PX 125,
Pinasco 177
24 si Dellorto with 120 main jet. 160 and BE3.

Kit is well broken in now with around 1000 miles on it. Was having problems with timing but have adjusted that and checked with strobe. Not exactly on 20 degrees as stated by Pinasco but pretty close to it. Performance is pretty good apart from what feels like misfiring when getting close to wide open throttle in 3rd and also in 4th. Could this still be because I need to adjust timing more or change jetting?

Also any recomendations on exhausts with this set up?

Cheers guys

I would try another coil.


Thanks for that. Tried a 122 a while ago but the scooter seemd to bog and not want to go over 40ish. Although I have adjusted timing since then. Will try 122 again and see how it goes now.


Hi Grant

I’m using the same Pinasco kit with a 26SI and a Sito Plus. I’m using a 125 main jet and after checking the plug many times seems about right. Engines can differ but maybe you’re a bit lean as your getting to full throttle. It would do no harm to try a bigger main jet, see how it goes and do a plug chop. I managed 65 today going up a slight incline revving out, must change the gearing some time!


have tried rejetting up to 130 and all were terrible. Best so far seems to be 160, BE3 and 118 stack…it got rid of that loss of power when wide open. Seen a recommendation at scooter centre for a 190 BE4 and 118 stack. Think I may give that a shot.
How do you like the 26mm? Do you think it’s worth going for it? Is it tricky to set up?



Hi Grant

I run a 190 be4 and 125 main. Did you try another coil as Curare suggested, he’s the man who knows!

I still get have a bit of a stutter when I go from say 25mph in top and open the throttle a bit to accelerate. After that it picks up smoothly.

Difficult for me to compare the 26SI with anything else as I went straight from the 125 barrel and 20mm carb to the setup I have now.

Not been on the forum for a while, snowed under with work and an ongoing Lambretta restoration at weekends.

Keep trying. AK


Still trying to find the right combination…will get there eventually. Bit of a pain constantly removing the carbox lid to change jets…does anyone leave it off when testing jet combos?

Haven’t tried a different coil as yet, as I don’t have one I could borrow to test. Will try a few more jets and then look at the coil. And yes, I know what you mean about Curare, he’s certainly the man…I like the way he encourages you to have a go at stuff.