Px125 disc > Pinasco 177 ? gearing?

Hello, I have standart px 125 disc (2005),
I want to do a soft tuning for touring (each day ~50km highway + long trips >> I need higher cruising speed ~90-100km/h)

I’m  planing  install a Pinasco 177 cc Kit,  Carb Si 24/24 and Sito Plus exhaust. is tid a good choise?

what about gearing? do I need clutch with 22 cogs?
like this: cosa clutch with 22 cogs

Art.-No.: 93032000

(I think standart px125 disc has the same, but with 20 cogs)

do I need to split engine for installing new clutch?

and one more question, do I need something more for finish/setup (except main jets nr. 114, 116, 118, 120, 122)?
Thank you

Hi i have fitted pinasco 177 for 7 months now.I fitted 24mm si (i think of p2 auto lube)and jetted to 118 main ,190 main air corrector jet and be4mixing tube.The exhaust is simonini…I havent changed gearing or clutch and havent matched the casings to the cylinder.I get max speed of 115-120 kmh(70mph) cruises nicely at 100-105(60-65mph)The problem i get is at 60-70kmh where it sort of missfire intermitantly its ok if i either let off throttle then re-apply or accelerate faster.also when say cornering speeds(slow at junctions)the very 1st part of throttle creates what feels like overfuelling and goes if you accelarate hard. Im interested in knowing more about modification to the baseplate between casing and carb If anybody can help?As for gearing and clutch as standard everything seems ok(done approximatly 3000kms so far)Basicly its great kit if ridden hard lots of tourque compared to standard .Interested in what a pinnasco exhaust would do .Only problem i have is where i am in uk nobody stocks pinasco parts bought kit from Germany.Hope somebody can help Thank You .Andy Clarke.

The throat of the "Gs" are shorter then the E's , it gives more room for a taller air filter.  Gs are more difficult to jet.

If you are to get a "G" get the 26/26.

Get more on tunning, jetting & carbs at www.stellaspeed.com 


Hello there.

I have the same setup you are planing to go by.

Don't do the P200 23/65. Won't pull right a on a windy road.

I had to switch to 22/65 (but my bike is all ported w/ cutback crank etc.etc.)

Stock, you have a 20/68 there.  If you can mount the new 22 cosa clutch there is the best.  I measured the 22 cluch and the teeth area diameter is the same as the 20 that you have. So, I don't think that you have to open the cases to change the primary gear to the 67.

As it comes, your gearing ratio is 5.81/1 (5.81 turns of the engine for each turn of the weel) = 99 kmph @ 7000 rpm.

with a 22/68 you will get 5.29/1= 108 kmph @ 7000 rpm

 and with a 22/67 is 5.21/1= 110kmph @ 7000 rpm

I stongly suggest you not to go beyond 22/68.

Don't need to open cases at this time, but take away the base of the carburator case to match the hole with your new carb. (use a drill, a high-speed rotary tool, or a file.)

If you don't want to do this, the stick to your 20/20 carb cause you wont benefit of the bigger carb (expect it to work worst and give you headaches on jetting) .

Check on www.stellaspeed.com for help with jetting.

You need to know before you embark in the project, that the most diffcult part is gona be to properly adjust the jettigs to the new kit and exhaust. 


Regards, Juan


Thanks for help,
by the way, is there a big difference between
Carburetor SI24 / 24E DELL’ORTO with oil pump
Carburetor SI24 / 24G DELL’ORTO from T5, with oil pump ?

24E at this moment is not available, and I don’t know when SIP will have it,
so maybe I can use 24G?