Need to upgrade from Sito to Simonini...Main Jet?

Hi All,

I fitted a 26mm carb to my 125 using a 120 main jet…I am now looking to upgrade my exhaust from Sito to Simonini, can someone suggest what main jet to use.

Thanks and regards,



I confirm what sliphorn said. If Sito plus one jet bigger would do it.

Is your Sito a standard one or the +? If it’s a Sito+ then I’d start with a 125 with the Simonini just to be safe. The Simonini as compared to the Sito+ shouldn’t need that much of an increase in jet size.

Thanks Guys,

I will change to 125 main jet.