Modern Vespa

You're welcome Ginch
How is it to use rotary intake with 24mm carb( no reed use)
And with these kit do i need lighter flywheel?

Iknow the polini cast can run stock flywheel,
Read that the pinasco must not have a flywheel heavyer than 1.4 ( zura pdf file for cylinder kit)

Never had much interest in smallframe scooter until i got my own couple of years ago, but never used it.
But now started now to gain interested and wanna build a fun relaible scooter

But then u start searching , and i find it hard to decide
What iam used to from T5 either malossi or polini, pinasco and only one kit per brand.
But now it mind fudging my head
And every body saying go polini, but i want the alloy version.
But then the parmakit ecv is cheaper, trying to find what difference between of those kits are with power ect,
Polini alloy 2 piston ring and parma 1 ring.
There is just so much to get into.
But i love it.

While I try not to send people away from MV, the guys at the proboards smallframe Vespa forum are awesome on the techie side of the small engines.

http://vespasmallframeforum.proboards.com/

There isn't a ton of traffic but you will get good answers if you have technical questions. We have far less smallframe guys on MV than over there.

I am a member there and on German scooter forum.
Like to hang out on both forums and read.

What exhaust were you planning on using? That might be the limiting factor that helps you pick a top end.

A friend had an old simonini down forward, that i got
But thinking lth road/midrange, vsp road or somthing.
Have side toolbox so my options are limited. Hade a look at the sip banana and the new bgm banan,
Thinking not very aggressive but stil useable

I used a Simonini, in a 100 sport with a battery, it barely fit, but I like how it sounds. I hope it works well with the Pinasco top end.

Is your toolbox like the 100 sport or the ET3 smaller door style? I think the latter has more room for exhaust choices. For the former, yeah the Polini snail (or similar), banana style exhausts, or the down and forward Simonini seem to be about the extent of what works, short of cutting.

Just took the motor apart. And I need so much parts then imagined. When Wil I ever learn.
So now
I finally decided for what engine build.
Maby I should start my own thread with pics.

Sounds like it might be a 10 page thread...
Good luck!

A two year bump!

I got bored one afternoon last week so I pressure washed the heck out of my PK, then dropped the engine and had it stripped down in a few hours. I'm doing a full engine rebuild, and ordered a boat load of parts for it. I ended up choosing a Parmakit 130 ECV Challenger kit. Its porting is biased for road touring. I ordered up a bunch more parts too, but in the whirlwind of ordering, I can't remember the parts numbers I went with. All I know is that I blew the budget twice over with just the first order...ugh! Both the stock 1st gear and shifter were worn, but somehow all the other gears were 100% with zero nicks in them. The SIP order might show up this week. I'm planning on going fairly tame in the power department, but at the same time I'm going to be using higher quality parts for the build. The goal is to have a clutch and transmission that can easily handle a mild cylinder kit. It should make the whole engine a bit more reliable. The other goal is to keep it somewhat fuel efficient, so I'm going to try to keep the stock 20 carb and a simple Sito exhaust.

Whenever I look at Parmakit stuff I get a headache... there is just so many versions!! So which version did you decide on? Quite a number seem to have the split exhaust ports so I imagine they are meant for high revving applications.
The one that did look very interesting is the 175 kit... it's a "66" meaning it's a 66mm bore with no skirt.

https://www.ebay.com/itm/57930-00-Cylinder-175cc-66-Parmakit-W-Force-Sixty-Six-Inch-Vespa-Pk-hp-R-L-50/392520537956?epid=10024591258&hash=item5b640c1764:g:hNIAAOSw-pNb3DE0

One of my riding friends, who is recently here from Sardinia and therefore grew up with smallframes, has a low opinion of Parmakit. He said "The best kit I ever had was the first series of Parmakit, both cylinder inducted, or case inducted, but then they released other versions and fucked them up." I'm really not sure specifically what's wrong with them, but the reputation of their pistons is not very good. I've seen it mentioned a number of times on the GSF.
Still, they look awesome and I'd love to try one!

Yes, they have a confusing amount of kits! I went with a simple non-reed cylinder kit. https://www.sip-scootershop.com/en/products/racing+cylinder+parmakit+tou_75041920
I was going back and forth about using one of their reed kits, but it requires cutting the sheet metal to get it to fit the PK scooters, so i passed on it. I wasn't opposed to spending a little bit more money on a different kit, but i'm not after lots of HP...AND that there are so many SF kits out there, it was almost like throwing a dart at a map to decide what to get. Pretty much all SF kits out there are advertised for racing and high HP, and that's not what i wanted. When my 125XL was stock, the top speed was about 55pmh (with no headwinds or hills) when cruising on the highway. I'm mainly after more torque so that i can keep that speed up for the hills. I'm rarely over at the GSF since i keep forgetting that it exists!

I just found this thread over at the GSF https://www.germanscooterforum.de/topic/346160-parmakit-ecv-was-kann-er/

if you want to keep your speed on hills make sure to attack the gearing by way of a DRT short 4th tree or depending on your exhaust a short 3rd/4th tree. well worth the effort, the stock 4th is too big of a gap from 3rd.

I did invest into gearing as well John! I think i went with the Crimaz tree? I also converted over to straight cut gears too. I previously installed a short DRT fourth gear years ago (for use with the stock cylinder and exhaust), but i was recommended to change it back to the stock 4th, then install one of those DRT trees because the tamper on their shaft's are better suited for more power. The gearing is slightly different between the DRT and Crimaz trees, but i was liking the ratio better on the Crimaz. Funny thing, i think each individual ancillary tuning part was more expensive than the cylinder kit itself! I knew it wasn't going to be cheap, but all of those components sure do add up fast! I was actually eyeballing those 5 speed kits too, but that was way out of my league. Maybe if my frame was REALLY nice or if i was planning on racing the scooter, but as is, i passed on that option right quick! A DRT crank and some semi-fancy clutch was ordered as well, but i can't remember the part numbers. I'll take some pictures of them after i pick up the parts.

This whole build was spurred on my the fact that the scooter was jumping out of 4th, the clutch was slipping at all RPMs, and the carb needle was leaking. All that was probably just a $200 fix, but one thing led to another, and boom..one empty wallet!

isn't that how it always goes? you need a carb float and you end up with a FALC engine or somesuch...

gearing is often forgotten, glad you have sorted it already. IMO it's more important than how nuts you go on the top end because if you can't drive where you make the power then you just wasted your money.

I got some go-fast parts last week! Now it's time to start getting everything sorted.

I ended up going with a 53mm long stroke DRT crankshaft. The outside diameter of the fly side web is too big to fit in the case, so I had to get it milled out at a machine shop.

The SIP description of the crank says that it has a highly polished connecting rod...something must have got lost in translation.

...so I ended up taping up the crank and sanded and polished as much of it as I could.

LOTS of material from the cases needs to be removed just to match the flow of the ports.

After opening up the ports a bit, and flowing them to the cases, there isn't much sealing surface left for the cylinder. In one area, I have about 2mm of a sealing area left...which is enough for a good seal, but I wanted a foolproof great sealing area. I took my cases to another machine shop, and they decked the top of the cases down .50mm. Given that the 53mm long stroke crank that I bought comes with a 1mm aluminum base gasket, I should be able to simply install a 1.5mm base gasket to bring it back to where it's supposed to be.

And after the machine shop did their work. They were having a slow afternoon, so the father son duo started on it right away. About 40 minutes later I had the cases back!





Last edited by whodatschrome on Sun, 08 Mar 2020 06:00:16 +0000; edited 1 time

I didn't have a blind bearing puller, so I welded a nut to the bearing, then screwed in a bolt. When the bolt gets screwed in, it pulls the bearing out. It's a good idea to drop a flat washer down in there first so that the tip of the bolt doesn't gouge the case.

I also made some "dummy" bearing for both sides of the crankshaft. I sanded down both the ID and OD of the clutch side bearing and the OD of the fly side. The bearings now have a slip fit so it will make it easier to initially measure and set up the cylinder ports and squish heights.

Dude that is some nice work. Nice job on polishing the rod could have fooled me looks like it's supposed to. Nice job on decking the cases money well spent.

That is definitely some great work and no going back once you Mill out the case for web. Love that you hit a road block and just fix it with solutions that I would be terrified to try. Keep it up!

Thank you hibbert. Ideally I would to have loved to split the crank and polished the whole connecting rod, smoothed and polished the "window" in the web, and grind in an oil channel into the lower end of the con rod (the upper already has a small oil channel). I have a local guy who does all that work for a VERY reasonable rate, but he has a very bad shoulder right now, so I don't want to bother him. He also balances and welds up the crank pin too! He once built me an incredibly awesome T5 crank about 5 years ago. The engine was virtually vibration free.

Money is always going to be an issue for everyone, but if I'm paying for something that is high quality, then I don't mind. I figure more as an investment, rather than just "throwing money at it".

And I forgot to include an "after" picture of where the crank area was milled out so that the 53mm long stroke crank can now fit.

was wondering where that photo was looks beautiful

Nice!

And for kicks, this is when the case was still mounted up on the milling machine.

And in the meantime I "ringed" the stock exhaust so that I could take a peek inside. Pretty much all the fiberglass was gone. I might remove some of the baffles in it in order to get a little more power out of it. I'd be open to an aftermarket exhaust, but there isn't much (if any) exhausts available for a PK that will facilitate a spare tire under the cowl.

The DRT primary bascket that I bought is pretty dang ghetto. The actual grears look great, but the steel punched basket leaves much to be desired. The slots on the basket aren't parallel with each other, so only about half of the ears on the clutch plates will make contact at any point...yeah, that bad.

Rather than dealing with returning garbayparts back to SIP. I decided to order up a FABBRI primary basket. It doesn't come with any gears, so my plan is to take the primary gear off of the DRT basket, and install it on the FABBRI. And since I had already bought a FABBRI clutch a few weeks ago, they should play very nicely together.

Here's a pic of the DRT primary kit that you shouldn't ever buy!

Hmmm. DRT. Think it stands for Doesn't Run True.

When I fitted mine I noticed that the 'fingers' of the basket were different heights and scraped the cover. So with a fair bit of angst I got out the fine adjustment tool (DRT-AG4503).

are the tabs different heights or is the center just running out of true i.e. riveted crooked w/r/t the outer?

Did a lot of checking before deciding on that course of action. It all ran true and looked fine until I put the cover on. If it doesn't work out I'll replace it with something better... at the time I did it I had spent my last euro and that wasn't an option!

Ginch what is that fine little roadster behind you there??? looks mighty interesting

That was taken at Craig's last year, he can tell you more about it but it's a Triumph GT6 - but a convertible version rather than the normal hardtop. Since he's had the Vespas I don't believe very much work has been done on the Triumph at all!

My FABBRI primary basket showed up last Friday, but I haven't had a chance to really mess around with until last night. Here's a bunch of pics comparing it with the DRT version.

The billet FABBRI is very nicely made!

For kicks, I weighed the DRT basket. It was 13oz.