dear i write that reply 2 times but PW hangs so it wont displayed,,,,,,,,,,,well you can use 200 cc 4 stroke riksha exhaust,,,,,,,,,,chose the one which is factory fitted on 200cc engine , may be there are some riksha which have bigger engines so buy the exhaust of 200 cc engine only ,,,,,,,,,,,another thing,,,,,,,,,,,i guess that 50% noice is mechnical and comming from crank case , so you have to address that issue as well ,,,,,,,,,,,,these engine comes with metal camshaft which creates lot of noice,,,,,,,,,,,,you have to replace that camshaft with teflon ,,,,,,,,,,its easily availabe in market,,,,,,,,,,,i am sure you will get some batter result if both these mods executed properly,,,,,,,,,,
