Well guys, a little 'year later' update for you. The troy-bilt 4-stroke trimmer is no longer. I should have asked before I bought it last year! I took it back to Lowes and exchanged it for another make/model. Each time I used the Troy-Bilt trimmer, the more I disliked it. I hated the 'quick change' string head, where you force feed a pre-cut pc of line in there, I hated the direct-drive (no centrifugal clutch) 'feature', the weight and vibration were a bear and the unit was a pita to start. I think most of the starting difficulty was my doing though. If the unit was not stored properly, engine oil would seep from the sump into the combustion chamber, soak the sparkplug and load the muffler. This lead to hard starting and a HUGE blue cloud. It also had this weird zip start clock spring type of recoil start. I go so fed up, I tossed it back in the box (had it up in my garage loft), grabbed the receipt and went back to Lowes. I thought they would give me more of a hassle since their OPE return policy is 30 days. Almost 13mo later and they didn't even bat an eye! The woman commented she was surprised I still had the receipt. They were so good about it, I figured I buy another trimmer from them. I went with a Husqvarna 125L. I used it for about 30min today. Very nice. Smooth, powerful, real snappy throttle response and LIGHT! I love the clutch and ease of starting. I didn't notice any smoke or smelly exhaust from it either @ 50:1. From reading the literature, I discovered it has a catalytic converter buit into the muffler. No idea these were on 2-strokes. The Husqvarna was $199 as opposed to the ~$150 troy-bilt. No more 4-stroke trimmers for me unless it's a Honda or better. Live and learn!
Joel
