Replacing the outhaul line of the Kenyon boom is fairly easy once you know what youre dealing with. Theres a stationary block near the mast end and a moving block with 2 beckets internally. There are two separate 1/4 lines. The line that attaches to the sail clew is 68 1/2 end to end and attaches internally to a becket on the moving block. The line that cleats at the mast end is 192. Its attached to the other becket on the moving block, goes through the stationary block, then through the moving block, and out at the mast. The line measurements are finished length. Buy extra line to make eye splices or other attachments. The thin white line in this photo is the messenger line.

Kenyon booms internal moving block

Since I had no idea how much line I would need, I sewed and knotted a strong nylon cord into the original line to act as a messenger. Once everything was out, I measured it and went to the store and bought new lines.....next time I can just buy the right length, sew it to the old line, and pull it through.

Ready to attach the new line

The measurements given for the lines are end to end, and do not including the extra length need for attachments. The pictures show the old lines attached with a big knot and a metal sleeve. Do yourself a favor and make eyesplices instead. Eyesplices are stronger and wont catch on the other lines inside the boom. I dont own a fid, but a piece of metal coat hanger worked well for making the eyesplices. The only problem I ran into was getting the new line through the internal moving block. During the process the moving block was pulled back into the boom, and the new line would not feed through it. I added a new messenger line to the clew line and pulled everything out the mast end where the lines were long enough so I could help the new line through the moving block.

another view