The old 2-spring motor bracket is rated in Catalina Direct's Handbook for 60-80 lbs, 5-7.5 hp outboards. The boat has a 12 year old 4-stroke, 9.9 hp Honda outboard and a block and tackle to help pull it up. The wood mount has a SS plate that is attached to the bracket mounts with 4 SS bolts. The spot welds at the top of the SS mounts were cracked. I decided to replace the bracket since the 4-spring bracket is more suitable for today's 4-stroke outboards that average about 5-10 lbs heavier than the old Honda outboard. The 4-spring bracket is rated for 9.9 hp outboards weighing between 100-115 lbs. Replacing this bracket is in preparation for most likely replacing the motor within the next few months.
I mounted the bracket onto a 1/4" polymer board (also called Starboard) and then onto the transom using 3M Marine Grade Silicone Sealant. (Some have used a 1/2" polymer board but I had the 1/4" board left over from another project - mounting my solar controller.) I was also going to install half angles onto the inside of the transom but the half angles did not fit due to interference with the cockpit in the quarter berth stern area. I can mount a polymer or plywood board back there but believe it is not necessary. The transom looks in real good shape with no noticeable curvature/deterioration. In fact, after the installation, I stood on the top of the outboard (~200lbs) and there was no movement at all between the bracket and the transom - rock solid !
Initially had two glitches with the new bracket but both were easily resolved:
First, a close look at the second photo, above, there are two self-locking nuts positioned under the spring spindle. When I received the bracket from Catalina Direct, those bolts/nuts were loose and the bolt was too short (1 1/2") and did not allow proper thread engagement onto the self-locking nuts. The bolts left at least two nut threads not engaged and questionable if the nylon insert in the nut would function. I replaced the 2 bolts with 1 3/4" SS bolts and placed an additional SS washer in from the other side where the bolt head sits in the polymer mount's counterbored holes. This would take up some of the bolt length so the bolt did not bottom out on the spring spindle. That then allowed proper engagement of the nut threads - bolt threads then protruded out of the nut 2 threads. That solved this issue. I have since discussed the issue with Catalina Direct and they were going to check out the remaining 4-spring bracket stock they had to see if similar issues existed with bolt thread engagement. (By the way - the bolts on the lower end of the board mount had prper thread engagement - It was supplied with the longer bolts and no spring spindle is in that area.
Second, after the installation was complete, the new bracket was a bit stiff to operate - would not lock into the deep position. I worked it up and down many times but had a hard time getting the bracket to fully engage in the deep position. One of the two bracket arms would engage/lock into the slot but could not get the other. I tried a day or two later and brought a cheater bar to help nudge it into position. That did not help so much as just working the bracket some more up and down. Finally - the bracket engaged as it should locking it in the slots on both bracket arms.
The installation required no work on the tight clearance holes thru my transom - The new bracket has exactly same bolt hole locations as the older bracket. No need to use the block and tackle - the new bracket is easy to pull the outboard back up, though, I will probably keep the block and tackle attached as a safety in case the outboard ever comes loose on the mounts. I am thoroughly satisfied with the 4-spring bracket !
