I have two O.S. Motor and these engine are reliable and last quite long (if tune right). My .12 CZ-Z (9 years old) motor have about 11 gallons of fuel through and still have good compression. My TR Turbo have 1 gallon of fuel and it’s pretty fast, it not as fast as the Nova Rossi based motors but more reliable. Just make sure that you always see a steady stream of smoke on the straight and do the five second idle to adjust the bottom end as stated in the manual (page 15).