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Outboard Motor / Hobie TI Application Guide & 403 Comparison
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Author:  fusioneng [ Thu Sep 13, 2018 5:19 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

I also had my motors mounted pretty high, I never measured but am guessing my Honda’s were around 6” above the gunwale. I had the short shaft honda 2.3 outboards, (2), mounted near the rod holders.
I had the motors mounted very close to the hull and tilted inward around 5-7 degrees so the props are under the hull somewhat.
Keep in mind I had a modified planing hull with much more flotation , (100 lbs extra flotation), and when underway, (planing) the boat ran much higher in the water vs most TI’s.
We were able to start the motors with the bow on the beach, and normally beached with the motor running. With two motor I could steer somewhat with rudder up and using motor rpm to steer in very shallow water, (lots of very shallow water around here at low tide).
One other trick we used in shallow water is to lock the rudder up around 15 degrees from horizontal and steer with just a small part of the rudder, (yea you can do that). We often sail thru 8”-10” of water, (lol usually not on purpose).
When solo I only ride in the front seat, (can’t stand that sailcontrol line on my neck), I had throttle extensions so I could operate the motors from the front. For a while I had extentions on the tilt up and starter ropes, but never used them, so they were removed, (too many ropes). We typically started the motors when we pulled out and just let them run all day, (Idling when not actively using them for power). Then shut them off when we came in.

EDIT: We typically got around 3 hrs of runtime out of the motors per tank of gas (1 tank = 1 liter), (longer if we used them less, (motors were not primary propulsion on the boat), actually I don't recall having to fill up the tanks on the water very often, (though it wasn't difficult, it was still a little bit of a pain).
One thing you will find out with the Honda's is once they warm up, the idle goes up, and the clutches don't dis-engage completely at idle, as a result with the throttle all the way down, we couldn't go any slower than around 6-7mph, (with the motors idling), I typically had to kill one when coming in the harbor. Never did solve that one.
One other thing we did for a while was to stuff a big wad of silicone tubing into the exhaust port, of various lengths, (looked like whiskers). This made the motors totally silent, (lol we called it stealth mode). But we wouldn't try to run the motors at higher rpm with that setup, as it might overheat, (we limited to 1/4 throttle). That was fun for a while, but I ended up removing the tubes, at low rpm the motors are not loud anyway, we can easily talk over the noise without any tubes at all. Here is a video with the motors running, (no silicone tubes), you can barely hear them, (that day was a good idle day for the motors, they were idling very low that day), normally in that situation I would have need to kill one motor.


Here is a video of the boat planing on the water, (notice how high it is riding in the water, and the bow is out of the water). Normally at that speed, (without the hull mod), the stern is completely underwater because we are above the hull speed of the boat, (8.6mph is the hullspeed of the TI), and the stern wave has overtaken the stern without the hull mod. The hull mod delays the stern wave and moves it back a couple feet.

If I ever do another hull mod, it will be wider and flatter, (that one wasn't quite right, (first attempt)), and will be the full length of the hull, (making the boat 20.5 ft long), giving me an additional 200 lbs of flotation.

Author:  head_dunce [ Thu Sep 13, 2018 8:10 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Thanks. I think I'm going to go plan B since I'm not sure how high to raise the motor. I'd like to have it as high as possible since there are some very cool and unexplored shallow areas around here (Middle Caicos.)

Plan B -
I'll get 4 of these and bolt them to a wood board that I can cut until I get the right height. I can get wood at the hardware store on the next island over.
https://www.framingtech.com/corner-guss ... es-4-holes

Author:  pro10is [ Thu Sep 13, 2018 9:25 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

If you mount the motor too high you run the risk of a form of cavitation if the prop starts to suck in air from the water's surface.

Author:  head_dunce [ Thu Sep 13, 2018 9:46 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Yeah, I understand that. My last boat was a 240EFI Merc Jet in a Sugar Sand where cavitation would happen when I'd beat on her. There's also some bearing that needs to be submerged on the Honda 2.3 to keep cool that I've read about. I'll have to figure out the height once I bolt everything on and take it for a spin.

Author:  mcoop57 [ Thu Sep 13, 2018 11:24 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Mr Dunce, the back of my transom (where the motor grips) is dead even with the front edge of the rear hatch on my T.I. The height of my transom from top of gunwale is 8.75 inches as measured with Stanley tape. It worked very well with the Honda, for all of the 13 hours(over six months) that I owned it. It’s kind of funny now, if I start the motor with no one in the boat, you can really hear the exhaust from the Suzuki. Once we climb aboard it seems to be in the perfect position, nice and shallow for efficiency, yet never has an issue with digging in.

Author:  head_dunce [ Thu Sep 13, 2018 12:09 pm ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Thank you!

Author:  stringy [ Thu Sep 13, 2018 4:10 pm ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

If you want to avoid waves hitting your mount then the bottom of the mount should be around 2” above the gunwale.
You’ve seen this main thread on outboard mounts? https://www.hobie.com/au/en/forums/view ... &start=330
On p23, second last post, is Jim Powers mount which is a great evolution of the ideas so far.

Author:  fusioneng [ Thu Sep 13, 2018 5:29 pm ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

I think the final motor height is a trial and error thing depending on where on the boat the motor is mounted, how far away from the boat the motor is mounted, (some mount them way out). So there is no one size fits all.

So it’s probably best to design so you can dial that height in. The main factor is cavitation, which is loud and easy to identify. Plus it might not cavitate on level water, but cavitates badly when on a left or right tack when sailing, (that was a problem on my first motor).
Also it make a difference if you have a shaft mod or not. If you watch my video you will see a white thingy on my motor shafts, those eliminate most drag and eliminates most cavitation, (keep in mind all outboards are designed to be mounted behind a transom, (behind the boat).
It might be better to design too low, then trial different shims until cavitation starts, then lower down slightly, then finish the mount to the final height on your boat.
Just suggestions that’s all.

Author:  head_dunce [ Fri Sep 14, 2018 5:30 pm ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Thanks for all the help. I've ordered the brackets and a bunch of different size 316 ss bolts, washers, nuts, etc. to get this fabricated with a wood board I can pick up on the next island over. I'm going to be in the US for a night in a few weeks, so I'll be able to pick up everything I ordered (UPS Store's are great!) I also have the motor coming via cargo ship on a freight forwarder in a few weeks. So I'll report back once I can get everything together.

Author:  pro10is [ Tue Feb 12, 2019 11:09 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Note: I recently added this post to another thread. I generally don't like to crosspost but it has much relevance here:

I've created a chart for TI motor suitability within varying weather conditions. The Torqeedo 403 vs gas outboard motor section is based upon my experience with both motor types mounted on a TI. For the trolling motor, it's based upon my past experience with such motors on boats other than the TI and projected for use with the TI. This reflects my opinion only but I believe it to be quite accurate. Others may have different opinions.

The difference between the two Torqeedo ratings is that the 403/403A models use a 320 Wh battery and the 403C/403AC use a 915 Wh battery. The larger battery allows you to run the motor faster and longer for a considerably greater safety margin in bad weather. The Trolling motor battery is assumed to be a typical 12V lead/acid heavy-duty marine battery. All batteries are assumed to be near a full charge.

The gasoline engine ratings assume a nearly full tank of gas (1 liter) which typically gives an hour's worth of run time. Of course, more gasoline can be carried, but I can tell you from experience that it's difficult to refill the tank in very bad weather conditions.

The ratings are not only based upon available torque, but also the motor's ability to maintain adequate torque over the time and conditions it must typically operate, especially in potentially dangerous weather.

The ratings assume you are running without the sail. Running with the sail would improve the ratings in good weather conditions, and possibly in bad weather conditions provided you know how to sail properly in bad weather. If not, running with the sail in bad conditions could possibly make things worse.

The bad weather scenarios assume you are making a run to shore with no sail within an hour's worth of running time. If you're using the TI in areas where dangerous weather conditions can suddenly occur and you are over an hour's distance from the nearest shore, then I would consider that to be beyond the reasonable safety range of this particular boat even with a motor (although I admit to doing this myself).

The ratings are as follows:
E: Excellent, the motor will perform without problems.
G: Good, the motor will be adequate if not ideal in these conditions.
F: Fair, the motor will be performing adequately but is near or at its limits.
P: Poor, the motor may still help but it is beyond its limits and may not be able to overcome the current conditions.


Author:  head_dunce [ Wed Feb 13, 2019 6:14 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

I've been running the Honda 2.3 for a while now. It works well. I've also got a spare 1.5 liter bottle for extra fuel I've already used a few times. I need to figure out a way to prevent the wake the motor produces from going over the tail of the boat, and I know that's discussed here, but the water it puts in the hull isn't much so it hasn't been a big worry.

Had the TI out in 200ft of water a couple weeks ago when there was no wind or waves, which made the outboard very useful. Spent a couple hours fishing while a humpback whale was nearby taking a nap. Hearing it take those huge breaths was very cool! Some video here https://www.facebook.com/headdunce/vide ... 465616367/

I like the idea of the Torqueedo, but I've heard too many stories of guys having to send them in for repair.

Author:  pro10is [ Fri Feb 15, 2019 7:41 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

I really wouldn't worry about the reliability of the Torqeedo. Mine has proven very reliable over the years and has never let me down on the water which is much more than I can say for the many gas outboards I've owned over the years. There's far less to go wrong with an electric outboard since they have no need for a fuel system.

I only had one minor problem with my Torqeedo which really did not affect the operation. The tilt switch would not always work, but it never stopped the motor from running. I sent it to Torqeedo to be fixed offseason, they had it back to me in 10 days. That problem nor any other has ever occurred again after hundreds of hours of use.

Author:  head_dunce [ Fri Feb 15, 2019 10:51 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

I'm on a remote island, only about 100 people here. Sending something in to get fixed isn't really an option between shipping and duties. An outboard I can fix. There have been quite a few people with problems on the Torqueedo group on FB.

If I was to do it over again, I'd look at mud motors so I can get shallower.

Author:  pro10is [ Sat Feb 16, 2019 5:42 am ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

And there have been more than quite a few people who have had problems with gas outboards. The new Tohastu I purchased for my TI turned out to be a total failure as I've documented in this thread. All I'm saying is that overall I believe the Torqeedo to be more reliable than a typical gas outboard based upon my years of first-hand experience with both.

Your situation about being on a remote island is certainly unique and would not apply to most. Normal turn around time for getting a Torqeedo fixed is less than two weeks, even faster if there is a local dealer. When I brought the new Tohastu to a local dealer for warranty work, he said he couldn't get to it for a month. So it's all relative.

Author:  Moedy [ Tue Mar 05, 2019 11:30 pm ]
Post subject:  Re: Outboard Motor / Hobie TI Application Guide & 403 Compar

Torqeedo plans to release a new version sometime before summer. There's speculation that it's way more powerful than the 403. It might be a game changer to decide between gas and electric

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