weight of outboard on HDC transom

[passagesfromtheheart]

I have a Yamaha electric start 9.9 hp outboard engine on my HDC -- does anyone recall if 9.9 hp is what Com-Pac recommended for the HDC? It seems the engine is significantly heavy and I worry about all of the weight on the boat's transom. Plus, taking the engine off of the boat for servicing would be something I don't think the First Mate and I could do, either.

Sailboatdata.com notes the displacement of the HC/HDC (without inboard engine) at 2500 lbs. My former Com-Pac 23 MK IV displaced 3k lbs and I only had a 5 hp outboard on that boat. I sailed on an inland lake, so perhaps given this situation, this hp of engine was sufficient -- however, that said, in other bodies of water where tides/currents are present, perhaps the 5 hp would have been underpowered for the 23. I don't know as I have no experience in that regard.

As my HDC weighs less than my 23, I'm considering losing the 9.9 engine and going down to a 5 hp like I had on my former 23. I'll be sailing my HDC on the same lake as my 23, so would assume I'd be OK.

The only thing I'd miss is the electric start on the 9.9. It is pretty slick -- I have never used an outboard with electric start before, so gotta say, it's a treat to not have use that pull cord to fire up the engine. (Doing that kinda brings up bad memories from starting my cantankerous lawnmower from back in the day. :-D. )

Thoughts? Is the HDC transom sturdy enough for the 9.9? I see two other 2014 (same year as my boat) HDCs, with outboards, on the market today, and they, too, both have 9.9 outboard engines...which makes me think this might have been what Com-Pac recommended for these boats.

Mahalo, friends!

[brackish]

Random thoughts.  I too had a 9.9 with electric start on my 23 IV, it was on the boat when I purchased it. It was problematic for a number of reason that you have mentioned, but in my case if I had more than two people in the cockpit, it shipped water up the scuppers into the back of the cockpit.

My 23 was listed at 3200 lbs. displacement.  I called and asked when and why it was raised from 3000 and Gerry (I think) told me just some weight creep over time that they had finally revised the specs. 

I did the calculation for required HP based on the 3.2K as one of the variables and it came out to be just below six HP for attainment of hull speed. Can't remember the formula had to look it up at the time.

So I changed the 9.9 which weighed 104# to a 6hp 25" shaft sail pro that weighed 59# and life got much better, fixing my problem and addressing yours. It has never been underpowered but then most of the time it lake sailed.

Just recently, even with the lighter motor, I had an incident whereby the polymer mount plate on my original, Hutchins supplied motor mount, broke off and the motor went down.  Fortunately I was at the dock when it happened,  had a anti theft cable attached to the motor so it was only partially submerged and only required a minimal amount of work to recover and get it running again. It seems most of these mounts were designed back in the two cycle days and are not really good for the heavier four strokes. So always, the less weight the better unless you reinforce your mount plate in some manner.

Hopefully some HC owners will address your question more specifically, but my advice would be to go with the least weight possible on that mount.  Good luck with your new HDC.

[Vectordirector]

Hi,

I have a 2024 Horizon Cat options sheet from the now defunct local dealer.  It shows an upgraded motor bracket for outboards over 80lbs at $699.  If you have that you should be ok. 

The 9.9 was specified for owners who needed electric start and power tilt.  We all get there someday.
It is really only about 40 lbs more than the 6hp versions if you don't need to add a battery. 
I would refrain from towing the boat with that heavy outboard hanging off the transom for any long distance.

You can make an engine hoist with a mainsheet and boom. 

Fair Winds,

Bryan

[brackish]

This is what you do not want to happen to your mount plate with the motor on and running. Not in gear just running in neutral and it broke when I pushed the choke in, so maybe I pushed a little too hard.

[Vectordirector]

Yikes!  I read somewhere that those mounts don't last long in the sun. 

Bryan

[kickingbug1]

     i would sell the 9.9 and get a 5 or 6.  i got rid of my 4 hp merc (60 lbs} and replaced it with a 2 stroke johnson 4 (35 lbs}

[passagesfromtheheart]

Thanks so much, everyone, for all of your input -- and brackish, I'm so sorry you had that situation with your bracket breaking -- but so glad to hear that you were able to retrieve the engine!

Bryan, so how do I know if I have an upgraded motor bracket mount? Are you able to ascertain from my video, per link shared below, if I have one? (In the video, there is quite a bit of footage, early on, of the engine and motor mount.)

From what I learned about the boat's history, she came from Indiana, went to Virginia, and then to Alabama, and then to Nebraska, and then to me.

I know, from the PO, that she was hauled from Virginia to Alabama, then Alabama to Nebraska, with the engine on the transom the entire way. Also to me with the engine on the transom.

That all said, the PO explained to me that there is a special locking nut on the engine/motor mount/bracket to help prevent the engine/motor from jostling up and down and such whilst underway/being towed. However, I admit, I still have concerns.

I will have to crawl back aft, under the port side cockpit bench, to see if there is any special backing plate there.

I am really concerned now. I do not see any cracking or something askew to indicate there is an issue...but, nonetheless, again, I am now exceedingly worried about it.

[brackish]

A friend in Florida sent me a replacement mount plate as pictured to replace my broken one.  He never used it, needed to make a custom plate to fit his motor.  That was good because I had no luck in finding one from the original manufacturer.

It also concerns me as it is slightly taller and while that does not affect performance in any way, it does put the breaking point which is the upper bolt line under a little more strain due to the force moment being slightly greater (mass x distance).  However the first plate lasted twenty years always exposed to UV which may have been a factor.  I am thinking of making a plate of laminated Ipe wood which is very dense with no long grain lines.

[Vectordirector]

Hi,

I just watched a few minutes of the video.  That mount looks like it is fine. It didn't move at all when you were towing it to the ramp.  Those 9.9 motors are very popular amongst the pontoon peeps on horsepower restricted lakes like the one I grew up on so you could probably sell it for enough to get a new 6hp if you wanted. 

It is really up to you if you prefer the electric start and all that brings.  EFI is a major plus in these as you avoid he carburetor issues with ethanol gas and winter storage. 

I would try it for a season and see if you want something else.
It is probably overkill for the boat but the electric start is really nice, makes it as easy as a diesel. 

I can't think of anything lighter with electric start.  Tohatsu has an EFI 8hp but it is pull start and not much lighter. 

Nice looking boat, hope it works out for you. 

Bryan