The manifold is spot on? The inlet to the motor end of the manifold is much smaller than the inlet from the carb end of the manifold. Its spot on thats how all kits come. It aint no china head on these 50s its the size for the stock head. Unless you where a mad nob and decided to get a maniold with a larger inlet it wouldnt do **** as the intake is still only tiny.
Dont bother about buying another manifold. Two bro's are tried and tested. My kitaco is the same.
Flarry the xr50 and the crf50 motor is exactly the same , the crf50 superseeded the xr50 , all that was changed was the plastics , seat cover and the kickstart. The kit will work with any honda 50cc horizontal motor 1991 and upwards.
$100 for a cylinder and a carb is still a bargin. cant even get a decent 20mm carb for $100 nowdays. So for a complete bore kit like that is sweet.
My rear brake pedal costed more than that bore kit , which is an indication of how friggin cheap that bore was.