Vespa t5 172 mallossi

[lloydiee]

I've built a mallossi nothing crazy as its for the missies to get her used to the road but I've ridden it a few times and it's gutless as arse holes dull as dish water the max I could read on the sip speedo was 65mph and no more

Right here it is

Mallossi barrel 172cc

With a billet head recommend I had a the head pinking with a 1.2mm squish so I raised the squish up even more seems to have stopped

Standard crank

Jl4 snail exhaust

21 tooth clutch

Fuel pump in the back of the casings as its used a longer fuel tank as the tap is lower its running a standard carb

What have people done to the exhausts ports on these mallossi kits the seem tiny

[ducksta]

Something wrong mate that should be good for 70+

[sean brady scooters]

lol,...even malossi reccomend you alter the crank to get the benefit from it

[paul d]

I agree with ducksta. I've no experience with the snail exhaust but maybe a 20 tooth clutch would help it reach the powerband of that pipe? On a standard carb 120 main with the standard exhaust, 122 with sito plus, 125 or more with scorpion which might be similar to the snail exhaust. I haven't modified the crank on mine because it's quick enough for me as it is.

[lloydiee]

That's one thing i didn't do was cut the crank back to increase the inlet duration.
But I flowed the cases opened it up smoothed the inlet but didn't go of the rotatory pad

I had a look on a vespagerman.de forum and found some useful information they where widening the exhaust port to 48mm from standard is 44mm

Raised the exhaust to 190 duration

[paul d]

Impressive work! I'm curious to see how the exhaust port affects your performance. I've never touched mine or the inlet because even out of the box it didn't have the widest power or torque band to begin with and it reved high enough for my nerves! Jeez nicasil is difficult to port. I tried to remove a ledge of it that was left in the exhaust port from the factory but it broke off as I was filing it and I was going very easy with a good file. That kit ran fine and the patch of missing nicasil that broke off never got bigger. 22 clutch and standard pipe is where I've ended up. Doesn't rev as high as with expansion but satisfying over distance and can push up hills and into headwinds no bother. Best of luck with it!