Modern Vespa

Awesome.

Don't sandblast the cases.

"If I were you" I'd do the migrate-over-new-crank and ride it with what you have now, like Greasy suggests. The stock Sprint V is a pretty torquey and solid bike.

You can do the go faster things without splitting the cases later.
But along with the new crank, replace the primary springs with more modern (double type) ones, in anticipation of possible go faster things.

Just degrease the cases and give them a scrub in hot soapy water. The oxidation won't hurt anything.

I really am like a foolish child trying to wander into traffic because it looks so fun and y'all are doing your best to keep me in line. I'll sneak out there eventually and get hit by a big rig and it'll be no one's fault but my own, just you wait!

So along the lines of using the existing cylinder, I have some noob questions.

- If I can feel some scoring along the cylinder wall, does that mean I need to rebore and go to the next size up? Or is some scoring is fine?

- When I get a new crank, should I get a new piston and rings as well? Or try and reuse my existing? Does the little end bearing need to be new or is that something I can try and re-use from my existing kit?

- Should I avoid any brand of crank? Or for this vanilla build maybe it won't matter much? (I think I saw somewhere recently where Mazzy cranks explode going a mere 35mph )

- Can I put a P-taper crank in so that I will have less of an issue fitting the VAPE? Or is that not necessary?

And in regards to the case:

I'm fine with not sandblasting, but should I lap the halves where they come together and where the cylinder seals? Wondering if oxidation would make for a dodgy seal. And if the studs are rusted, should I try and remove them and de-rust them, or just clean the threads that are showing enough to get a bolt on?

Thank you everyone.

it's okay, we'll all be here and try not to say "I told you so" it really depends. it ran before, and I seem to remember that your compression was in an acceptable range. I wouldn't necessarily sweat it. if it's scored enough to really catch a nail, then you might be okay with just a quick beer budget clean up on the cylinder and dressing the piston. maybe a hone and rings if it's a little past that, but without seeing it it's hard to say. only if your top end is roached. and if that's he case a performance top end is nearly the same price as an OE or a next over piston and a rebore. not particularly. a stock OE would be fine, and I always recommend a cut and flowed piece if you're doing it anyway. you can, but it's not entirely necessary. don't worry about the case halves. unless they're *really* beat up the most you may need to do is dress down some nicks with a file or paper. if the studs are super gross, you could pull them and wire wheel them. if you want to splash you could just buy new ones. but the studs don't actually contact anything so I wouldn't worry much about them besides the threads.

ultimately, this hinges on keeping this as stock as possible your first time out and thus eliminating as many possible problems or hangups.

you have a good idea of where you're going and have the right idea on the parts so I like this plan. I'm just concerned when you start introducing so many different variables that could potentially have issues with tuneability or runability that could leave you frustrated when it doesn't run right and wind up chasing your tail when it was something about the compatibility of x, y & z

but I think it's all something that can be overcome.

how bad were you reefing on the crank? think it's salvageable?

Also, where in the barrel makes a difference, with the acceptable depth of scoring dropping the closer to the top you get. For instance, I have a gouge in the Malossi 166 I had on my VBB for a while that you'd think would have left it dead on the road, but it's down at almost BDC, so no harm, no foul.

Fair question, but for your purposes, a Mazzy crank will be a good option. Pay the few extra bucks for the "finely balanced" version if it's in stock, but unless you're going to violate some laws of physics, that crank will probably outlast most of the other parts on your motor. I say yes. That's what I've done with my VBB and SprintV (both small-cone motors). I wouldn't remove them. You're more likely to create problems getting them in and out than it's worth, IMO. I'd leave them in place, just hit the threads with a wire wheel, maybe run a thread chaser down them if a nut won't hand turn onto them afterwards. Spray them with a little Ospho after you're finished to galvanize any fresh steel and you're good-to-go.

I had a number of years rebuilding VW engines when I started working on Vespa engines a year ago. I assumed I would have an easy time, because they were such simple engines. I still made a lot of mistakes and broke stuff.

Getting a close to stock build done ended up being a good place to start. A stock engine lets you set it up by the book and learns the basics with the least fuss. When you fire it up for the first time and it gets you down the road it will be plenty exciting. It never gets old.


For those about to rock, we salute you.
WTF, guys?

10-4 on all fronts, gents. I'll replace the crank but keep the rest of my top end for now. Two questions about the P taper crank:

- How will I know which P series cranks will fit in the VBC cases? Will I need a different seals or anything to make it work? Would something like this be the ticket? I guess I'm confused how to tell when something is the P taper and when it isn't. I also remember in Sausage's how-to videos, there was a bushing on the P200 crank he had that needed to be replaced, and I don't think my current crank has that, but do all P taper cranks have that bushing that will make things difficult to fit together?

- Are VAPE ignitions agnostic when it comes to the taper of your crank? Or do you have to buy the correct version that fits your crank? Are there adapters? I noticed on SM's site when you search "vape" a whole slew of slightly different ones come up.

And a question about my general electrical plan:

I'm planning for the system to be 12V AC, sans battery still. I have this harness and this regulator/rectifier. I have a 12V dual filament bulb for the tail light and a new non-sealed headlight unit that also takes the dual filament bulb. I was going to run everything AC except for LED bar-end turn signals (they're really small and cool looking, I just have to figure out a mounting solution but I'll get there) that I want to install and for these I was going to use the 12V DC out of the reg/rec. Does that plan make sense? Will I have to use the regulator that comes with the VAPE as well, or will the BGM unit be fine to replace that one?

Sorry for the endless questions. The VAPE is a pretty big hit to the pocketbook so I just want to make sure I get it right with the crank/ignition combo.


(Edit - new year, new avatar )

If your old points ignition works, I'd be tempted to keep it, skip the LED's and save a shit ton of money. For the expense, I don't think electronic ignition does anything special for a stock engine with static timing. My first scooter used points and I never had problems with it. I have run them on my VW too. Save you money, keep it simple and splash on a better top end when the time comes.

The crank you're looking for is this one with the 20/25 M12 fly side cone. It's not coincidentally the same crank I have in my SprintV motor.

I personally tend to go crazy on my ignitions, but that's just me being true to the rest of my build work. My main gripe with the 6V point is that the lights just...well...suck. I used to ride in the dark a lot (both going to and coming from work in the winter in Chicago) and the stock lighting was basically useless.

That's the same wiring harness I dropped into both my GL and my VBB. If you go with the Vape, you won't need a regulator, as it comes with one, so that's one less thing you need to buy. I'd personally also go with DC over AC since you're going LED. I've tried AC LED's in the past and found that none of them lasted nearly as well as the DC ones.

I run battery-less DC in both my VBB and Smallie. Other than the lights pulsing at idle, they work just fine. You can either add a very small battery or just up your idle speed a little (1,300 RPM's or so is enough) and that'll pretty well eliminate the flicker.

Which bar end signals are you looking at? I've considered them, but never gone there. Mounting them should be pretty simple, assuming they don't mind rotating.

He're my 4 cents:

- My points bikes have been more much more reliable electrically than the ones with CDIs.

- Variable ignition isn't going to make any difference on a stock engine.

However, since you're going to run bar end signals, you'll need DC (I have bar ends on one of my Supers). And since the variable ignition DC Vape is only about $10 more than the static version, you might as well go with the variable version.

If this is a US-spec Sprint, you may need to improvise a bit with the wiring to the ignition key or signal switch.

You have a few options here.

The P taper adapter cranks are designed to mount a P series 12v ignition. There are Vapes for either tapers now.

I have a static LF DC Vape on my time-warp USA market '74 VBC.
It's wonderful.
12v AC bulbs will work fine off DC, but the horn will need to be modified/replaced.

You could go 12v AC, shelve the BGM regulator, and get an inexpensive DC converter for the bar-ends. Connect to headlight power and tuck it behind in the headset. Maybe $15.

Btw I'd be surprised if you couldn't get your current wiring to work. Have you done a deep dive with your multimeter?
All wires disconnected. No bulbs or switches.

LF = Largeframe taper:

http://www.baritaliaclassics.com/catalog/product_info.php?products_id=874

Liking all the input, thanks all. All good points here (ha! See what I did there? Eh?...I'll see myself out )

One of the main reasons I wanted to get a vintage bike to start with was to learn how to work on it and restore it (slowly, and to the best of my noob ability at this point) so keeping it on the cheap isn't necessarily priority number one. Motorcycles are basically my only hobby so I'm ok with spending a little to make the bike "nicer" and more reliable. I'm not going for a hjo style resto (fire that motor already, we're waiting! ), I'm mainly looking to learn all about how to wrench on it, feel like I built it myself* and have something cool to ride around town. I feel like going with a more modern ignition will be a good learning experience installing it and hopefully make it more reliable when I just want it to start. Although I know CDI ≠ 100% bulletproof. Thanks for the crank recommendation. I'm still wrapping my head around all the options and how they're measured and what everything means and I didn't want to end up with a $200 paper weight. Since that is a 60mm stroke, will I need a 3mm spacer on the cylinder base?

And the bar end signals I went with are these ones from a place called MotoGadget. I also ordered this push button switch and their relay to make it all play nice. Not the cheapest option in the world (see above ) but they are very nice quality and I really like how low profile they are. Hopefully barely noticeable when not on. They do apparently have a forwards and backwards facing light cone that has an optimal degree of visibility which might get a little out of wack with both handlebars turning. This may be a totally bonkers idea but I'm thinking of fabricating a rod that runs through the center of the handle bar tube and have them mounted through a ball bearing or something that could allow them to stay stationary while the tube turns. Might be a terrible idea. I also might just let them spin and and set them for best viewing while the tubes are at the "stopped and in 1st gear waiting for a light" position. We'll see. I was thinking that I could keep the system AC and take the DC out from that BGM regulator for the LED signals? Am I missing something to where that wouldn't work? I downloaded the VAPE instructions and read the wiring diagram, which cleared a lot of that up for me (for now, until I go to actually do it and get confused again...). And yeah, for the whole bar end/switch set up I might pick up a moto battery and get it working on the bench before I try and get it on the bike. I have not gone full deep dive on the wiring harness yet but I have found some connections that don't seem to have continuity. It looks like someone spliced in some new wiring into the old wiring, as the wiring at the tail light and headlight seems much older than at the brake light switch. I'm a "well, if I'm going to do it, let's do it right" kind of person so I'm fine to replace the whole harness, then I know everything is new and connected properly. I'm sure I'll regret it when I can't get the wires routed properly or I muck something else up but hey... See, stuff like that is confusing because large frames can be two different tapers! At least their description says which taper it is. Some sites its harder to tell.


VBC cases are en route to me this week and I've ordered all the bearings/seals/cruciform I need. I think with this last crank + VAPE order (famous last words) I'll be good to start reassembly soon! Although I'm 100% sure CM will lap me on that front...

*with a lot of hand holding along the way from all y'all!

60mm stroke is +1.5mm up stroke and -1.5mm down stroke to get 3mm more stroke. In a perfect world you would need a 1.5mm spacer. With tolerances etc it's not a cookie cutter formula. For instance 1mm of squish could be considered ideal for performance. A motor may have a 3mm squish with a 57mm crank, a 60mm crank would change that to 1.5mm of squish so no spacer required. This is ignoring a lot of variables such as port timing, but you get the idea and gives you something to look up such as squish and two stroke port timing.

Gotcha. Thanks for the succinct explanation. I understand what squish and port timing are, but I definitely need some hands on experience to really understand how to dial them in correctly, because it seems like an adjustment to one affects the other. I bought this book a while back that I've been going through as well.

Timings can be fun to dial in, depends on exhaust, primary use etc.

I'm going to keep beating this into your head: the more variables you introduce to this build the higher the likelihood to have something go all pear shaped.

KISS

upgrade where necessary, don't unnecessarily upgrade.

is a new wiring harness a good idea, yes. is a vape a good idea, yes. is a performance top end a good idea, yes. but that's just it; they're good ideas. you don't need them to make the bike run and be rock solid.

avoid the pitfalls of wanting to do everything and make it Johnny kickass out of the gate, otherwise you'll just be mired in project creep.

Agree with Greasy. I bought a disassembled pile as my foray into vintage Vespas and have done everything at least twice. Some five times. Not recommended.

THIS^^^. I've never taken on more than one system, and that's on a running scooter. This is what I did:

Change points to Vape. Ride for a while.
Replace cables. Ride for a while
Get speedo working. Ride for a while.
Clean tank and install Ffftap. Ride for a while.
Clean carb. Ride for a while
Change exhaust. Rejet. Ride for a while.
New top end. Rejet. Ride for a while.
Etc, etc. Ride for a while.

One thing at a time. I still have stock wiring.

Yes yes, but at what point do I lose the support of the collective??

I fully admit I can get ahead of myself, but I'm just trying to get it road worthy.

My buddy Chris and I are constantly planning and going over all different facets of a scooter, and what to do. Then it all changes the very next hour,day, week. That's half the fun, to dream what to do and research how to do it.

Now, keep in mind, I've got three running scooters and he has three running scooters, and a forth we're working on now.

I'd never be without one running scooter - EVER.

My advice? - get the scooter running, bare bones basic, by hook or crook, THEN and only then, start making changes like cool blinkers, wiring harnesses, engine mods, etc.

OR -buy a known running scooter while you trick our your existing.

My two cents ..


Each one has a list of things I'd like to do, but they all run in the meantime

Appreciate the lookin' out, qas! I follow your thread and love seeing the stuff you guys are doing.

I definitely want to be running by spring, and I really want a P series bike at some point as well, but I told myself I won't get another one until this one is in a good spot. Just more motivation to keep the ball rolling with the Sprint. (I told my buddy back in Chicago to snag that PX150 on DotD so I hope he actually does it!)

I just want to get the bike to a good baseline. While it was technically running, it was never running correctly. Since I had to tear it down right from the start, it's almost like I bought a "scooter in a box". For me, something like a new wiring harness and Vape with relatively clear instructions on how to connect everything seems almost easier than trying to figure out whatever wiring situation I have going on now and fix it. I totally get what everyone is saying about not changing too many variables at once...but I feel like I'm almost starting from square one so why not update a little as I re-build? Everyone's gotta start somewhere. But we don't have to continue to beat the dead horse...

The info from all of you on this forum is insanely useful and I wouldn't have even gotten this far without it...the most quality info of any moto forum I've been a part of for sure. Also, like you said, I just like talking to you guys about scooter stuff because my wife just smiles and says "I'm glad you're excited about the scooter, dear". (Although she did have a line in our wedding vows about supporting my motorcycle addiction so...can't fault her completely )

VBC cases shipped out today. I'll post some pics when they land.

I have found this to be a really friendly forum where members enjoy spitballing about different engine options. There are many ways to run a bike and for any given component, there is one better, so you will get a lot of suggestions.

I have spent a lot of time going in circles and received many helpful suggestions. I never had the impression that anyone was ever insulted because I didn't go with THEIR suggestion.

Are you kidding? I'm insulted every time you ignore my suggestions!

Seriously, though, we all have our risk tolerances when it comes to both our overall tuning goals and also our pace of changes to achieve them.

What can't be emphasized enough is the importance of being able to execute correctly on the basics, first and foremost.

The best designed and set up motor in the world will leave you on the side of the road if it has an air leak. Knowing rich vs. lean vs. Just Right are critical to setting up a carb. Over- and under-torqued nuts will fail at the worst possible time. Skipping installing a split pin can land you in the hospital. Grease on the brake shoes will do the same. etc. etc. etc.

It's important to have all those basics not just learned, but made into fundamental habits. At the same time, you'll get to know the bike so that when something does get "off," you'll recognize it as abnormal, plus be able to troubleshoot and repair it.

Also, consider that the more highly tuned a bike, the more maintenance it needs--and that's a geometric curve. Race bikes get their motors fully rebuilt after a thousand miles or less, whereas a stock bike can run for tens of thousands of miles with nothing but oil changes and maybe the occasional new clutch corks.

I tried to skip over a lot of the basics and used to have a literal pyramid of blown up pistons and cylinders to show for it. While I've since taken my engine destruction game to the next level since then, I've also built a number of highly reliable, but also high performing (and high-costing) motors in the meantime.

Vespa tuning has taught me more about the inevitability of the Engineering Triangle ("Good, Fast, Cheap: Pick Two") than an entire technical career.

Right on! I'm down with the general motorcycle stuff and normal maintenance, as I've been riding for a long time. It's the engine building/tuning part that is new to me. But I'm totally fine to go slow and make mistakes (and let's face it, spend some dough) because I feel like that's going to happen no matter what components I try and use.

I remember when I got my first street bike in my early 20's and was learning anything and everything about riding. I had just changed my own oil and adjusted my chain and thought I was doing good. Noticed a little dirt/rust on my front rotor and wiped it off with a rag soaked in WD-40. That first stop sign after that was a butt puckering moment I'll never forget!

Fully expecting some "D'oh!" moments in this Vespa journey too!

I have stayed out of this thread as most on here have more experience on these motors than me. I have owned a few Vespas as well as another two I have now - a 2008 Stella and a dead 78 P200. It's easy to get all mixed up in the possibilities of what you can get out of these little Italian (and Indian) machines. Hours alone can be spent on the SIP site thinking what if.....in the end, I think you should consider what you are actually going to be using it for and what you want out of it. One machine may not be able to do everything - in town street racer as well as highway tourer, for example. More than a few guys on here have several machines to cover all their bases. Sort out what you really want to do with it and keep it simple as possible. You can build as you go, it may not be as efficient, but it will keep your sanity in check. My 2 cents.

This.

I have also pondered the what ifs, but I always come back to stock is about right for speed/power and reliable as all get out. I have a VBB that will pull wheelies (bought it that way) and I have to say, its just not as enjoyable to ride, and therefore gets little attention.

The difference between 55mph and 65mph is like $500-$1000 ouch. Also, I don't like going 65 on little wheels. At the end of the day its personal preference, but thats my $.02 My Bonneville is for freeways and power, scooter is for style. Lastly, the p200 gets used more than any of my 10 vehicles. Bone stock, pure fun.

https://scootnet2.net/index.php?do=showone&id=1111

bam. problem solved. add that BGM harness and you're set.

build the super motor out with all your parts on the slow boat while you cruise around with this bad boy. snap in the super motor when done and now you have a spare motor for another bike or when the super motor goes down.

That's a rock solid plan right there. If I weren't already more than a little extended on the smallie, I'd probably jump on that.

And when you want to go crazy on the tuning, the Stella motor is a great starting point with the native reed.

Always good to have a spare engine, if not a spare bike. That way, if you end up having to repair one and take the time to do it right while having another to ride.

Man, I was checking scootnet daily until I found those VBC cases too! Ah well. Scooter budget is stretched right now with the other stuff but maybe if it's still around in a couple weeks I'll think about it. Depends on how slow my current boat goes...

That's a different setup than my 2007, it has what appears to be an external pickup or trigger?

That's how it goes, once you dip your toe in. There are always options. I had started to rebuild the engine for my VBB when I bought 2 scooters. The VBC engine in it was plenty fun. It had a worn cruciform and sloppy third gear. Point is that I'm sure you will enjoy the stock VBC engine. It doesn't need to be really fast to be fun. Sometimes it's better to just focus and build what ya got. Those engines were pretty much bulletproof and sometimes that can be the best thing of all. I ran my 80's 150 at full throttle as much as I could.

Budget is important too. I would be highly bent out of shape if I dropped 4 bills on a slick kit and wrecked it. That's real (mad) money for me.

Yeah I totally agree that I should see what everything feels like stock-ish before I decide to do more. I want a high fun factor, and I'm old enough to know that speed, while part of it, isn't the only contributing attribute. In the little time that I got in the saddle before things went south, I loved the almost tractor feeling of just putting around! I'm sure the stock engine will be adequate for a while - especially if both of its case halves are sealed!

Some things...

You see what a stock Sprint can do in the video* below, from about 1:00 in until the Vespa conspirator goes into the phone booth. It's a '69+, even though the movie takes place in '63
*Day of the Jackal, 1973. Great movie.

Those turn signals are bonker$$$.
Big German market for bar ends, in order to meet their TUV regulations. I was going to suggest a $60 pair
Turn signals are tough to deal with on a vintage shifty, and if left on they can get you in big trouble. In my experience, hand gestures and ride behavior are safer, save for a few exceptions.

Go on a SoCal freeway on a Sprint and you will very likely be getting off at the next exit. There are a lot of speed maniacs here. Avoid their suggestions

You MAY feel a bit under-powered on major streets on a stock bike. Cars around you are in general very respectful toward vintage bikes, but there is some danger in being under-powered here in LA. You could chose bike friendly routes on Google maps and pretty much get anywhere you want to go -- also more lane split friendly.

Most important of all is the bike has to be made trustworthy enough to enjoy riding. Get it there 1st, before the doodads.
Basically, the whole bike has to be gone through -- one job at a time vs tearing it all apart.

Sidewalks only. Got it. I definitely need more than 6 mins of that movie! I'm intrigued... Yeah that's exactly where I want to be. Priority #1 is a running engine, then we'll reevaluate priority from there. I'm sure it'll take me a while, but I'm in no huge hurry as long as I'm making steady progress.

Speaking of engines, the VBC cases arrived yesterday. I'm really pleased with them. They are in great shape, minus a little rust and oxidation. I'll probably just hit them with the pressure washer, Evaporust the rusty bits, and call it a day.

I did notice that the fly side bushing that the crank bearing sits in has a hairline crack that goes halfway around the bearing. Would you guys run this or fix?


The perfectionist in me wants to fix it but, might be fine?

So that's what that should look like...

Castings seem to be improved on the Super engine in general

So long as that brass bushing is firmly in place, it's fine. Clean those puppies up and get 'em on the road

He keeps up with the BMW's in de Gaulle's motorcade
That movie's great, btw. Unfortunately, only 5 minutes with that Vespa.

I have another video for you.
Largeframe (in this case, VBB) motor assembly, with some key torque values that also apply to your VBC. It's not a perfect build video (the crank and bearings magically seat) but worth binge watching to aid build confidence.

Awesome, thanks Ray! Rebuild videos are my jam. I'm refreshing my memory on cush drive rebuilding with a video as we speak. Going to knock that out this weekend. I got the VSX rebuild kit with the dual springs for extra beefy-ness. Eyeballing it it seems like the plates are the same size, so I hope the springs will also fit.

Not to be totally pedantic, but those are Citroens. I'm pretty sure there weren't many BMW's in France twenty years after WW2.

Two of the assassins had MP-40's, which were assumably WW2 partisan surplus, along with a proper British Bren gun.