Modern Vespa

Yeah, cutting together the video, I realized how much I need to stop and just go back to start for setting up the carb.

Go back to a 170 main, maybe less once other settings are closer, then figure out needle diameter and go from there. That's all 8. I'll open it up and see if I can figure out what's going on, but probably not for a week or so, unfortunately.

Ah suck man… was hoping you only installed 6.

One thing I found out which helped set the clutch cable tension was pulling the clutch lever at the handlebar, then constantly kicking it over with the kickstart pedal and slowly releasing the clutch lever until the Kickstarter starts to turn over the engine.

The cable is adjusted so it's kicking over the engine, when the clutch lever is at 40-50% (lever pulled all the way to the grip being 100%)

Seems to have helped with clutch engagement for me… wonder if you have the clutch engaged constantly at the moment…

Hope you get to the garage soon… loving the blue painters tape holding stuff down.

CM you said Grimeca but the link is to the Crimaz... which one did you get?

For the master cylinder? I got the Crimaz. I posted a photo of it back a page or so.

Here's some homework for how I begin.
First thing check the float weight and level are acceptable for what is being set up. If this is found to be wrong it's back to zero again later on.
Next take out the main jet. Having one in just gets you lost in the Bermuda triangle.
Mark 1/4 increments on the throttle.
Set the airscrew/pilot jet to end up at 1.5 turns
Set the diameter. Hold 3/16 throttle parked somewhere you can be noisy. Decrease the diameter until max rpm drops. Increase diameter a little until it revs out correctly.
Careful it doesn't jump into gear, believe me it's never good.

Ah so this is when it gets interesting…

So for my pwk28, I called the guys at Scooter & Service about jetting it. And Wolle and co said the air mixture should be around 2.5 turn out.

I was like: "are you sure?? That sounds like a lot!!"

And they said yup, give or take 1/8 turn.

I asked if it would be similar with the Airstriker, and they said yes.

I trust them, as they sell the carbs, they have dyno videos and basically churn out a Vespa every other day at their workshop!!

My pwk28 runs like a dream now…

And with the PHBH, although it's a fuel screw (which is a little different), its 3.5 turns out! I asked about 6 people who run the same engine (including the creator himself…) and they said 3.5 turns!!

I was running 1.5 turns with the malossi 210.

Just go to show the variations in setup…

Did you notice I said begin? More turns on an airscrew, if set correctly, means the pilot jet is bigger. Without a main jet and a full rich pilot jet it is extremely difficult to set the diameter.
Nice you have a direct line to our creator. Is that a bit like "Constantine"?

This I can work with. I'll have to decide if I want to annoy the neighbors or go through the effort of heading over to an industrial area, but I can work with this.

Thanks, Jack! Oh, I know ALL ABOUT that.

A bit like that, but I use a mobile phone. The guys in Germany and Italy usually answer when you dial the relevant number and ask nicely.

Can't hurt to ask the guys who make the parts in the first place and who write the instructions.

I totally agree that having a rich pilot will leave you in no man's land.

But I'm just pointing out that ending up 1.5 turns out on the air mixture screw might not be your end point.

Yes agreed.........however, depends what style of jetting is required. For sprint racing, fastest might be 3.5 turns. Commuting economy is better at 1 turn.
For most home fiddlers, if it's set correctly and that's properly correctly to the pilot size by ear, then ends up anywhere between 1 and 3 turns. It will do just fine.

So I did two things tonight...

First off, I replaced the clutch with a Fabbri FB45 clutch. Mostly. My primary drive basket lacks the wide opening for the included plates, so I used a plates out of my other Egig one-finger (the one for a triangular shaft) and 8 large + 4 small springs. It's stiffer than the egig, but I think it's still lighter than my GL.

The old plates were THRASHED. The reason they wouldn't quit slipping is because the corks were basically gone.

That was a huge PITA. Maybe I'm doing it wrong, but I think that removing and installing the smallie clutch may be my least favorite scooter task, at least right now.

And words cannot describe how pissed I was when I realized the plates didn't fit my drive basket.

Then, I swapped out the Polini PWK34 for a Keihin Airstriker 36. Even with stock jetting, it's better than the PWK ever was. Lots more low end power, feels like more torque (but that could just be because the PWK was set up so bad), and I think more power in total. It was dark and rainy when I did my test ride so I didn't really push it, but my initial instinct (and not a little bit of confirmation bias, I'm sure) is that it was a solid upgrade.

The front disc is due to arrive tomorrow, so that will go on over the weekend. And at that point, the big parts of the project will be getting close to finished until I decide to tackle the paint and body work.


Expensive, but hopefully worth it.

Noooooooooooo!!!!!

Thrashed. But I had fun getting them that way.

Woah, sucks ( and slightly odd…) that the fabbri plates doesnt fit a stock primary basket. Good to know for future reference.

Building another smallframe at the moment, but the fabbri clutch seems to fit the SIP/DRT primary.

If I remember right, seems pretty stock. I see if I can get a photo of it next few days.

You're still running on a helical primary? The primary basket has started to get those hit marks that mine had… might not last too long with your engine tuned…

Wondering if those plates got hammered because of the old clutch cover? That it wasn't fully disengaging?

Those look like toast… like really burnt toast…

Surprised you didn't stick with the one finger clutch and just swap out the plates?

Nope, still the one thing I dislike the most is taking off the exhaust… every time anything needs doing, the exhaust has to come off…

Closely followed by the clutch… but more like the clutch cover actually

That doesn't look right. So that is the wider primary basket opening that allows you to remove the small primary gear? Must be a VMA1 thing. I guess I always went straight to the DRT primaries, but I thought they used a pattern primary basket.

First time I see a basket without the bigger window for the crank cog. Even the cheap F.A. primaries come with it...

The basket is the original VMA1T basket. Assuming I kill it with power, I'll switch over to a straight cut primary and basket at that time and get one with the wide slot in it. I'm not in a huge hurry to split the cases right now, but if I have to do it, I have to do it.

The plates on the fabbri are really nice, some sort of synthetic material. Much nicer than regular corks, maybe the same material as on CR-80 plates. I'll have to see how the corks from the one-finger do, but I think part of the problem was the slipping under power rather than a too-tight cable.

And what's really crazy is that those plates have only been in use for two months!

This thing is definitely next-level power, with both the good and the bad that brings with it.

And 108, removing the exhaust is nothing for me. One bolt and two springs. Takes literally under two minutes. It definitely seems dumb that you have to remove the brake plate to get at the clutch, though. Seems like that's something that could be reworked pretty easily since it's mostly just the two longer cover bolts not clearing the brake plate.

In other news, the front disc setup arrived.

I weighed it at 8.5 lbs and other than a tiny bit of rubbing of the caliper on the disc, it's all really smooth. It'll go on probably over the weekend, but maybe sooner if it refuses to stop raining.

Anyone know what the recommended routing for the brake line is? Down through the fork, same as the cable, or something different?

Disc setup looks awesome!

Looking forward to seeing what you think of the stopping power vs drum.

For the hose routing, I was imagining 99% the same as the drum cable. Maybe outside of the fork rather than inside though.

Nah for the exhaust, it's easy as, but doesn't make it any more pleasant. It's rarely at the same angle and position as before, when you reinstall it. Just gives me the nerves that it's wearing away with all the pulling twisting etc…

This scooter must be your favorite. The others will get jealous.

Oh my. That disc makes me want to build something that needs to stop.

I did a little research and the consensus seems to be to run it down the fork, so I'll be going that route. I can't imagine it being any worse than the drum, which is better only when compared to putting my feet down and dragging them Flintstones-style. I won't lie. It's definitely getting all the love and attention these days. It seems like a really solid piece of kit.

I had to order a banjo bolt and really need a different banjo, but the Spiegler fitting seems to be semi-proprietary, so it's hard to know for sure and I don't really feel like either ordering from SIP and paying more than the price of the fitting in shipping or guessing and winding up with useless spares.

Anything in stock here?

https://www.thatscootershop.com/onlineshop/custom-brake-line-spiegler-vespa-px-amp-stella

I'll have to give Lee a call next week and ask him if he can get me just parts. Alternately, I could do it via SM's SIP order service. I just ordered a new piston for the Smallie that way. I'd like to find a fast option, because as it is, I'll probably be rolling with something really hackish up on the headset in the meantime.

I'm excited for your new disc brake! As to hose routing, it's all about what you want. I've used all three options for routed my hydro hoses...running the hose outside the fork and up through next to the steering column (just like the PX/Stella disc.

The whole hose located completely outside of the frame (track bike style).

Or running the hose inside the fork. I think running the hose inside the fork aesthetically looks the best, but that's just my personal opinion. The only down side to routing it inside the fork is that you have to remove the hose to drop the fork. But if you're doing a scooter build, then you wouldn't really have to go back and drop the fork ever again...unless you have to. You're also limited to what sort of hydro hoses you can use. You can assemble some Aeroquip lines. Another option (that you found) is the Spiegler. With my rusty VB1, i'll probably choose Spieger this time, and then route the hose through the fork.

Never been able to install a Spiegler set properly on a Vespa.

Either the hose has been too long, or I couldn't get it to go through the fork, or both.

Unfortunately, not road legal, but always had to build custom hoses to get things to line up and work properly.

it's supposed to start raining soon and continue all afternoon into the evening, so I got out this morning and tried to get some footage. I got some decent fast pass video, but I somehow managed to put the GoPro in timelapse mode, so that's pretty useless for my purposes. Meh.

I also captured a GSF Dyno run, but I don't believe it, so I'll keep that to myself. the curve looks right, but the power is too high. The peak RPM's have bumped up from right at 10,000 to 12,000, though, and stays in the power band all the way up there. I was doing 57 MPH in second gear!

I'm continuing to fight with my clutch a little. Either it wants to drag a tiny bit when in gear or slip under power. I know I'm using improvised plates, but it's still freakin' irritating.

Tomorrow is going to be Disc Brake Day, I think. I may wind up with the house in some stupid routing out the master cylinder and then have to re-bleed the lines when the 90 degree adapter I ordered shows up this week, but I'd rather do that than have to wait until next weekend to do the whole project.

A little video from earlier today. Bike is sounding much better.

I'm starting to learn Keyframes, for better or worse...

Love dat braaaaap!

Man that clutch is screaming for mercy

That's also the reason for too high hp numbers. Revs just go up without working while GSF Dyno thinks there is zero slippage.

What oil do you use in your gearbox?

+1 Clutch is slipping a lot. Not putting the power to the pavement... just turning the horsepower into heat on the clutch plates

The engine sound +Doppler effect must have crushed that poor cyclist.

That actually makes perfect sense why I'd have such a nice looking curve, but such a high HP number (it was 55 HP peak, for those who are wondering).

I run a 30W non-detergent synthetic. Same stuff I've run in all my motors for 15+ years now Yeah, it's really obvious on the second pass in the video. I limped it home, not quite sure where to go from here--it either slips when I ride it or drags when sitting in gear. I guess I'll take dragging and just deal. He seemed none-too-thrilled. What did he expect riding his bike through the middle of my test track, though?

Today I fitted the disc brake. Cable is run, but waiting on the banjo nut to arrive so I can semi-finish the install (I'm going to build it without the 90 degree fitting on the master cylinder to get the ball rolling. I just wish it would show up before it gets too dark.

So the good news is that the disc is on.

The install required a little bit of fighting (and Dremeling), but nothing major. I had to grind back the swingarm a little bit to get the banjo bolt on the caliper, along with loosening the mount bolts and removing the hub nut. The good news is that after I did that, the tiny bit of rubbing I'd noticed previously is completely gone.

I used the speedo cable hole to run the brake line. I had to grind it out some with the Dremel, but after I did that, it fed through without a hitch.

The Crimaz master cylinder setup, however, was a bit of a disappointment. First, the holes didn't match the mirror holes in my headset, so I had to take the mounting bracket off to drill a hole in it. Which was obscured by the master cylinder, of course, so I had to mount the bracket, then install the master cylinder back onto it.

I hooked it all up and started filling/bleeding the brakes...and filling and bleeding...and filling and bleeding...and eventually, I got sick of trying and let it go for the night. The brake works. The fluid rises in a tube on the bleeder, so I know the system has at least a little pressure. But...the caliper barely moves enough to rub the disc. Definitely not going to stop anything like that.

So right now, I have the best looking, worst looking front brake I've ever owned. Go figure.

Anyone have any advice for where to go from here?

In clutch news, I adjusted the clutch waaaay back in and all now seems to be well. I'm putting it down to slipping causing heat causing swelling. I'll continue to watch it closely, not that it's going to see any use until I get the front brake going.


disc brake porn

I'm ready for my close up, Mr. DeMille

I have some expertise in these matters...

You are fighting more than one thing.
The combo will frustrate you to no end - ask me how I know...
You gotta beat each one out.

- You want to reverse bleed.
- The air is hiding in the high spots.

Here is what I do.
1. Must reverse bleed. Need at least 200ml syringe - because otherwise you will introduce more bubbles as you keep having to refill the syringe - so min 200 ml is needed. https://www.amazon.com/Syringes-Dispensing-Scientific-Watering-Refilling/dp/B07688FXVF/ref=sr_1_4?crid=ZXFOTGBHHVAX&keywords=large+volume+syringe&qid=1670813194&sprefix=large+volume+syringe%2Caps%2C188&sr=8-4

2. There is likely air hiding in the caliber. You are going to hate this. Can you take the caliper off - raise the front end - and hang the caliper down while reverse bleeding? It may be only way to remove stubborn air.

3. There is likely air hiding in headset or near master. Trick here is to lean bike SO FAR OVER - that you are basically making the horizontal length of brake hose sit more vertically. the point that it turns from horizontal to vertical inside the headset is a likely air holder - so tilt that thing far enough that you create as steep a grade as possible for the brake line. the more vertical it is - the easier it gives up the bubbles. I can see that the line goes UPHILL after exiting the master. You need that to be down hill. Pro tip - take the master off so you can put it up above the handlebar and create more vertical condition for bleeding. Those bubbles will just hang in that area.

4. While reverse bleeding - beet the brake line with an open end wrench - RIGHT WHERE THE HIGH SPOTS ARE. it makes a difference

Good luck...

I already started down the road of looking at how to deal with air bubbles, including in the caliper. There's no way it's coming off, but this is a rat smallie we're talking about. I can flip it around any way that might make sense.

I already ordered those syringes. They'll arrive on Tuesday--same day as the 90 degree fitting to fix the loop up by the master cylinder, so no point in worrying about it too much until then.

I was getting basically nothing for the longest time, so I hooked up my vacuum pump to the bleeder and was able to pull fluid & several bubbles out that way, but obviously not all of them.

I worried a little that getting the brake fluid in and bubble-free would suck, but I didn't anticipate this level of sucking. Oh, well.

Thanks, CM2!

Ha!
Ok - well - you might need to turn it up wheel style on its back wheel - but suspect you will slay this monster with where you are heading.

x2 on everything that Charlie said. Plus i also like to tap the side of the caliper, hose, and M/C with the plastic end of a screwdriver. It helps to dislodge those sticky air bubbles from nooks and crannies.

Since the brake issue seems to be covered, I'll chime in on the clutch.

When you turn plenty of power into heat inside your clutch, it has to go somewhere. That somewhere in addition to oil is the intermediate discs which tend to warp when they get too hot. This is likely the reason for drag when clutch is pulled in.

I spent a little time in the workshop this evening bleeding the brakes. I made a lot of progress, but still more work to do. It's now as the "almost as good as a drum" level of performance, so I assume I'm on the right track.

First, I stood the bike up on its tail to get the caliper as the highest point in the system. I'd pump the caliper while I used a syringe to put vacuum on the bleeder. That got a lot of air out, but not all of it.

Next, I laid it over on its side to get the entire system level and worked on it some more. that also got a fair amount of air out. Eventually, nothing more was coming out, so I stood it up and tried a test ride, which is how I know it's not yet as good as a drum.

The 90-degree fitting for the master cylinder and (much) larger syringes arrive tomorrow, so I'm leaving it for now, but I feel like I have a much better handle on what needs to happen than I did.

So not yet success, but at least I made progress.

Larger syringe for the win!
Almost impossible not to get a bubble in the damn thing when refilling in middle of process.
I can't stress enough - every turn is a trap - and every NEAR horizontal is like traffic in Los Angeles. The bubbles CAN be removed - but they just CRAWL along in those areas.

Try and be methodical and chase them from one end to the other.
Making me rethink taking off my master to repaint...

The disc kit looks great on the bike!!!! This is definitely looking like a great build, with the gauges on the bars and all.

That's exactly how it would route the brake line.

Not sure if I'd repaint at this point! Looks pretty good.

For the brake bleeding, yeah reverse bleeding via a 150ml syringe or bigger is the way to go.

I remember literally using 8 hours to bleed and brakes, and still felt like sponge. Used the syringe and it's done in 15mins. It's just extra tedious for new empty brake systems. Another method is to bleed over 3 days. Seems to give the a chance for the air to ride to the top (that's with a bleed valve at the master cylinder though)

There will be a ton of air in the master cylinder if the reverse bleed fluid doesn't pass through to the reservoir. Gotta make sure there's bubbles coming out.

Oh for the clutch. Something to note, the one finger and fabrri clutches need at least 400ml of gear oil.

I think it might have something to do with the clutch plates being more than stock and more compact. To be honest, after 250ml gets flung around, there's not much left sat in the engine.

Something extra annoying as the fill hole gets full at around 250ml. So have to lay the engine down, fill via the clutch cover etc…