Modern Vespa

Shaun, I would not expect the Malossi head to be compatible with the Polini cylinder due to variances in the actual fitting between the two makes, and the seal fittings etc. I'm judging that by what I can see from the photo's in this thread and from memory of when I fitted a Malossi kit to a customers bike. The head and cylinder MUST be totally compatible when doing an upgrade like this. They are perfectly matched at the factory and interfering with anything is a no no.

there is another cylinder kit to consider pairing with malossi head. the Taiwanese are serious about their scooter performance. the 335cc complete kits for xmax 300 are dyno proven double hp. 16whp stock to 33whp! it uses CM cylinder kit.

kit for vespa appears well designed. the cut on piston would relieve piston to valve contact worries. just my observation. I havent used kit.

CM 77mm 293cc PIAGGIO MP3 VESPA GTS 300 Aprilia SR 300 Max Big Bore Cylinder Kit

https://www.ebay.com/itm/CM-77mm-293cc-PIAGGIO-MP3-VESPA-GTS-300-Aprilia-SR-300-Max-Big-Bore-Cylinder-Kit/264731415491?hash=item3da338d3c3:g:ipAAAOSw01dZmvbF

Good find Jerry! Just need someone to try it out now. The GTS engines are very strong so could certainly take much more hp. Although I think I would draw the line at 30hp for the sake of long term reliability. But, you can actually get that from a Malossi kit if you do it right and use the right exhaust.

Setting off for a ride on Saturday, Sunny died on me.
(Sunny is my Vespa with the Polini 294 kit.)

I haven't done the full trouble shoot yet, but a sudden failure tells me it is electrical in nature.
I noticed that the controller that came with the kit is not showing power on the LED as it used to...

This GTS is the most tricked out I have read about...

https://scooterlab.uk/30bhp-vespa-gts-gone-mental-sunday-sluk/


For me, the 22 BHP of my standard 300 is fine and if I want to go faster I take my bike instead but horses for courses heh.

Must have cost a pretty penny or two to mod to that level. Props to the tuners.

Let us know how you get on with the tuning project if you do go that way.

Cheers.

Were you able to fix your controller? I'm dying to hear how well this works. Almost ready to flip the trigger on the Malossi Kit, but the Polini is a good deal, just wondering how it compares.

Hides his face behind his hand in severe embarrassment...

Vespa guru was not available to assist yesterday morning, so I towed the scoot to a private freelance Vespa tech nearby. He and I spent an hour thinking and checking connections and bridging out the Polini controller to go back to the Vespa one and zero luck - Sunny just will NOT start.

Just then, my Vespa guru rides up, doing a final road test on a 250 GTS he is selling to a colleague of mine. Tech and I complain about how we are battling to find the fault. He turns the key, hold the front brake and hits the starter...

NOTHING but the starter cranking it over.
He holds his hand over the end of the exhaust and repeats the action.
"Plenty of fuel, so it is electrical... did you check the spark plug lead...?"

Tech and I look at each other. Guru looks into the engine bay and peers down the right hand side between the engine and the body.
"There you are... the plug lead has fallen off!"

ROOT CAUSE ANALYSIS - PROBLEM DIAGNOSIS:
Instead of the correct plug with the crimped-on nipple, I had used a plug with a screw-on nipple. Same thing, right? Same thing NO! The nipple had vibrated loose and caused the plug cap to fall off. The loose nipple was stuck the inside the plug cap.
We removed the offending plug, screwed it into the nipple caught up in the plug cap and extracted it. Then we tugged out the plug with nipple and crimped it tight. Vespa guru hauled out a brand new correct plug from his bag of tricks and we fitted it, secured the plug lead on the engine and cranked it.

VOILA! SUNNY LIVES !

So, dear Vespa famiglia and friends, if your favourite scoot cuts out while you are riding, do check the spark plug lead FIRST!

Be safe.
Ride safe.

PS: The incorrect plug will be retained for roadside emergency repairs.

SIP has new video of the polini 294 kit. gives good visuals of the design and how it works. very nice design indeed. now on my wish list.

is there now any news on your DYNO test? power? speed?

Waiting aswel

I will see if I can get a dyno test arranged this week...

I found a crack in the rubber manifold between the throttle body and the cylinder head. That was the source of the idle surging that Sunny was experiencing lately. I swapped out with a donor scoot my Vespa guru has and she is now back to her normal purr.

hard to believe this mod has been out for 10 months and there are no numbers what to expect for gains. sad.

I think it is par for the course. How long have the Malossi Lambda Emulator and Malosi ForceMaster been on the market? Not a single bit of performance information about them either.

They chuck these things out to us and let us do the beta testing for them. No guarantee, no comeback. I have several expensive performance (?) mods sitting in a box in my shed. When my ForceMaster failed, I couldn't get any response out of Malossi. They just referred me to their user forum.