Torquing up a TFR?

I'm really a little heavy for my TFR, but there's no budget for something stronger, so I'm wondering what I can do to bump up its low end torque a bit.

I've already installed cosmo's larger rear pulley. The design of the sheet metal won't allow anything larger yet.

I'm willing to trade off top end speed and/or mileage if I can get this thing a little more perky from a standing start, esp as much of my usage is stop and go.

Can anyone suggest jet or carb changes, replacement exhausts or other (hopefully not too expensive) options? Everyone says "Vespa stuff will usually fit", but no Vespa dealer seems to have ever seen (or admit they've seen) a TFR, to know what will and won't fit one.


Re: Torquing up a TFR?

Kinetic TFRs are almost exactly the same as the Vespa Ciao. You can get a 70cc cylinder kit for them from Fabio at Vespa Super Shop for $175, or you could order one from for less. They will help your low end torque even if you don't have a bigger carb (though you will want to rejet).

A cheap mod you could do (though I don't know how much it will help the low end) is to drill a few holes in your airbox and put a (correctly sized) larger jet in your carb. Jets are like $3 apiece, and holes cost nothing.

Re: Torquing up a TFR?

Opening up the airbox would be easy, do you think air intake is a limiting factor right now on a stock TFR?

A replacement jet would be easy.

I really wonder if the teensy little exhaust pipe isn't a major limitation on the total power. Do you know anything about options in that area?

Re: Torquing up a TFR?

I think it always is. I know it's been done to Vespa Grandes, so I know the Ciao / Kinetic would be at least the same if not more restricted. Unfortunately with the Vespas you will be unable to get a larger carb on it...stock is 12mm and the biggest you can put on the intake is 13mm. The intake is a part of the engine case, so any bigger isn't possible without some serious modification.

The exhausts are restrictive, for sure. But a performance pipe will actually hurt your low end a little bit. Or so I've heard.

Re: Torquing up a TFR?

Charlie Bond /

they hurt the low end ALOT! i have one for my grande and the low end sucks! top end though is pretty nice, just getting there, like i said before, sucks.

Re: Torquing up a TFR?

"They" being unrestricted or less restrictive exhaust?

Hm, okay. Do you know of anything anyone has done to the intake end to improve low end, then?

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