Honwave T3.8 IE - Auxiliary Engine / Transom Question

Alexo · 19 May 2015, 09:20

Dear All,
Good Day. A quick question if I may.
The Inputs:
1. Honwave T3.80 IE
2. Engine Honda 15hp 4T (47kgs)
3. Engine Honda 2.3hp 4T (12-13kgs)

I am taking the kids with the boat and an extra something on security would help.
Think of fitting an auxiliary engine sliding bracket on the transom and slide it there in case of need (i.e. in the event my main 15hp fails me).
The bracket is necessary as need to have some distance from the transom for the auxiliary as on the side, outside the transom, the Honwave (with inflatable floor)has inflatable flaps.
I will not have the auxiliary engine on the transom at all times but only if a need arises. However want to make sure that if a need arises, the transom will not break by the increased (2 engines) load.

Questions:
1. Can I use the Honda 2.3hp as auxiliary?
2. Would the transom take that load or would I strain it too much?
3. Maybe if I were to strengthen the transom by tying it with a rope to the seat?
4. Any other ideas on how to use the Honda 2.3 as auxiliary on my boat?

Thank you for your thoughts on this.

Best - Alexo

dave3235 · 19 May 2015, 09:51

Quote:

Originally Posted by Alexo

Dear All,
Good Day. A quick question if I may.
The Inputs:
1. Honwave T3.80 IE
2. Engine Honda 15hp 4T (47kgs)
3. Engine Honda 2.3hp 4T (12-13kgs)

I am taking the kids with the boat and an extra something on security would help.
Think of fitting an auxiliary engine sliding bracket on the transom and slide it there in case of need (i.e. in the event my main 15hp fails me).
The bracket is necessary as need to have some distance from the transom for the auxiliary as on the side, outside the transom, the Honwave (with inflatable floor)has inflatable flaps.
I will not have the auxiliary engine on the transom at all times but only if a need arises. However want to make sure that if a need arises, the transom will not break by the increased (2 engines) load.

Questions:
1. Can I use the Honda 2.3hp as auxiliary?
2. Would the transom take that load or would I strain it too much?
3. Maybe if I were to strengthen the transom by tying it with a rope to the seat?
4. Any other ideas on how to use the Honda 2.3 as auxiliary on my boat?

Thank you for your thoughts on this.

Best - Alexo

Hi your answer is on the transom plate,maximum engine weight.

kaman · 19 May 2015, 11:36

Hi I carry an auxiliary to both my Sibs - Honwave 3.5ae

http://www.rib.net/forum/showthread.php?t=60215

And Seago Eco 260.

http://www.rib.net/forum/showthread.php?t=67844

I'd feel naked going to Sea now without an Auxiliary.
A must have in my opinion if you are going to Sea in a small boat.

Alexo · 19 May 2015, 15:34

Quote:

Originally Posted by kaman

Hi I carry an auxiliary to both my Sibs - Honwave 3.5ae

Need for an auxiliary engine on a SIB??? - RIBnet Forums

And Seago Eco 260.

Seago Eco 260 gets an auxiliary and transom wheels - RIBnet Forums

I'd feel naked going to Sea now without an Auxiliary.
A must have in my opinion if you are going to Sea in a small boat.

Thank you Kaman.
I think I should be following your Honwave arrangement however I am not sure I understand. Why did you arrange for aux engine to be on the side and not back? Do you think my idea for sliding bracket so for engine to mount on back will strain transom?

In general are you against my idea of fitting a bracket on the back so to mount the 2.3 in case I need to?
Thank you.

kaman · 19 May 2015, 16:07

Only reason I mounted the auxiliary out over the outside of the tube was due to lack of space within the confides of the transom.
Quite simply the 50 plus kg Tohatsu 20hp is too heavy to lift off if you have a break down at sea - therefore i couldn't do this and swap it over for the Auxiliary.
As I dry launch off a trailer with transom wheels, space on the transom is compounded further with the wheel mounting bracket.
The only option was to have an outrigger to carry the auxiliary on deploy on the outside of the tube.
Not ideal but it has served me well over the past few years and I wouldn't be without it now.
It is possible to have two engines on the transom but not if you have launch wheels / brackets.
It's one or the other in this respect.

Alexo · 19 May 2015, 17:32

Dear Kaman,
Thank you for your reply which helped me a lot. The inflatable floor Honwave uses only a small part of the back of the transom for the fitting of the launching wheels thus believe there will not be a problem fitting the auxiliary bracket. This may mean one of the wheels stays inside the boat when I am travelling if I have the aux engine mounted.
The key question here which I presume is answered is if the transom will take the load of the 2 engines mounted, one being mounted on the auxiliary bracket. I understand from feedback it will.
Same like you I am not planning to lift my heavy 15hp main engine to move it if it fails me in the middle of the sea cause it is too heavy.
I will be testing to see how the aux fits next to main engine and see how the bracket fits on transom; these brackets seem to be bit expensive thus will need to do some market research.
Thank you for your time and valuable feedback.
Best! Alexo

chipko · 19 May 2015, 18:35

We also have a 2.3 Honda auxiliary for longer coastal trips. Ours is kept in a padded bag stored forward and under seat. When required we slightly loosen main (20hp) and slide sideways along transom by about 75mm. This gives us just enough room to mount aux. and allow steerage. Transom weight is exceeded by about 5kg but only making slow headway on aux. so stresses are fairly light.

Stevem · 19 May 2015, 19:36

I have been thinking of fitting an aux recently and was going to try exactly that Chipko. Ive got an Aerotec 380 with a mariner 15 2 stroke and am sure one would fit if i modified the top of the transom so the 15 could slide out of the way to fit the aux. Am looking for a skinny 2.5-3.5hp aux. Nice to know this is doable.

Alexo · 19 May 2015, 20:05

Dear Chipco and Stevem,
Thank you both.
Unfortunately I can not slide the main engine as the honwave inflatable floor has at the bottom of the transom both left and right inflatable flaps allowing space in the middle only for one engine. If I am to fit the aux it will have to be with bracket so to pass these; about 30 cm away from transom.
I believe the transom plate reads 70-80 kgs max weight (I will read when I inflate next). Main engine at 47 kgs and aux at 13 (60 kgs in total), I am well below the max level allowed thus I should be OK.
In any event I will have the aux in the boat and will only load if necessary.
Thank you.

chipko · 19 May 2015, 20:30

Stevem,
There's more room on our Zodiac, but we also have a 380 Aerotec and it is still just possible without any transom mods. Less steerage available (one way) and no reverse as the little Honda needs to spin round.
I think a long shaft aux. would work better on the 380 as you could bolt a riser plate to square off the sloping transom top at the sides.
If you're feeling flush a Torqeedo 1003 would be a good option as they are both light, skinny, and modular.

Alexo,
I can appreciate the extended floor tabs causes you additional problems and the need for an outboard bracket - some of these annoyingly rattle badly by the way.
My post really was just to say it is possible, though not ideal, to carry an aux in the boat and mount it on the transom while at sea if required. We've only tried this as an excersize though, albeit in quite a swell, and may not be as easy in an emergency situation.
Good luck.

Stevem · 20 May 2015, 05:48

Thanks for the info.

Alexo · 16 September 2015, 13:32

Quote:

Originally Posted by chipko

We also have a 2.3 Honda auxiliary for longer coastal trips. Ours is kept in a padded bag stored forward and under seat. When required we slightly loosen main (20hp) and slide sideways along transom by about 75mm. This gives us just enough room to mount aux. and allow steerage. Transom weight is exceeded by about 5kg but only making slow headway on aux. so stresses are fairly light.

Chipko Hi.
I know this is an old thread but would really appreciate it if you could possibly at some stage (if/when you have some time) you could send me a picture of the padded bag yu have made for your aux Honda 2.3 HP as I wish to make same and carry the engine inside the boat as Aux.
Thank you so much.

chipko · 17 September 2015, 00:43

Hi Alexo,
We store our little Honda 2.3 aux in a standard Yamaha 2.5 padded outboard carry bag......I don't think Honda make a full padded bag. A bit of a tight fit but it will just go in ok.