I have dismantled a number of Homelite trimmers that have failed. The most common point of failure is the lower rod bearing. When this goes, it usually takes out the piston and cylinder. One of the boat manufacturers offers a superior rod bearing, it would probably behove one to replace the bearing when converting a Homelite. They also offer welded crankshafts. There are better engines for conversion. The newer engines, from MTD, seem to be much better construction.

Ralph;
The Ryobi SS30 I got from the same source had a starting problem that was caused by loose cylinder bolts. So far the plating has held up. My suppliers inform me that no parts will be stocked for any MTD 2 cycle machines as they are not economical to repair.