Solex forum Forums Solex techniek Solex Tuning CFX improvements

I have bought a 39.5mm CFX cylinder (IMPROVED 2022 version) with piston and Race cylinder head, are there any improvements that should be made with piston or ports with dremel before I mounting it ?

My solex has a bored up 8mm carburettor, larger intake pipe and 18mm exhaust pipe.

It will be used for everyday driving.






Ik heb een 39,5 mm CFX-cilinder (VERBETERDE 2022-versie) met zuiger en Race-cilinderkop gekocht. Zijn er verbeteringen die moeten worden aangebracht aan de zuiger of poorten met dremel voordat ik deze monteer?

Mijn solex heeft een verveelde carburateur van 8 mm, een grotere inlaatpijp en een uitlaatpijp van 18 mm.

Hij zal gebruikt worden voor dagelijks rijden.


https://solexdeal.com/solex-onderdelen-online/solex-race-cilinder-set/
https://solexdeal.com/solex-onderdelen-online/solex-race-cilinder-kop-decompressie/

It was this piston modification that I was thinking of.
Would that bring anything positive ?



Het was deze zuigermodificatie waar ik aan dacht.
Zou dat iets positiefs opleveren?

it is a start, you have to ( locally) shorten the piston, 1/2 way the inlet to make the left hand side of the inlet open first ( and close later) if the piston is still original in length remove about 2 mm ( in height) over a length of aprox 16 mm ( staring the measurement at the side of the slit in the piston, the ones you have made your own improvements on

Thanks Joan.

The piston I wonder if there is any profit to modify is the one that came with the purchase of the CFX cylinder.

The image of the piston in the post above is just an example image from the internet of a piston that someone else modified.

My piston has a total length of 49.97mm from top to bottom.
From top edge to bottom edge it is 47.02mm

So if I understand you correctly, you can/should shorten the piston approx. 2mm with a width of approx 16mm i the piston is the older long model ?

If the piston is the newer short model then shorten it only half the width (8mm) of the intakes left side ?

the piston that comes with the CFX needs minor modifications as indicated, pistons are the same for the older CFX compared to the new CFX nowadays one may have to say the " intermediate" version I was told that a new manufactur was invited to produce them I do not know whther there will be additional modifications ( improvements again can/should be made)

Thanks Johan.

I tray it as is it before i do something else.