that?

SIP road 3.0, italkast double prism reeds and a PWK 30mm

129/183/27 perfect for that set up. Lots of torque. 80mph WOT, if necessary.
Looking forward to hearing it running.

Finally last mile.

Totally forgot where I left off, and what I'd posted.

Anyone dealing with the side panel hitting the spark plug boot with the 244 Quattrini kit?

Any solutions? The only one I can think of is grinding down the area on the panel the spark plug boot hits.

Oh and the fibreglass Tomas compo cowl is rubbish…

Doesn't fit properly and had to grind bits away for it to fit. Even then it rubs against the cylinder at certain points.

Biggest gripe is that it rubs against the frame. Those parts had to be cut away.

And it was super thin in some areas that it cracked.

Should've taken some photos.

Catching up on my fave two for one thread.

Weird there are so few options for cylinder cowl.

Is there a low profile spark plug boot u might be able to use?

Example:
https://www.amazon.com/Taylor-Cable-46051-Distributor-Terminal/dp/B000CQ6J4S

Looks like the marine world has some to offer.

NGK has some low profile red silicone caps…

For an expensive purpose made cowl, it truly is rubbish. I couldn't get mine to fit without some major twisting at the fan outlet casting. As the stock one had no such issues I used that. Anyone want to buy an almost new fancy Italian cowl?

The only place that hits (this is on a VBC) is the spark plug and cap...I was using the stock clip but it just pops off too easily when bumped. And I even bent a couple of plugs.
Now I'm using an NGK short plug (BR8ECM) and the type of plug boot that CM linked. No issues with that setup so far. That's only at full spring compression though.

108 don't forget to grind the head for your cht before you install it, it's tricky to get in!

Yeah, CM2 and Safis… I have it installed in the pic in black. Thought it was low profile enough, but still catches.

I think Ginch is onto something though… Re-read the Italian instructions… says to run a short plug (not the electro end…) like on the smallie. Those Italians seem to like the short type…

Still, that means I would need to grind the cowl…. Again… lol

This won't have a CHT… keeping it simple. Having it run properly is already a win.

The one I'm using is even shorter than the one in the Q instructions. Still fits (on the og cowl) with the right angle plug cap. Just.

Oh and btw, I ended up with an X2 needle as you had tipped way back. I tried an AV262 and that was the key to a nice smooth progression... meant the X13 needle was too lean. Worked my way richer until it wouldn't rev out on the X2 4th clip and came back one to third. So thanks for that!

That's great the needle has worked out.

Yeah the kit seems to run leaner than I expected. Time to get it jetted properly.

Finally buttoned up.

Italkast manifold is quite cool. Uses the latest Reed valve design which the egig 170 uses.

But it does point upwards a little too much. I'd still buy it over the vforce at the moment after riding the egig 170 now.

Little concerned a 262 is too small at higher rpm. AS atomisers jet in better on road scooters. Most likely the pilot jet is too rich confusing the progression. How you adjusting the mixture screw?

What reed is that?

At least the manifold doesn't stick up like some of the ones made for rotary valve. I know they say the carb will still work at a 40 degree angle (or something) but I'm sure they don't hold the same volume of fuel. The testing I did was all at 100 km/h, as a typical touring speed. When it wouldn't rev out with the highest clip I figured that is rich enough.
The pilot is a 52, so I'm thinking that it's not overly rich...?
Mainly I start out four turns and then slowly take half a turn at a time until it's running fastest. Then back out a touch.

Don't know to be honest… it's the one with 8 petals, that splits into 2 with the base made of rubber.

Probably all coming from the same supplier.

Hey 108, by short plug, do you mean we can get a long reach/thread plug, but with a shorter top half? If so, do you have an example part number? Cheers.

Oh yeah. They're nice. And a lot cheaper than V-Force from memory. The one recommended in the Quattrini instructions is the NGK B9EG, an even shorter one is the BR8ECM.

That's the one!

BR9ECM for me. Heat rating and resistor plug for electronic ignition.

But remember, needs a fat head spark plug cap.

All seems fine. My concern is with the high rpm running. AV262 may well be the correct atomiser for low/mid rpm but while running a needle with a 1.8mm tip, there is quite a restriction at the top.
What size did the main jet end up? I can calculate if its appropriate.

Finally, took it for a short spin.

Won't be doing any riding videos anytime soon though…

Awesome! Sounds great. Why no riding videos?

The main ended up at 140. That was prior to the atomiser change and didn't think to alter it... might look at that again on the weekend.

Needles. The info I have talks about the commonly used needles and says -
"For Dell'Orto PHBH, the leanest to richest needles are as follows :

Leanest - X12 - X7 - X13 - X2 - X25 - Richest"

Looking at the spec chart for the X needles, I realised I still don't understand. The X7 is 2.5mm in the straight part, 1.8mm at the tip and the taper is 20mm long.
The X2 is 2.5mm in the straight part, 1.8mm at the tip and the taper is 24mm long.
I just checked, and at full opening, I still have 4mm of taper that is hidden. If that was an X7 I'd just see the tip of the needle. Why isn't the X7 classed as richer? Surely it lets more fuel through at WOT? And since the angle of the taper is greater, more fuel should be available throughout the length of that taper?

maybe 6 months too late but here's some pics of a revised 200 cowl which fits no probs...

Still great to see! Got another point of reference.

I've have them on 232, 252 and 260

Longer the taper, the richer it is. So the x2 will be richer than the x7

The thinner the needle, the richer it is.

I always think of the needle as a plug. The larger in size it is (physical size), the leaner it is as it plugs up the space in the atomiser. The more space you have between the needle and atomiser, the richer the setup will be.

That's how I'm thinking as well. But... in my case at WOT the opening of the atomiser is partially blocked by the 1.92mm X2 needle. If it was the X7, it would only be the tip and the diameter would be 1.8mm due to the shorter taper. If it was the X12 (at 18mm), it would be fully open.
That says to me (with other things being equal) that a shorter taper unplugs the hole more for the same throttle opening.

There's something I'm not considering I think!

The needle lengths are the same length for x needles.

The only way you would get longer or shorter needles sticking out of the slide is via the clip setting which is not that much.

Are you measuring it with the slide and carb top installed so the spring pushes down on the slide and needle?

Remember that the main jet has a space for the needle to go into too.

That makes sense now.... that was the thing I didn't get! So obvious... duh! The longer tapers start opening earlier and are therefore richer. Thank you for that.

No worries!

140 MJ is still in the safe zone for the needle but seems really small. What main jet was wot spluttering at?

Thanks. I didn't know such a plug existed. My 225 has a centre plug and the side panel is a pain to get on and off.

Me neither, I've always seem to refer to B8ES or HS for older bikes and D series for Japanese bikes.

If it wasn't for the Egig 170 engine I don't think I'd know either.

There's so many sizes and variations I think most of us will never use, but they exist for some applications.