Reed Valve conversion

I have just tried to fire up my v90 series 1 and found that petrol is coming back through the carb. I think this means I have a damaged pre com and need to go for a reed valve conversion.(I did notice some small scratches during the rebuild but thought it would be OK) I currently have a 19mm delorto. Does anyone know if the polini Art.Nr. 21502030 comes with all I need or will I need to get reeds seperately.

P.S. if you want to tune a smallframe stay away from the pre 65 unless you want headaches.

Hi dude,


Possible that the rotary valve is too bad, hard to say because i got no picture.

The 21502030 includes the manifold and the membrane block and plates.






PS: I agree with the pre 1965 problem, the first series engine is complete different.

      Never touch a first series engine, sell it or keep it and take a 2. series to tune it.