Changing the Carburettor on PX 200E 24mm or 26mm

I have a warped carburettor body on my dellorto SI2424E . Im going to replace it.  I'm also changing my exhaust to a SIP road 2.0.

I have read that you need to use at least a 118 min jet.  However I'm wondering if I should also change up to a 26mm carb. The rationale being that the bigger carb will help keep the engine  cooler with the new exhaust.

I would prefer to stay with the 24 mm carb, as the 26 m is much more cost . So my quesiton is this. Is the 24 mm carb  with the 118 main jet going to be OK or is really worth going to the bigger size 26mm.

My main focus is making sure the negine is running cool as possible,  im in Jakarta Indonesia, the temperature is never less then 29 degrees C, and the chances to open up the thorttle and go fast are very limited any way so speed performance is not a key issue.

Thoughts and comments appreciated.

Air doesnt cool your engine on the inside ,fuel does.

So placing a bigger carburator isnt always the best solution.

If you are driving an standaard cilinder and you are going to a sip 2.0 i would start with a 125 jet maybe even a 128 and then work yoyr way down to get it right.

Remember more fuel is a cooler engine to less fuel burns your engine with a hole in your piston or a sticking piston as result.


Good luck,

Thijs Noort.

the Netherlands.




Hello All

My PX150E has carburettor 20/20D with the oil pump. This is the first time I order from SIP some PX spare part with the new carburettor w/o oil pump. The guy at the vespa workshop check the new carburettor and replace the old one with oil pump. My concern is do I have any trouble if I still keep the new carburettor w/o oil pump with current system?

Thanks and Regards