Long stroke crank wih Pinasco 177

Hi all

I finally opted to buy a Pinasco 177 kit to go on my LML 125. Also bought a 26mm SI with a range of main jets and already have a Sito Plus on the bike. Thanks to contributors such as Curare, Adrian Newnham, Vespadoc and others for adding to my knowledge of Vespa (LML) tuning and helping me to decide to buy this kit. This forum is invaluable. I’ve only ever worked on Lambrettas but use the LML for going to work (it was cheap) and I’m very pleased with it.

The LML is quite new so I don’t want to take the engine apart to fit a long stroke crank (just yet). Too busy with my old Lambretta for now. I’m hoping the Pinasco kit and carb will just bolt on and work, more or less. Setting up the carb I can handle. I noticed that SIP advise fitting a long stroke crank with the Pinasco 200 kit but do not say the same for the 177 kit in the advertisement on the site. Although, other forum contributors advise that one is fitted with the 177 kit.

Any advice would be much appreciated.


Thanks Curare, Adrian

Think I’ll leave the ports alone for now as I’ve no experience of riding a bike with one of these kits and wouldn’t mind experiencing it in standard form first. Will start with the Sito but may invest in a PM pipe later. I’ll manage the opening up of the carb mounting block OK. I did a similar thing with my Lambretta when fitting a 25mm carb manifold to the alloy barrel using a flexi drive on a dremel. Bought some excellent polishing stuff on line from Perfect Polishing can get you the phone no. if you’re interested. Used abrasive paste and then polish and the lammy ports came up mirror-like in no time. May start with a main jet bigger than 125 now just to be safe and then work down, Adrian. Just got an email from SIP this morning to say it’s all been shipped so may do the job at the weekend and let you know how it’s going. I’ll inspect the crank too, Adrian, and probably get a stronger one later. Only a few hundred miles on the clock now so hopefully a bit of life left in it!

Keep up the good work, cheers. AK

Hi Fellas

Adrian, sounds like the carb box and gasket were a major restriction to fuel flow on your bike. If mine achieves more than 10 bhp I’ll be quite pleased. Big improvement on the present tiddly 6 and a bit. Curare, I’ve never worked on this type of engine before but wouldn’t lengthening the inlet port require an engine strip to avoid debris falling into the crankcasing? I’ll check the instructions when the kit arrives. You mention the gearing Curare and mine will be a bit low for the kit but I’ll leave it until I strip the engine later. I’d imagine the gearing on mine is lower than yours, Adrian as your top speed seems very good. May seek out a place with a dyno when I’ve got time. Trying to get my Lambretta bodywork finished and it all assembled, getting it blasted over the next few days and want to spray it myself. Could get someone else to do it but that’s no fun. Got all the kit now and read a few books, will practice with the primer before applying the top coats. Had my last motorbike in the early eighties but have gone a bit mad this past year. Don’t know what’s come over me.

… yes you could damnage the nicasil.
Leave the Pinasco 177 the way it is, make inlet port longer, and if you have money by a PM exhaust that goes well with the caracter of pinasco. It has Sito plus power range curve but more power no doubt, in the easy to get rpm range.

Oh yeah, it will be best to change the crank at a later date, and the engine bearings, The Indian quality of these parts are not as good as Italian stuff. I plan to fit a Mazzuchelli crank and new bearings in due course. Don’t worry you will get some years of use from the standard parts but they will need to be replaced if you want extreme tuning. Look at the crank when you swap the carb over, mine looks like the webs have been cut with an angle grinder, and Indian bearings are not known for their precision tolerances. They will be fine for a few years of every day use but when they need replacing use better quality kit. Vespadoctor told me it would make a big difference just stripping the engine, polishing and balancing the crank, and fitting new (good) bearings. But reworking the crank will cost as much, or more, than a superior Mazzuchelli crank off the shelf, ready to go.

Hi, the filter foam is available from most bike shops. Not sure on re setting a vespa oil pump, on yamaha lc’s etc you can adjust a cam inside to let more oil in, or adjust the cable, if you can’t alter a vespa pump just put a little oil in the fuel and get the best of both worlds. My LML is more thirsty but I am still getting 100km/ 60miles to a gallon, that may be cos I have been running in and not thrashing but I’d be happy with 30miles a gallon.

Good news mate, wasn’t sure on the oil pump, never had an autolube vespa, have had Yamaha lc’s, the mechanical vespa pump sounds better than the cable lc one.

Oh and yes I matched the airbox and the carb like you said. Mainly took material off the airbox on the carb side and then cut the gaskets to suit.

No mention of ignition timing with the kit. It just detailed changes (lengthening) of the inlet port. I didn’t do this as it requires a major engine strip. Will probably have a go at it later when bearings etc need replacing.

Thanks, it will have to be ok as a bolt on, at least for a while but everything will be done eventually. Cheers. AK

Hi AK i’m in Blandford, Dorset. Cutting the blue part off the filter may work but the white is the finest, most restrictive part, I am looking at doing the same to try it, but cutting off all the gauze and using filter foam, I got an 18inch square of 3/4 inch thick filter foam so I will cut a single piece to fit the alloy filter frame. Is your scooter premix or autolube cos premix have bigger main jets to allow for the oil mixed in the fuel, autolube can use smaller jets cos it is just pumping neat fuel, you will need to jet to suit. If you have autolube you may need to up the oil feed to allow for the extra fuel the 26mm carb will flow. I prefer premix as you know what oil mix is in the tank all the time. I read in Norrie Kerr’s Vespa Tuning Manual that a 28mm carb flows 95% more fuel than a stock 20mm carb, so a 26mm carb should be 75-85% more efficient, it makes your bike juicier but worth it.

Hi all

Pinasco 177 Kit arrived on Friday so put in on Saturday. Increase in power seems quite substantial. could do with a fifth gear but a gearing change can come later when a strip down is required.

The torque it gives is extremely useful, pulls like a train, far better than forever going up and down the gears as before. Started with a 125 main jet in the 26/26 SI carb, maybe a bit rich but I’ll keep checking the plug. It seemed OK after a half hour ride, chocolate brown around the electrode, bit black away from the electrode at the base of the thread. Using the Sito Plus, it seems noisier than ever. Don’t know if anyone can suggest a quieter pipe?


Hi AK i used a flexi shaft in my bench drill with different carbide burrs, and finished it with fine wet & dry. You don’t need to mirror polish it just smooth it, some people don’t smooth them much at all, they feel if you leave it a bit rough it causes the fuel to swirl about mixing better. It’s up to you. My LML has only got 1800kms on the clock so I intend to get some miles from it before I do the crank and bearings myself. Look for my posts to see the set-up i have on mine, she is running 10.1bhp at the rear wheel at 68.7mph just by improving the carb, pipe and setting it up right, That was at 1500km so not quite run in, I asked him to be gentle, she should be better now.


I have „cocked“ this kit in all its possible form, normal stroke, longstroke (1,5mm base gasket, or with head gasket after modification of the head and of the top end of the barrel since you have to make flat the recessed part of it that accept the pinasco head if not you can’t fit the head gasket) malossi reed intake, and also tried the barrel with worked ports.

After all this this is what I can say:

The option of longstroke with head gasket is good only if you rise the exhaust port. Unless you want a tractor.

The option with longstroke and base gasket is a good option if you want a more sportish power range, it is reliable, but I will advice this option only with the use of reed intake. If not you will have hard time in finding a good set up for carb.

But at the end I think it doesn’t make sense make this cylinder more sportish. It will be always less powerfull then Polini or Malossi, and for the mod you will spend a lot of money (longstroke, reed intake). In this case if you are curious just buy a polini cylinder to try insted of the pinasco. It will be fairly cheap and you can always go back to the pinasco.

I will stay with the standard pinasco with maybe the exhaust port just a 1mm higher (if you really want a little more power at higher)
Gear 21/65
your choice of carb is perfect
Work a little the inlet port to have a longer inlet time.
And if you really want put a mazzucchelli race crank, but I would just work the inlet port to avoid the more vibration you have with the use of a race crank. I would privilege confort in an engine like this.
And if you want something more you could modify the top of the barrell make flat the recessed part of it, so you have a flat plane, and fit a polini 177 head, and retard timing 1 degree. But it will cost some money for not too much.

Thanks Curare, this forum is brilliant. I’ll just bolt the kit on when it arrives. was thinking of starting with a 125 main jet and then working down. I don’t really want a revvy Mallossi type engine and wanted to keep the autolube.

I chose the Pinasco after reading other postings that mentioned the even spread of power. Reasonable fuel economy would also be nice as it’s my daily transport. I don’t want to be stopping at the petrol station twice a day! I may have a go at the exhaust port later after I’ve used it for a while but I worry about damaging the nicasil plating. I’ll fit the kit and let you know how I get on by posting here.

Thanks, again. Anthony

Hi A-K you should be ok with the 125 main jet, I run a 120 in the 26mm carb on my stock LML 150 motor, I have not altered any ports on the engine or barrel, I did match the carb, gaskets and airbox together when i fitted it, I cut a new gasket to fit the engine inlet (the original half covered it) I marked the gasket to the bottom of the carb box. Then I made a new gasket to suit the hole in the carb and marked that to the top of the carb box. You will see the carb has a round hole that sits slightly to one side of the oval hole in the airbox, and the oval hole of the carb box sits slightly off of the engine inlet hole. I increased the oval hole in the air box to match the oval hole of the engine inlet, and then blended the round hole for the carb into the oval and smoothed it all to improve fuel flow. (It’s hard to describe matching a round hole to an oval one but you will see what I mean, basically match the oval hole in the airbox to the oval engine inlet, then you will see 3 parts of the round hole for the carb will be marked in the airbox, angle these bits into the bottom oval edge to funnel the carb into the engine inlet, finally smooth all the edges to take off sharp edges and flow together). You will be able to alter the engine inlet at a later date if you want to go for more extreme tuning. I hope this helps.

Hi, I’ll just have to see what they send me. Mine’s autolube and came with the 92 main jet also. Using filter foam seems like a good idea. Where did you buy it? Take your point about using premix and don’t quite understand how the oil pump regulates the quantity of oil relative to the amount of fuel but I like the convenience of autolube. I’ll have to mug up, I have a Haynes manual but they’re very basic and cautious in their explanations. Norrie Kerr’s book sounds good. I have an excellent manual for the Lambretta that was only slightly more expensive than the Haynes, no comparison. Looks like I’ll be at the petrol station more often but the extra poke should make it worth it, especially on hills. I’ve only had the scooter a few weeks but it’s made going to work around London so much quicker and much less boring than driving the car and standing in bloody school run traffic.

Thanks, Curare, I want to keep using the autolube, one less thing to think about. I recall some previous postings on giving timing sdvice for different setups. Was hoping some instructions suggesting settings will come with the kit. Or, if they don’t I can always find out from this board!

Ade, came to work this morning without the blue gauze on the filter and there’s definitely an improvement. Checked the plug and still chocolate brown so OK.

Hi Ade. Take your point about the noise, neighbours will just have to put up with it. Luckily a Piaggio filter came with the kit. Not sure of what to do with the timing and didn’t check it. What do you reckon I’d need to do? Just check the accuracy of the factory setup with a strobe?

Thanks, I’ll check, could teach myself to use a strobe. I’ll check in the manual and mug up before I do anything though.