jib and spinnaker blocks

My friend recently purchased 909. The jib blocks are mounted on wood blocks on the rail of the boat. There is another block of equal size mounted to the side of the jib blocks for the spinnaker. We are interested in removing the second block and converting the jib to seat mounted blocks.
Our problem is that we can't seem to separate the two blocks. It looks like it is a single screw, that if it were removed the two blocks would separate. The screw comes out about half way and then continues to spin, but will not come out to release the other block.
Any ideas would be appreciated.

Thank you

Early Scots have nuts under the deck on the blocks. Later, they had self tapping screws. I think Dee at the factory told me that the method changed around boat 4000.

If you check with Harry or Dee, or the crew at the factory, they can tell you how to remove them.

Phil Scheetz
FS 4086

To separate the two blocks you probably need to remove the wooden support from the boat for a short period. THere is likely an embedded nut in the blocks.

If you crawl under the seat you will see (hopefully) so large styrofoam blocks. Normally, there are actually four large blocks (stacked 2 by 2) under each side. You can slide them apart a few inches (3-6") The split for the blocks of foam should be right under the location of the bolt. You can reach up with a socket set with extension or your hand (if you have long arms) and release the block.

It also likely that the wooden block is mounted with more than one screw, there may be a screw underneath the actual jib or spinnaker blocks.

WARNING: Watch the fiberglass straps holding the Styrofoam blocks in place, they can be very sharp!