Aux Engine Questions

[apeltim]

Hello everyone. I’m new to the site. I’m retired military living in Tonnarella, Sicily. I own a 19' Carolina Skiff w/90hp Merc. I’m thinking about getting an aux engine for trolling, but more importantly as a backup motor. I do not want to get stuck offshore in the Tyrrhenian Sea without a way in.<br /><br />I’m considering a new 4hp 4-stroke Tohatsu. I chose this size/type because of the light weight (56lbs), the four-stroke torque, and I won’t need to haul an extra gas tank for a two stroke engine. (The Merc is oil injected). The Tohatsu seems to be the most reasonably priced new engine. <br /><br />I have several questions if anyone can help:<br /><br />1. Any info concerning Tohatsu? Specifically their small motors.<br /><br />2. I’ve found several types and brands of adjustable aux engine mounting brackets. I noticed quite a difference in price between the brackets designed for four vs. two-stroke engines. My question is, can I get away with using a lower priced two-stroke bracket, when the four-stoke engine is only 4hp?<br /><br />Also, I’d appreciate any info from boat owners that have gone the aux engine route…pitfalls, lessons, etc… <br /><br />Obviously I know squat about boating; however, if you need any gouge on Italy, especially Sicily…I’m your man!<br /><br />Thanks…<br /><br />TGA

 

[tashasdaddy]

Re: Aux Engine Questions

if you are going into the ocean, i'd want somtething a little larger. as an emergency motor. the big ones only quit when you need the them most. high wind, rough sea, 4 hp may not be able to handle it. i would also have on baord a sea anchor, to keep the bow into the waves in emergency.

 

[apeltim]

Re: Aux Engine Questions

Tashasdaddy,<br /><br /> Thanks for the sage advice. Your comments about engine size check with other correspondence I’ve read. I intend to bump-up to a 4-stroke, 6hp. They’re not much more money and about the same weight.<br /><br />I looked at the sea anchors…looks like a 45 dollar nylon bag with straps. I agree I need one; however, are their substitutes that work as well. You know…improvise, adapt, and save. Thanks again for your response.

 

[dajohnson53]

Re: Aux Engine Questions

If you're going to use it as a trolling engine (and maybe even for the emergency use), I really recommend getting a steering linkage to the main engine. It's a lot easier and more comfortable to steer from the main helm area. If you really need to steer it from the back, you can disconnect the linkage and steer it with the tiller handle. I have EZ Steer brand and am very happy with it. There are others.

 

[roscoe]

Re: Aux Engine Questions

4hp, 6hp, both are too small.<br />9.9 or larger, long shaft, or extra long shaft, mount directly on the transom, skip the bracket.<br />Make sure the prop of the kicker is below the hull of the boat or you will lose most of the thrust and steering.

 

[nanoa]

Re: Aux Engine Questions

I have a 20 foot aluminum boat with a 8 horse yamaha it is plenty of power for my boat it pushes it well in a sturdy wind tahatsu is manufactured by nissan I believe or vise versa cant remember which anyway these are quite reliable motors and have been used for off shore use for years

 

[apeltim]

Re: Aux Engine Questions

Thanks to all for the advice. Now all I have to do is find someone who'll disassemble and ship a 9.8 Tohatsu to a military FPO box that has a 70lb weight restriction. It looks like I’ll have to shop locally…god help me!

 

[apeltim]

Re: Aux Engine Questions

Reference the suggestion to skip the mounting bracket…please excuse my ignorance, but there doesn’t seem to be enough room on the transom for both the aux and main motor. Can I move the main slightly to one side of the transom to accommodate the aux, without affecting performance? Thanks…

 

[Solittle]

Re: Aux Engine Questions

Best not move the main off the centerline as it will have a big effect on handling - better get the bracket. <br /><br />Oh - and I'll add my vote for around 9.9 hp on the size.

 

[apeltim]

Re: Aux Engine Questions

Originally posted by SoLittle:<br /> Best not move the main off the centerline as it will have a big effect on handling - better get the bracket. <br /><br />Oh - and I'll add my vote for around 9.9 hp on the size.

Copy all! It will be a min of 4-stroke/9.8hp, and I'll opt for the bracket mount. Thanks...<br /><br />TGA

 

[tashasdaddy]

Re: Aux Engine Questions

tga, when you mount, consider weight distribution, as you are adding wieght to one side. what can you move to the other side to counter that weight. i assume, you are self bailing or have a good bilge pump, with float switch.

 

[apeltim]

Re: Aux Engine Questions

Originally posted by tashasdaddy:<br /> tga, when you mount, consider weight distribution, as you are adding wieght to one side. what can you move to the other side to counter that weight. i assume, you are self bailing or have a good bilge pump, with float switch.

I briefly considered weight distribution, but figured it wasn’t a big deal. Guess I better think again, since I’ll be adding about 85 pounds to one side. I have a bilge pump, but I think it’s manual only. There is an on/off switch…no auto position, so I assume no float switch.<br /><br />I have a live bait-well on the port side stern. It looks like it could hold about 10 or more gallons of water (gotta check). Since H2O is 8.3 pounds per gallon, I figure if I keep the bait well full and mount the aux on the starboard side, that should more or less evenly distribute the weight. However, there is the torque to ponder…and now we’re quickly approaching my math skills envelope.

 

[ondarvr]

Re: Aux Engine Questions

Not sure which model of Carolina Skiff you have, but most are very stable, the weight won't make that big of a difference. On my 19' CC (not a CS) I've had 50HP, 90HP and 200HP main motors at different times and 6hp, 8hp and 9.9 kickers. It does make a difference in how it sits in the water, but not a big difference. Even just moving a small amount of gear around in the boat easily compensates for any change in the balance due to the different motor weights.

 

[apeltim]

Re: Aux Engine Questions

Originally posted by ondarvr:<br /> Not sure which model of Carolina Skiff you have, but most are very stable, the weight won't make that big of a difference. On my 19' CC (not a CS) I've had 50HP, 90HP and 200HP main motors at different times and 6hp, 8hp and 9.9 kickers. It does make a difference in how it sits in the water, but not a big difference. Even just moving a small amount of gear around in the boat easily compensates for any change in the balance due to the different motor weights.

1999, 186 Sea Chaser. I'm relieved to hear, "no big difference". I was having visions doing the "Hobby-cat" maneuver to offset weight. Thanks for the post!

 

[tashasdaddy]

Re: Aux Engine Questions

don't consider your live well weight, as it is consistent changing. the water in the live well, will stay the same as the outside water level. when you power up to plane, most of the water in the live well drains out. basically it's just a hole in the water, to store fish. i've seen a lot of boats planing with a out of balanced load at a 5 to 10 degree list to port or starboard. make for very poor handling, especially in rough water. you will probably have to experiment, with your on boat, to get everything right. in the past, i've had to move batteries forward (if you do increase the size of cables) fuel tanks, etc.

 

[apeltim]

Re: Aux Engine Questions

Originally posted by tashasdaddy:<br /> don't consider your live well weight, as it is consistent changing. the water in the live well, will stay the same as the outside water level. when you power up to plane, most of the water in the live well drains out. basically it's just a hole in the water, to store fish. i've seen a lot of boats planing with a out of balanced load at a 5 to 10 degree list to port or starboard. make for very poor handling, especially in rough water. you will probably have to experiment, with your on boat, to get everything right. in the past, i've had to move batteries forward (if you do increase the size of cables) fuel tanks, etc.

Wow! This is getting complicated. I think your right, I'm going to have to put on the aux and make adjustments from there. I will try to mount the aux bracket as close to centerline as possible. Thanks again for the info.