I have an SP550 I think it is and its called ultra easy start. In fairness it has usually been fairly easy. BUT this year it started 1st pull and each subsequent use has got harder to start. Untl the last few times its cut out randomly. (which I thought was a weird) but the last time I used it I found it really really hard to start. When it finally started it started smoking like a beagle. Carried in slowly getting better until it was clear after about 5 minutes. Does the collective think a reasonable assumption might be a sticking ring that frees up as it warms up?