my higher performance Rossi, an YS 2 strokes are pretty sensitive (especially Rossi), but really perform when compared to the main stream brands... i have a harder time getting them to start, but once they do, they really run well, seldom dead stick.... on the other hand i have my classic OS FSRs, they start really easy , are easy to tune and rarely deadstick...welll maybe once or twice, and are reliable but not powerhouses