RGV 250 and Aprilia RS250 Cross Compatability

[pkay]

Hi Guys
My 99 RS250 will not fire on the top cylinder for some reason. I have gone through air and fuel and think it is spark related. In anticipation of the worst does anyone know whether the black box off a similar vintage RGV 250 will fit the RS250 or is the programming different?
Many thanks
PK

[2TInstitute]

Interchange no problem. Have you tried earthing the coils back to the negative side of the battery from the
mounting bolt

[pkay]

Thanks for the suggestion. I did all the contacts and cleaned up a heap of grime. In the end I had a clogged jet (duh!!) but it also now starts on the button so I think of benefit alround.