Modern Vespa

Just got a malossi 177 kit iron cast put on my lml 150. How is the reliability of these kits? I took my bike to a great vintage Vespa shop who specializes in 2 strokes. They recommend that I get a malossi 177 kit vs the DR 177. I took their advice and it runs great!

Just can't shake the thought of this thing just randomly seizing on me while I'm riding. Anyone who has experience with kits and the reliability and what I should be doing to minimize my chances of seizing up. Is seizing that common?

It's reliable as long as the jetting is set up properly. I'm sure they set it up with correct jetting there as they know what they are doing, but it would help for you to pull the idle and main jet stack and let us know what your jetting is at. Also do you have air filter still on the carb and what exhaust?

Yep! Open up the carb box and tell us what exhaust and main jet installed. If you dont know what those are, let us know and we'll tell you how to check.

I put a cast iron Malossi 177 kit on my Stella last fall. I put maybe 600 miles on it before cold weather set in and so far so good.

I think the keys to avoiding a seize are two-fold. First, just take it easy for the first couple of hundred miles--no sustained wide open throttle. Second, make sure your jetting is not too lean.

I found this kit absolutely needs the rather rich 52/140 idle jet and BE4 mixer tube it comes with or it will run like crap at partial throttle. There is a little more room for variation with the air tube and the main jet, with one affecting the other. You probably will end up with an air tube between 120 and 160 and a main jet between 115 and 120--the bigger the air tube, the bigger the main jet.

If your kit was installed by a pro, I would be very interested to know what jetting they gave you.

I did a thread here on my experience:

Questions re. Malossi 177 cast iron kit for Stella.

It is full of deadends and misinformation, but you might find it interesting anyway.

What he said and on any modified motor I run at least a CHT

If anyone's interested on my jetting

Stella 2t sip road exhaust si 20/20
177 malossi iron cast

The 48/160 idle jet is lean for any setup and especially for the Malossi 177. The E3 mixer tube is a touch lean for this kit too. I'm surprised you are not getting any partial throttle bogging with this jetting.

The 140 air tube and the 122 main jet are ok, particularly if you keep the E3 mixer tube. Might turn out to be a little rich at WOT once you are broken in, but it is a reasonable place to start.

What exactly does throttle bogging feel like? Just regular bogging of the engine when you rev the throttle?

If so, no that doesn't happen

My process for getting main jet right following exhaust/kits change is the following.

You can see if you have a rich bog by opening up throttle to half open. Let the engine in 4th gear find its highest speed with the least amount of throttle. So on your setup (when its run in), your speedo will probably be indicating about 100 kmh 60mph. Then fully open the throttle. If it doesnt increase in speed or even decreases in speed with full throttle, you are too rich, hence the rich bog. You can then check your plug. Kill ignition, pull in clutch, wait for plug to cool, have a look at it. So if its black, wet, decrease your jet a size or two, then do the same process. When you hit the sweet spot, the engine will go to its top speed and will rev out; run out of gearing.

As to the safety of your kit, all kits are safe if installed correctly and you absolutely follow the instructions of running in for the correct amount of miles. If they say run it for 500 miles, as tedious as it is, run it in for 500 miles. Drive your scooter within the realms of what you feel in control of. I hit 65 on mine yesterday GPS (kitted DR177) and quite frankly i felt out of control, too fast for me. Better to be a little bit rich than lean for your safety.

Yo honestly how's the handling with your bikes. I literally spilled my bike 2x already maybe going like 25 mph on like stupid stuff like.. a little gravel and dirt. The first time it happened on a little wet street as I was making a left turn. Frankly I'm terrified of even driving this thing anymore. Mind you I have a Vespa lx 150 and a Genuine royal alloy 150. Never had a bad experience riding until I got the Stella.

Any words of advice? Obviously not the exact topic on this post but I know you guys have experience with these scooters

I think if your scooter is sliding on wet roads you need to ask on here as to what the best tyres are for you; a general all weather, all purpose tyre Some tyres dont have enough tread near the tyre wall and they can be skittish in the wet or if you like to lean into tighter corners the tread isnt making contact with the road. I run michelin S1's on mine, which are great in the dry, very grippy but a bit skittish in the wet. Other will suggest tubeless tyres, for safety, everybody has their own favourite tyre depending on their riding style or use. Some tyres are specifically aimed at the season too. As example, the tubeless conti tyres, great in the summer dry seasons, grippy for caning it around twists and turns but not great in the winter where the built up summer oil mixes with the leaves and wet, too slippy. From memory, in the UK, LMLS were shipped with really crappy tyres. Id start another post off for recommended tyres for you!

The PX is a skittish scooter in general. When i first got one nearly 40 years ago i had to drive back in a full blown gale across hills and it felt like i was driving something with a sail on it, easily buffeted across roads. Some have described the PX like driving a three wheeled shopping trolley whereby one of the wheels plays up. They are on the whole a very light scooter. Things like steering bearings needing replacement can make the PX meander on the road and be unpredicatable by simple things, like tram lines in the road (worn away by trucks), the scooter finds the long rutted section and starts to travel along it like a tram. Is a horrible experience, but decent tyres, correct pressures and new steering bearings sort these things out. It does un-nerve you for sure when you have been used to something like a royal alloy which has twin forks, larger wheels and a more central stable engine position.

That might be the best response I've ever heard. Thank you and yes everything you just described is the best way to explain how it feels. I did just upgrade to s1's. I guess I'm also not used to that front break. Seems like that comes into play with the spilling outs I've had.

Okay back to the tuning and jetting.

So yeah, I've definitely noticed an increase in power especially in 3rd gear. I haven't WOT in 4th. I want to break it in slowly before going wild with it.

Also I was told to add 2t oil straight into the gas tank for the first 500 miles. Mind you my auto mixer is working. So it's been running with more oil in the mix. Idk if that comes into play with the jetting being too lean

If it ain't broke, don't fix it. There is no way that 48/160 idle jet would work on my "Stellossi 177" but maybe your shop has some secret sauce we don't know about.

At the risk of jinxing myself, I've had no issues with handling. This is my first scooter, but I've ridden motorcycles for many years. I actually was surprised how familiar the handling felt despite the puny tires.

You kept the regular carb? Or did you end up throwing on the si 24/24?

So far, I've kept the 20/20 for several reasons. 1. Malossi does not recommend a larger carb for this kit. 2. The experts here said not to bother. 3. I've seen a report of some dyno testing that showed almost no difference in power potential between a 20/20 and a 24/24.

If your scoot is running smoothly as is, I wouldn't worry about any of this. Just abide by whatever your shop told you about breaking in and enjoy the ride.

Do you remember what the dyno reading was? Hp increased?

177 aluminum kit on their catalog says about 21-22 hp in pnp mode. Not sure how accurate that is. The 166 kit i have says 14 in pnp and 22 in fully tuned. I'm not fully set up jetting wise but I'm getting about 20hp using gsf dyno with 60mm crank and heavy porting and timing work.

Here is the article. Difference was insignificant. I see they were using a 24/24G, as was stock on T5s, and not a 24/24E, as was stock on P200s. Don't know if that makes a difference.

Actually that is the mhr 177 kit. Not sure if you have that one. I'd guess your 177 which i think was a replace of the 166 kit is probably similar power targets to the 166, so you are probably in the 14-16hp range pnp.

Edit: scooter center lists the power targets for the kit you have.. same as the 166. So you are probably at the bottom end or slightly higher in pnp mode.
https://www.scooter-center.com/en/cylinder-malossi-sport-cast-iron177cc-3-transfer-ports-57mm-stroke-single-exhaust-port-vespa-px125-px150-cosa125-cosa150-lml-star-125/150-stella-125/150-m3117676

The front disc on LMLs and Vespa are very effective, sharp and work, so if you slam them on when on gravel expect a very rude awakening. i was a fan of just using the front brake but having upgraded my rear brakes to SIP brake shoes its been a revelation as have always found piaggio PX rear brake shoes notoriously rubbish. So, my braking style has changed to using both together in even proportion and boy are they sharp and with new S1s fitted with deep tread i can control my stopping. We underlook our upgrades when adding power on with kits, consider the brakes to stop with that extra oomph. If you put in SIP rear brake shoes you will need to get used to them as you can do some rather dramatic skids if you are heavy on the brake pedal.

As to the 24mm carb, yes, id agree waste of money for a bolt on kit. I do have one fitted but I can get up to full power and top speed on my 177 without needing the full throttle i just run out of gearing. The 20mm would have done same job. I guess with an upgear the 24mm might help but for the extra MPH versus cost, is it actually worth it? 24mm carbs are relatively cheap but its still an extra cost for very little difference IMO. Im not going to upgear as i prefer the gearing ratio ive got for hacking around local and hill climbing.

On the Malossi cast iron 177 I ran both the 20/20 and 24/24. I felt that the 24/24 kept the bike from running out of air when really wrapping it out. I also gained some topend as well. However when I went to the 24/24 I also reduced my squish at the same time from 1.4mm to 1.1mm and opened up the carb box and intake to accommodate a 24/24. So take it for what you will. The transition from 20 to 24 jumped my main jet 12-15 points up in case you are looking for a ballpark to aim for.

Ended up changing my jetting to 160,BE3 and 122 main

Feels good, less sputter and pulls decent in 4th

1st, 2nd and 3rd pull great
Especially 2nd and 3rd gear when your in the high rpm range, you can really feel it pull hard.

What exactly controls 4th?
I'm assuming it's the jetting I just posted that really controls 4th but I could be wrong?

It is not so much a question of what gear you are in as it is a question of where you are on the throttle. Where are you feeling and hearing the sputter: 1/4 throttle, 1/2 throttle, wide open throttle?

That BE3 mixer tube is very lean for this kit. Malossi recommends a BE4, which is three steps more rich. I would not be surprised if you are getting some bogging at mid-throttle with the BE3.

The little bit of sputtering happens only in 1st gear half throttle. It starts good then you feel sputtering hesitation then revs high and goes away.

If you were to recommend a jetting what would you start with? Besides the be4

I have the same kit on the same scooter, plus a Polini box exhaust and a drilled air filter. After a lot of trial and error and learning on the job, I have settled on a 52/140 idle jet (as recommended by Malossi and supplied with the kit) and an AC160/BE4/MJ120 main stack (BE4 also as recommended by Malossi and supplied with the kit).

The scooter runs very well with that jetting. No bogging on acceleration and revs all the way out in all four gears. It does seem too rich at about 1/4 throttle, but I am beginning to understand that is normal when the jetting is right every place else.

Awesome I'll give it a go. I have a sip road exhaust. I wonder why the shop originally went with something completely different then what it recommend

I still have my Malossi 166 cast iron. At first I hated it a lot, I complained of the lack of torque but I had it now going 9 years and a few thousand miles and lots of full throttle pulls and this kit is super strong despite being cast iron. With that said I would imagine the new Malossi 177 cc being as good and more powerful and torquey.

As far is reliability, I fully trust Malossi. Scooterwest convinced me with Malossi and now all my 3 vespas run Malossi kits after a bunch of years and a few thousand miles on each one. good luck with your decision, my feedback on Malossi products is positive.

As far is seizing, I had half a dozen seizes on my P200E with the stock engine and with a Pinasco 210, the moment I started using Motul 710 full synthetic I haven't had soft seizes anymore.