There are many factors behind the lifespan of a two stroke engine. Oil ratio being one of them, more is absolutely better, with a few qualifications. It must be a quality oil, jetting and timing must be correct and quality fuel of sufficient octane must be used. Even mild detonation can greatly shorten the life of a two stroke.
The other aspect of a two stroke engine is component and build quality. The Poulan leaf blower uses a consumer grade engine, even with the use of plenty of oil, good fuel and proper jetting, it's lifespan won't match that of a professional grade engine. My 20 year old Echo is still running perfectly, even with a great many hours of abuse.
Last edited by Cujet; 05/13/20 05:32 PM.