Mounting an Auxiliary

[Matt]

My Cobra has a bit of a swim platform on the back and I wanted to mount an auxiliary engine - which I also wanted to be a standard shaft, not long. Partially because I have one, and b because I didn't want it sticking "too far" out the back.

Anyway, I came up with this which puts the prop virtually as deep as if I had a long shaft.





(Blue smoke is from the 5hp running premix. )

[spartacus]

Looks tidy. Thanks for clarifying that your Mercury wasn't running like a bag of spanners!

Good to see you have a rope tether on it too before it ends up in Davy Jones's Locker!

Run that auxilliary with fresh water regardless of whether you use it when you're out. The tell-tale blocks easily I've found and the little Mercury/Mariner water-pump housing (under the stainless plate) clogs up with salt crystals. This was my Mariner 4hp back in April this year when I renewed the impeller after 2 years. Bear in mind this is flushed with fresh water every trip. The impeller was in perfect condition. I'm looking to use salt-away or similar next season and add direct to the barrel, so avoid muffs altogether.

[Matt]

Originally Posted by spartacus

Good to see you have a rope tether on it too before it ends up in Davy Jones's Locker!

Absolutely, this is not my first rodeo, even though I do frequently still find myself in situations where I should have known better.
I would like a tidier solution, though.

You make a good point about flushing etc - especially since I always fire up the aux and put some load on it to make sure it's all working properly - be a shame to need it and find it's not in the mood.

The big motor will get a new waterpump this year since it's unknown age - and the little one - generally I am very religious about flushing it, but even so, it's been in there for 4 years, despite having little use, so I think I'll freshen that one up too.

The 5 - had hardly been used when I got it - the powerhead looks like brand new. But the poor old gearbox & waterpump had suffered terribly - culimating in it needing new "everything". I don't have a pic of the waterpump, but this was the inside of the gearcase......

[Peter_C]

Have you considered rigging up a remote throttle? Remote shifter would be nice too, but is more complicated.

Our kicker mounts are completely different but mount at almost the exact same location, except my transom is very narrow and the main and kicker are extremely close. I just used scrap plywood to build it, wrapping it in fiberglass, but did have to buy a new longer U-bolt for the trailer tie down on the port side. Now I wished I had gone with a short shaft too, as it doesn't need to be as deep as it is, and it would be usable for a portable SIB.

[Matt]

No, but I do have one of those outboard tiller extensions so I can steer and throttle from the back seat.

[Peter_C]

You might find it more comfortable to steer from the helm with the main and keep the kicker straight or with a little turn of the tiller to starboard to correct for the offside thrust. I *must* tilt my main up for clearance, but am able to keep enough of the leg and all of the skeg in the water to steer with. You have more options than I do.

A lawnmower type throttle allows one to control the kicker speed from the helm. I just reach over and adjust speed on the tiller as needed from the helm *shrugs* small boat.

[Matt]

I hear you - but the intention is that this is only needed in emergencies, not for general trolling around.

[Peter_C]

I agree. I have a kicker because I boat in remote areas where self rescue may well be needed. A 20 mile trip away from the launch ramp is an hour at a 20mph cruising speed. On the kicker at 5mph that same trip becomes 4 hours. Sitting comfortably at the helm starts making more sense after the first hour.

[Matt]

It's OK - have used it for > 1 hour before on the other boat and it's all fine. The tiller extension works well.

[Matt]

Although I have to say, you've got me thinking. I could have a tie bar on the steering to the aux motor. But equally, on the list of jobs to do, there are other much higher priority ones.

[Nasher]

Don't think I'd want to use the main engine to do the steering when using a small aux engine.
It would mean having the main engine leg and prop in the water causing drag which the little aux could do without.

I'd want the main engine tilted right out of the water where it's not causing drag, and sit on the tube with a tiller.