Enforce Transom on R 23

[sunfish]

Hiour 23' Ranger (1976) shows some mini gaps between hull and transom. But it is something that keeps us looking at it as an issue that ahs to be solved soon.After a major complete renovation (2003) we had decided to replace the outboard with a 9.9 4 stroke - did reinforcement inside and a had a special block (plywood) shaped to the best angle to get the motor straight in the water.As we have not found a perfect molding yet to finish that part, we have now seen some movement between hull and transom. Anyone some ideas how to proceed best(procedure and material) - and what is your experience on this particular spot?

 

[Barnacle Bill]

Too much weight

It is hard to definitively comment, but I would guess that the 4 stroke is too much for the stock transom. If you are getting separation between the transom and the deck at the stern, you probably need to go inside and fiberglass the joint up (inside corner) and also make sure the transom surface inside has proper additional support to handle the extra weight (such as a plate so that the load of the motor mount spreads out the load).A Ranger 23 is not a very big boat and certainly a 10 HP outboard is not required to move it along at hull speed. I probably would have picked something smaller, but perhaps you have your reasons for going so large.

 

[Howard19003]

transom stress?

I too have a heavy O/B (Honda 7.5hp 4 stroke.. same as 9.9) but it came with the boat so I live with it. I think 5 or 6hp would be plenty. Fortunately I have the original pole type motor mount. I believe Gary Mull artfully designed this mount to transfer the stress and torque through the thin (diaphram) transom into the heavier built cockpit liner. Replacing this design with a "bolt on" mount may put stress into the transom it was not intended to take. With this type of mount the torque could probably rip the transom apart as the lower unit pushes forward it tries to twist the top of the mount (and transom) backwards. Even if the inside of the transom is reinforced with plywood, and fiberglass, the weak point will be at the edges of the transom where it is attached to the deck.