Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

So I just got the Ciao version of the Malossi 43mm kit from the treatsdom, and I'm wondering if anyone has followed the included instruction manual completely?

It says to cut the crank, drill the intake, and widen the rotary port. Also says I should run a 0.45mm point gap and use 95 octane.

The only part I'm really concerned about is cutting the crank, as I've heard horror stories of complete loss of power and the irreversible damage.

So, to anyone who has this kit, did you follow the instructions completely? Your results? I'm also interested to hear from anyone in general who's cut their vespa crank or anyone who's tried the anticipato crank compared to the og.

My setup: ciao, points case, 43 Malossi, techno circuit, sha 12 (might drill to 13). Currently in the pita process of splitting the case and removing old crank bearings.

I'll try to post some pics of the Malossi instruction manual later, but it's all in Italian so... Yeah.

Thanks MA!

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

If you are having a hard time splitting the cases, use more heat. I can see you went full budget in this build, but i would definitely say it's worth it to get a new crank, they are already cut. Don't need to go wild and buy a fancy one, but cheap out there and you may be regretting it. The new ones come pre cut, needle bearing and some are reenforced. While the o.g crank has brass bushings and is not gonna stand up to that much ripping, I have seen more than a few mopeds with stock cranks snap and send variator bit's everywhere.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

On my home computer I have the crank cutting instructions, when I get home I will post them for you. That being said, if you have the money I would spend it on a Mazzi Crank (either 10 or 12) so you only have to be concerned with installing the crank instead of cutting it as well. Even if you wanted to cut the OEM crank it's not hard to do, just a little time consuming. The Mazzi crank is built better and will definitely hold up to anything you will throw at it. It's also a needle bearing which is an improvement over stock plus it comes pre-cut for longer duration out of the box.

I use 87 octane in my 43mm Malossi Mazzi Crank setup and it works fine. I put 93 octane in my Tacoma and that's supercharged. There is no need for 95 octane in a moped.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Thanks for the link ninja! And yes, as deesal said, I went full cheap-o burrito on this one so no new crank for now :(

A new anticipato crank will come eventually, but for now I'm gonna try cutting the stocky. I've seen Arvid's crank cutting guide too but a lot of that forum gets lost in translation. So I'm gonna stick to the Malossi manual's suggestion of taking 10mm off open and 5mm off close.

I've got the cases apart finally and found that the bearing on the small case side was blown up with chunks of metal all over, I'm guessing this is why it wouldn't spin freely. Luckily the crank and cases are fine with only some minor nicks.

With some luck I should hopefully have my cases matched, intake opened, crank cut, and everything back together by the end of the day.

But for now, I'm having a helluva time trying to remove the old bearings.

Also, I just want to make sure but...

The crank spins clockwise right?

And which way does the piston port of the Malossi kit face?

Lastly, is there any aftermarket needle bearing that will fit the stock crank?

Thanks again guys! Any tips or pointers on vespa rebuilding would be appreciated!

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Here's the meat of the Malossi instructions: (sorry if it's not resized properly)

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

I have two stock cut crank motors and they blast. I had trouble with the bearings as well at first I didn’t know about the bearing puller. I removed them by putting a large flat head screwdriver under each bearing (while the crank was in my bench vise) and threw all my body weight on the screwdriver. This is an example of something NOT to do. Buy this Harbor freight bearing puller, I’ve also attached the video of a guy using the puller on a moped crank, the last link is for chamfering ports you need to do that as well, if you are kitting this bad boy chamfering is a must! Report back with some pictures I’d like to see your progress.

On the head of the Piston there should be an arrow or some type of indicator, That goes/points toward the exhaust spicket.

I don’t think there is a needle bearing for a stock crank

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

heres a scan of the Malossi 43mm base gasket if anyone needs it, I attached a full size scan so it should match after printing to use as a stencil..

trimmed it to match my cylinder, I had to take quite a bit off too. there should also be a chunk of gasket in between my sharpie marks, but for some reason it came precut all wrong, meaning its more case grinding than necessary.

thanks for the tips ninja! so I got the bearings off, but not much work done cuz I got lazy and it started raining. I'm still working on cutting the crank, its taking a while... I wish I had one of those flex cables for my dremel. oh yeah did I mention I'm doing every bit of work with a dremel and files? thats why I'm not sure about boring out the 12.12 SHA I have, I'd have to eyeball it lol

I'll try to snap a few pics along the way and maybe a first start video!


Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)


stock vespa cranks are amazing. did pinball with one.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Ok so all the major work is done! But...

I fucked up the install of the one and only crank seal! Lol FML. Went waaay too deep and it's totally rubbing on the bearing. Oh man, and I am just so close to being done!

So now I'm gonna try to fish it out with dental picks and pray, cuz I most definitely do not want to split the cases to get at it.

Anyway, I'll put some pics in the next post and hopefully continue this build if I manage to get that seal out safely. Wish me luck!

And any tips on getting out crank seals without smashing them to smithereens would be greatly appreciated!

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

In this pic you can see a stained part of the intake surface of the crank web

Crank is cut!

Cases marked and cut!

Intake opened and window widened!

And that's it so far! I've got the crank in the cases and failed at installing the crank seal, as I've said in my previous post.

More to come once I've sorted that seal!

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

When u yank out the seal put a new one in. Beautiful work. After my experiences I would suggest something like yamabond on the base gasket.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

I did all the crank cutting with one of those reinforced cutting/grinding wheels for dremel, and did the case matching with an old and really short carbide cutting bit. Both the wheel and bit are toast now!

For gaskets I usually like to install them dry, then check for leaks and goop it up only if necessary.

I've got some Q's for anyone that can answer:

-is the points cam collar thing supposed to fit on super tight, like press fit tight? Or should I sand down the id to get it to fit a little easier?

-on the right page of the Malossi manual I posted earlier it shows that the intake mating surface is supposed to be 30mm and the opening should be made to 20mm.

I opened my intake window to 18mm and the full surface is only 24mm. How far do you guys widen your intake window to?

-for my setup, assuming a 12.12 SHA for now, what size jet should I start out with? I'm in SoCal if sea level stuff really matters.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Also for anyone rebuilding a vespa engine, the CIF rebuild kit comes with 6202 and 6202/C3 bearings. I read through the vespa service manual and found that the C3 bearing goes on the output shaft/flywheel side and the regular one goes on the small end.

I was stuck for a while trying to find that info, so I hope it helps someone lol.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Jet suggestions for 43mm/65cc kits with 12.12 or 13.13 SHA?

I looked thorough the spreadsheet and saw generally 60-80... It's kinda all over the place.

Also, do you guys just lapp the decomp by hand with lapping compound?

And how do you get the dam exhaust to seal better?

First start coming up soon, I'll make a vid. Ordered 69-80 jets from treats, so I'll start off with 76?? sounds like a safe area..

Any vespa geniuses feel free to share your wealth of knowledge!

-thanks MA

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

high 60s/low 70s depending on pipe/elevation/weather

for the decomp, use lapping compound and spin it in a drill with a flathead bit.

for the exhaust, replace the shitty clamp bolt with a 1/4" stainless carriage bolt

also i hate to tell you, but for the malossi kit, everything flows through the piston. you wasted a lot of time and lost a lot of low end casematching it. on the bright side, your matching job looks great. if you apply that work ethic to a dr/polini kit, it would love you.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

With a 43mm kit I’ve ran from 60 to 72 main jet, I tried 73 but it wouldn’t hold an idle.

If you have a 13.13 I would run it but a 12.12 will run well with a stock intake case. If you bored the intake case out to 13mm then the 13.13 is a must.

I’m a Bravo head guy; Alex would know more about mounting the Ciao decomp then me.

Having a carriage bolt is a must to seal the exhaust.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Oh for the love of balls, I wish you would've said something sooner Alex. Oh swell, at least I tried to keep the cutting to a minimum. And the top two auxiliary transfers are pretty tiny and only go in bout a cm.

Anyways, thanks for all the tips guise! I'll have to find me some carriage bolt action and lower my jet too. Running it on 12.12 for now cuz it's what I got and I didn't want to prolong the anticipation.

And guess what chicken butt?!?

... Its a runnan!!! Yeahhhhh!!

Had to screw in that idle screw a far bit with the 75 jet.. But it did idle! Sorry no first start video, it was already dark out. And honestly I didn't expect it to run haha. So you guys have to look forward to a third start video tomorrow mornin. Be prepared to see the most badass ciao on mother earth.

Also, also, aslo, I didn't seem to need my decomp to start it, perhaps I have a major air leak.. Haven't had time to check all that yet. On my stock head there's a weird washer thing on the top right bolt to hold the end of the decomp cable, but it would jam against the new Malossi head. So I had to put it on top of the nut and use another nut to hold it down.

And how important is that front mount for the circuit pipes? I got a coupling nut with my techno circuit but no bolt to use with it, so its hanging off the exhaust port and rear baffle mount for now.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

What exactly is the difference between 6202 and 6202/c3.

I suspect it's real. I recently did two new cranks with bearings. Using the freezer / toaster oven technique. One was smooth as butter and the other the bearing hung up on the short end. Couldn't understand what was the cause. Now this c3 thing may be the reason. 50% chance of

Getting it right if u don't know better which maybe matches my experience.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Actually my short end bearing got caught up too, although I did that one second and also it doesn't have that long shaft to guide it down. And maybe cuz there's less material on the short end it causes it to heat up and expand faster, giving you less time. Just my opinion...

But I did notice that the C3 bearing had more "slack", like the bearing spun more freely than the regular one. If you pinch the center and spin it you should be able to tell which one is the C3 even if there's no markings on it.

So far I've started the ciao twice, 75 jet then 72, heat run then cool. Gonna do this a few more times till I feel I've got the jetting right and by then it should be broken in. Blasted pretty hard on the second run, though it was dark out and cold so it may be different in warmer weather. Got to about 295°F max temp, brought it up to about 40mph, didn't hold wot too long either.

When taking off there was some bogging and it got a bit more boggy right before hitting the pipe and smoothing out. Top end feels pretty good so I'm worried about going down more jet sizes for the bottom end. I might play with the slide angle and atomizer holes instead.

Has anyone done this kind of carb tuning on the SHA? There's not much for tuning in this carb, which is both good and bad, but it definitely sucks for trying to get that perfect air/fuel throughout the range.

Pretty lame how big carbs won't fit the ciao frame, I may try to make a really long intake and have it swing out to the side, though it'll still be limited by that intake size so it might be pointless going any bigger than 13.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

72 is the highest jet I have ever used with the malossi 43, and that was with a big pipe.

With a circuit, and those temps, you should probably drop down to 68-66.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

C3 I'd the bearing tolerance rating. They should always be c3 on both sides actually. It's the tolerance on the inside surfaces... the one s that the balls ride on so you wouldn't be able to tell the difference

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)


C=clearance. The lower the number, the high precision rating at high rpms

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Hmm.. Good to know^^^

Anyway, here's the belated "first start" video:

So I dropped to 69 jet. It's the lowest I had, but I'm gonna try the jet that came stock in the 12.12 clone, I think it might be a 64? Idk.

With the 69 jet I held WOT for a bit and got to 338°F max temp and about 40mph tops.

Anyone know what top speeds I should be seeing with this setup? And what temps should be considered safe or dangerous?

I feel like it's not reaching it's full potential.. I expected to get at least 50mph while keeping decent low end. I had a Puch polini previously on a single speed e50 engine that did 55 while killing the clutch and running so hot that it soft seized twice.. But that's a different story.. Maybe 40mph is a more "reliable" speed anyway?

I am planning on doing the variated swap, but that's for later times with more money. For now I'm gonna try to get more top end out of this single-speed setup.

*can't seem to embed the vid, if someone can help with that I'd appreciate it (edited)

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

drop the jet to 66 and go from there

i warned you about the low end on the kit that gets killed by matching

what pulley do you have? what gears? hows the belt tension? whats springs are in your clutch?

vespa tecno circuits are junk. if you want a cheap circuit, get a proma. theres only a handful of good pipes on vespas so pick from these:


polini top one

simo calibratta

gianelli fire

those are the only pipes i would reccommend and are still available.

i love my single speed vespas, when i dial em in they have great low end and havea higher top speed than a variated bike.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

I like the green on green color match.

I’d get a high flow air filter on this bad boy

I prefer a varaited set up but if you want more top end with a single speed you will need to get a smaller pulley. I personally would like to see a Top One pipe once Treatland gets them back in stock on this Ciao. I have the Proma on a bunch of my Grandes and they are a nice pipe, The Tecno isn’t the best performance pipe but it’s a hell of a lot better than the stock chrome one.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Some people brag about how they get high forties or fifty on a Vespa but hey you are in the magical sweet 40 club!!! I say take that and smile. 338 wot at forty while wherever u r in early spring sounds very nice. As in marvelous. The bog .... It's going to be hard to tune it out. You could go down on your point gap to advance your timing vs down jetting and yes both are going to

Raise those temps. I doubt that playing with the slide angle is going to do it. Will one of those crazy holes in the slide do something?? Well if you think you can drill a hole away from the Venturi effect that will lean out the 1/4 -3/4 slide position , I think it's not going to fly but hey grab a spare slide and

Try it.

I have a variated grande that with the Mallosi 43 hit 43!! Until I got crazy and tried to adapt a Kinetic cdi. I'm back to point but went on extended vacation with Tyler's 46 mm motor that I built up.

As for pipes maybe the techno is junk. But if you realize that header length of all circuit Vespa pipes is constrained by the issues of pedal clearance I'm not sure how a techno vs whatever proma can be that important. I also have the simo but hand fabbed by someone that made a beauty. But again it looks so cool and has a sweet sound but as to a major difference in proformance: I don't see it.

I vote for riding that bike for a few months and actually just enjoying it. Do you really want to go faster on a ciao frame ????

Lastly one of these days graham if he gets the time will offer some subframe a for all you crazies( me too I guess) that want big carbs. Yes if that little space could fit say a phbg it would simplify tuning.

Dude congratulations on a superbe job.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

ciao frames are awesome. i will hear no different. anyone who doesnt like their ciao frame can send it to me

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

Charlie Mccharles /

Lol I agree that ciao frames are awesome, I would maybe want to try extending the frame a couple inches to fit a nice fat carb... But hey, I'm no welder and I don't know much about structural integrity, but I don't think I can do any worse than stock ciao haha.

I thought the techno and the proma looked pretty identical, so I went with the cheaper.. as I did with the entire build... But really I thought that the only downside of the techno was the built in restrictor? I hope to one day have a calibratta, but until then I got what I got.

Alex, the pulley, clutch springs, gears, all stock. I didn't think you could change the internal gearing in the single speed trans? Belt tension is good, no slip at all. I tried putting on the stock air filter with a couple holes drilled but it made no power, so I take that as I'm super rich. I'm gonna make an order for 60's range jets and other essentials like a new throttle.

Ninja, glad you like the pedals! Walmart special! Lololol.

So yeah, once I get the jetting dialed in I'm probably gonna try losing the head gasket and take a few mm off the head for more compression. It just seems way too easy to start ATM, like I don't even need the decomp and it starts first crank. And I don't have the crazy idle that comes with air leaks, so I don't think I have one, at least not a major one..

Anyway, I'm getting ahead of myself, I should just be happy the damn thing is running..... But this is mopeds, and you always want more, until you break everything, and have nothing.

Re: Vespa Malossi 43mm / 65cc kit instructions (crank cutting)

get yourself some clutch springs( i like polini blue springs) and drill nice big holes through your shoes

i like the 80mm pulleys gearing on 7:1 gears personally.

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