We run on Mercury Outboards!
UTC Ultra Thread 140 Denier is a very good general purpose fly tying thread. Its flat nature keeps it from building up bulk quickly but with a breaking strength of approximately #2 will allow you to pull a bit harder on hairs and when tying streamer flies. The flat nature makes it a great choice for the split thread dubbing technique like that used with the Stonfo Thread Splitting Tool. UTC Ultra Thread 140 Denier is recommended for hook sizes #6 to #14.