Polini 177 on px80

does anyone here know if a polini 177 made for a 125 fits on a px80. It will probably need some modification I was wondering which ones and do I need another crank shaft to?

Orginal crank PX80

  • DR 177 or 135
  • Malossi 166 or 139

My sugesstion:
Orginal crank Px80

  • Malossi 166,
  • Upgrade gear 23:64,
  • carb si 24/24
  • Exhaust leoVinic

If you change only crank (PX 125 - 250) you have more configuration, but speed no more increase [:(]
You must upgrade gear (kit malossi or polinni 23:64) or change gear cluster from px 125 (suggestion 150 or 200)

I don’t know the 80 engine but I believe it uses a shorter stroke crank as the Malossi 166 and DR 177 can be used in a modified form.

Using this basis I’d presume that the spigot is the same size and therefore a 125 crank can be used.This is purely a guess as I’ve no idea if the casings are from the same cast at all.

Perhap’s you’d get a more definate answer on GSF .Sorry I can’t help more.


yes you need to change the crank with a PX 125 one. Then you can go without any other mod, as far as I remember. I have seen only one PX80 in all my life…