sr50 70cc big bore problem

Piaggio sr50
Tehno gas exhaust not sure what model

Piaggio NRG 50 Power DT AC 07-09 17.5mm Carburettor with Auto Choke
70cc cast iron cylinder kit from Naraku for Piaggio

Aprilia SR50 R 45° 28/35mm Racing Air Filter Red

ticks over ok but when reved bogging down
tried a 76 main jet bogging down
82 bogging down
92 bogging down
98 bogging down
102 wont run on this jet
any idea just wont run on this filter

 

You need to restrict the filter a bit somehow.
This is why I tell people to use an airbox

 

Do u have the factory manifold ? Also 17,5mm doesnt work on open filter good.

 

yes was running better with air box but getting hot do I leave the brass washer in back of carb the one with holes in

 

Thanks for reply yes original manifold going to try a 80 jet and change crank seals and try orginal filter like you say as seems to be getting hot

 

Open filter doesnt work on 17,5, if u want to use it get 19mm or 21mm phbg carb. Also remove the restrictor plate with the holes , and modify the airbox inlet diameter to 18mm and then jet it should be 65-85 somewhere.

 

im going to leave 17.5mm carb on so do you mean to leave brass washer out with holes in it and make inlet hole in air box bigger to 18mm

 

WASHER OUT, and the intake tube that the AIRBOX takes air from in stock is 12mm i think make it 18mm inside diameter.