1976 50cc special

 hi i have a 1976 v50  to which i have added a racing crank and a polini 115cc barrell etc and a 19/19 carb ---it starts first kick every time on choke -- warms up and idles but will not rev up from idle --any ideas folks before i rip it apart again !! cheers[:'(]

well being new to the game not sure which jets are what but the three jet sizes are as follows-42 -60-72

any help would be much appreciated

cheers ken

hi ....


i recommend you 2 pipes


1. the sito et3 banana for more tourqe (2419000) wich fits on your non PV/ET3 engine ... (different joint pipe)

2. the polini pipe for more refs (20020300)


you can also think about a primary gear 2.86 22/63 teth (15310000)



hi dude ...


what jets are in your carb ??


mainjet etc ...


wich spark ?

hi plug is a B8HS (ngk)

have also tried a Champion L86C

pass as too what jets are in the carb ut will strip again and find out

i have however tried a 16mm carb off a 50 special that come with it and it does the same

have rigged a plastic fuel tank up about a foot higher up with no filters !!! was going to see what happend today but it has snowed and the children whanted to play

will get jet info monday night

cheers ken

all sorted must of been a duff oil seal !

stripped found no fault and rebiult with new seals all ok

hy dude


this sounds a little bit strange to me ..


do you changed your piston ??

is it possible that the piston was mounted 180 degrees reverse ???

fitted the piston with arrow pionting to rear (i think if i remeber correctly )

whilst i am about it when i get it running correctly  what exhaust would you recomend

cheers ken