hey i have a gs-15 with the single needle carburetor and the standrad pipe in the tr-15. ive worn it out due to me not knowing how to tune and perform maintence and several stupid moments such as when the air cleaner came off. my question is:
if i were to replace the piston and sleeve, conrod, cylinder head and buy the 2 needle carb would it be as powerful as a os 12cv??
and is it easier to tune than the os?? thanks all

Yes and Yes, probably even more power!

ok ive got my gs-15r aparat and i removed the bearings now the front bearing has dual shields (one on each side of the ball race) and ive been thinking should i remove one shield as to let oil and lubricants in?? id remove th inned facing side so ast to still have a shield on the outer(flywheel) side so as to keep crank case preasure and oil in the motor opinion??? is this a good idea or not??? thanks all