Jet size !!!

I have a DR177,Dellorto si 24 and sito plus exhaust.I have now a main jet 116.Is this the correct size?Or should I go lower?Thank you.

I have the timing at stock now at how many degrees did you set yours?thank you.

DR177, Si 24/24, Sito+, all porting

I have main jet 112 its OK (with 116 I have too much consumption [:drink:] )
Timing 17
But I have problem with idle jet.
I have 55/160 but i think its too big and engine too low go down from revolution.


118 should be ok, stock timing can coock a DR go at 17° and use a NGK9 or Denso 27 or Bosh 3 for spark grade.

It should be right. Depending on your weight you can try a 118 but I think it wouldn’t give you something more.


I have a similiar setup and use a 116 main jet too which works really well. I went out and bought a 115/116/118 & 120 and the 116 works the best for me.

You may also need to change your timing - which on my scooter made a huge difference to the performance.