How to travel VERY slowly with 2 motors

[freddofrog]

I’m support boat for a open water swim team and need to travel at around 0.5kn over 19km. Should take 6hr-ish.

What’s the best way to do this in terms of economy and preventing potential damage to the motors (over heating, plugs fouling etc). eg Just run on one motor and switch every km or just run on both. Alternatively should I just leapfrog every 500-1000m and wait till they catch up (though I’m not sure if the swimmers will agree to this strategy)

Actually if the wind is up and in the right direction I can actually drift faster than they can swim!

Btw it’s kevlacat with twin 90hp 2 stroke yammies (2005)

ta
ff

[trueblue]

Better if you change boats to something with a 4 stroke engine...

I would probably run with one engine, and if it fouls up the plugs then change to the other engine.

If you have access to a set of smaller pitched props that would help slow you down at idle.

[Greg P]

Run one at a time but trim the powering engine right up and leave the dead soldier trimmed in. maybe tow a bucket behind as well to slow right up.

[deadbeatloser]

buy a suzuki or yamaha four stroke that will do the trick the best;D

dbl

[SeaHunt]

Borrow a Minkota for the day.

[Crocodile]

What a privelege to contribute to sport that way.
I am an open water swimmer too, a little too old and slow for 19km though.
These guys will swim at about 4km/hr, which about 2knots.
This is still far too slow for your outboards.
I would experiment with towing something expendable in case you have to cut it free.
Is the event in fresh or salt water?
Where and when is it being held?

[FNQCairns]

What about turkey basteing out most of your oil and adding 1L (or more) of xd100, even if you make the xd as only 50% by volume of the oil that would be better than none also.

IMO it's worth trying to run on the xd100 as the major fraction for the trip just to stop the carboning up low revs and low heat will cause, the fouling of plugs is neither here nor there in comparison.

cheers fnq

[mlaagtho]

I troll on one Suzuki DF 140 all day (at Idle) with no problems

[Horse]

Tow a large drogue or Para behind you to slow down

[Hebb]

There is a product made which you can install on your motor. It is like a large flap that hangs down behind your prop. Is designed for slow trolling lures but if you are doing a lot of support work for swimmers could be usefull. Its called a trolling baffle. A mob called "MAGNUM" manufactures them? Phone 0414 321103. Got that info from an add in a fishing mag and am not promoting or recomending them as I have not used or sighted one. JUst heard about them.
Hebb

[snelly1971]

There is a product made which you can install on your motor. It is like a large flap that hangs down behind your prop. Is designed for slow trolling lures but if you are doing a lot of support work for swimmers could be usefull. Its called a trolling baffle. A mob called "MAGNUM" manufactures them? Phone 0414 321103. Got that info from an add in a fishing mag and am not promoting or recomending them as I have not used or sighted one. JUst heard about them.
Hebb

They are also sold by Solas....Think they are called troll a matic or something like that

Mick

[freddofrog]

This is only a once a year event so hardly worth buying any new gear for. I will look into the xd100 option but how much different do you think it will really make? In the end I'll probably just say stuff it, cross my fingers and hope for the best :-/

[FNQCairns]

IMO quite a bit of difference, esp to behaviour, nice treat for the engine also will under normal use start clearing away older deposits.

This oil technology is 10 years old, it's as good as any land based 2st oil you can buy so light years ahead of tcw-3s BUT your last sentence in all truth is probably where I would end up also due to the trouble of giving a shit, there is no way to know in any individual engine if the exercise may do harm to it's life span without heading much deeper into the exercise.

BTW running both engines together all the time will be kinder than running one and alternating due to the oversized props fitted for what it's worth at this speed, just slip one in to neutral every now and then and give it a kind rev up, then when all done do a 20 min cruise somewhere to clean it all out if you have time.

cheers fnq

[gofishin]

ff, I think fouling may be a problem with your main donks, maybe cooling too. Sea/drift anchors and prop baffles may help with speed, but won’t help the fouling. Why not do a trial run for a few hrs a few weeks b4 hand and work out what works?

Do you have a boarding platform b/w the donks, and a mate who has a 2 - 4hp 2 or 4 stroke? You could make, or get made, a small temporary o/b bracket the slips over the platform (top & bottom) & is secured by 2 bolts through the platform. S/S or even MS would do with a bit of 25mm ply b/w braces.

Run the small donk, lock it in place & just use your main o/b’s for steering. May need a few manual adjustments for windage (or kick your main donks in for steering corrections) but may end up a lot less maintenance hassle over 6 hrs.

Pretty sure I don’t have my bracket anymore, but used this idea successfully many times getting a 33’ fly bridge cat out of the canals at Broadbeach with a 4hp 2s (except used 4hp for steering too). Had to get under bridges, but then tide was so low that the duoprops were churning mud & rocks. It wasn’t 6 hrs though:-[ . I will have a look, if I still have it I will PM you if you are interested.
cheers

[cod muncher]

the only way to fix the problem is to ring em up tell em ya sick , and go fishing8-) 8-) 8-) 8-) 8-) 8-) 8-)

[polky]

dbl you don,t miss a trick do ya, that was pretty quick bud. suzie lover Polky.

[Chimo]

Or really the question is how to in spite of two motors and without a doubt GoFishing is on the money;D

I have moved about 14 m of pontoon a long way up and down two rivers and thru the GC Broadwater and did it with a 9.9HP running at about 1/3 throttle over a period of some 10 hrs for a fuel burn of about 25 to 30 lt

The 9.9 was on the back of a tinny lashed to the end of the pontoon so the total length was about 17.5 m and this setup gave steerage and good control with very small tiller adjustments, a lot like a big houseboat.

You have your two motors to use as rudders so just hang a small outboard on a simple right angle bracket or similar, bolted on somewhere on the pod between or even outside of one of your two motors and have a great day with your motors as the rudders and the motion to and from the race course and the small O/B as the power source during the swim.

PS Dont forget the pics of the day too please.

Cheers
Chimo