I usually don't bother with an outboard on my tender when at home (rowing is cheaper than a gym membership) but decided to change the impeller on my old but little used and very good condition Mercury 3.3 yesterday as last minute maintenance before heading off to Airlie Beach tomorrow.
This requires removing the bottom of the leg held on by two small bolts. Despite my religious flushing after each of the motors rare outings and making sure it was put away dry both bolts sheared. They look well and truly stuck in there and I don't have the time to play with easy outs whilst soaking in WD-40 or something for three days.
The price of water snake outboards has long looked attractive as well as the advantages of not messing with two stroke fuel and leakages and smells into the back of the car/yacht from the tank and carburettor.
It only has to push a small inflatable although I want it to work with a headwind or adverse current with 2 lightish adults and a child.
A replacement will cost at least 1500 or 900 for a Parsun and stock is a problem on short notice.
Anyway I bit the bullet and ordered a 50 amp hour lithium to be delivered to my North Queensland destination Sailing Club and will be picking up a 54 pound thrust Watersnake.
The exposed nature of the electrical connection to the battery is a bit of a worry when spray is around particularly with a lithium and yes I do have concerns about the power of the thing as well as how I'm going to keep the battery charged. A 50 ah deep cycle would however be too heavy and of course only provide half the energy.
It's only a $700 investment and I don't mind trying something new which may offer advantages.
Didn't help however that when I rang BCF in Cannonvale/ Airlie Beach the guy said that he also worked in the fire department and I should not use lithium due to the risk of a thermal runaway fire. His comment was that if I managed to short it somehow and start the uncontrollable reaction there is no way I was going to be picking it up and throwing it overboard.
Oh well there's already lithium on the yacht so what the hell.
I'll hazard a guess that the bolts sheared because of dissimilar metal corrosion - mild steel in an alloy casing? No amount of flushing would have stopped this. When you get back from your trip, try the easy-outs (which are not that easy) and tool up with a threading kit, which will be useful for other jobs. If the bolts are hard-ish mild steel in soft-ish alloy, you might need a professional machine shop to get them out. When replacing them, I suggest using lots of Tefgel. You could even use nylon washers, in addition to the Tefgel, to help insulate the bolt from the casing (others on this forum might have an opinion about using nylon washers as electrolytic insulation).
Incidentally, I had to go through this rigmarole when removing the hex bolts from the roof of my Ford Territory to mount roof-racks They were stainless steel in a mild steel casing. Had to phone someone in to do it because the easy-outs could not get out the last of the bolts. I think the rain on the roof got to the left-hand set of bolts, and that is what made them much harder to remove that the right-hand side. Left and right because of how you park the car on the kerb - the left is always lower.
There are plenty of options for electric motors for tenders. Hope you get yours sorted in time. Lithium batteries have been around for so long, I wonder if the fire-risk should now be consigned to the urban-myth basket. If you have a mobile phone, you carry one around in your pocket all the time. Please let us know how you go.
Ive taken the leap and put 2 x 150AH Lithium batteries on Martzcraft 35. So far, 6 months later they are much better than the old SLAs I had. Charge quicker. Last longer. And much lighter. But there is a fire risk now that wasn't there before. A year ago I dropped my mobile phone on tiled floor. A short time later it started hissing. (No kidding). I threw it into our bathroom and it burst into ferocious flame. I think the big problem is a lithium fire is hard to start but once it does you cant stop it. Firies agree.
www.theguardian.com/australia-news/2023/aug/27/firefighters-fear-being-overwhelmed-by-rise-in-battery-fires-after-fatal-sydney-blaze
Select to expand quoteAchernar said..
I'll hazard a guess that the bolts sheared because of dissimilar metal corrosion - mild steel in an alloy casing? No amount of flushing would have stopped this. When you get back from your trip, try the easy-outs (which are not that easy) and tool up with a threading kit, which will be useful for other jobs. If the bolts are hard-ish mild steel in soft-ish alloy, you might need a professional machine shop to get them out. When replacing them, I suggest using lots of Tefgel. You could even use nylon washers, in addition to the Tefgel, to help insulate the bolt from the casing (others on this forum might have an opinion about using nylon washers as electrolytic insulation).
Incidentally, I had to go through this rigmarole when removing the hex bolts from the roof of my Ford Territory to mount roof-racks They were stainless steel in a mild steel casing. Had to phone someone in to do it because the easy-outs could not get out the last of the bolts. I think the rain on the roof got to the left-hand set of bolts, and that is what made them much harder to remove that the right-hand side. Left and right because of how you park the car on the kerb - the left is always lower.
There are plenty of options for electric motors for tenders. Hope you get yours sorted in time. Lithium batteries have been around for so long, I wonder if the fire-risk should now be consigned to the urban-myth basket. If you have a mobile phone, you carry one around in your pocket all the time. Please let us know how you go.
Thank you yes I know it is going to be a bastard of a job and not one I have time to do while I am prepping to go away imminently.
Select to expand quoteTrek said..
Ive taken the leap and put 2 x 150AH Lithium batteries on Martzcraft 35. So far, 6 months later they are much better than the old SLAs I had. Charge quicker. Last longer. And much lighter. But there is a fire risk now that wasn't there before. A year ago I dropped my mobile phone on tiled floor. A short time later it started hissing. (No kidding). I threw it into our bathroom and it burst into ferocious flame. I think the big problem is a lithium fire is hard to start but once it does you cant stop it. Firies agree.
www.theguardian.com/australia-news/2023/aug/27/firefighters-fear-being-overwhelmed-by-rise-in-battery-fires-after-fatal-sydney-blaze
Thanks.Yes the boat already has a 120 amp hour lithium and the sailing club hasn't rung me to tell me has burnt down yet. I'll be interested to see how much charge it has left after three months on its own. I wasn't game to leave anything hooked up to it.
From work l can see St Kilda where my boat is moored. After reading the above l did look up to see if l could see smoke from my boat. Luckily nothing.
Lithium does runaway..although it's usually the polymer batteries not the Lifepo4 type that ate more common on boats. Scooters and cars seem the main culprits.
I've been using a 44lb thrust watersnake and 49AH LiPO4 battery for a couple of years on my 2.4mtr air deck inflatable. pro's: quiet and relaxing, easier to load and attach as motor is lighter, battery lasts amazingly well. no fuel storage issues and I can charge battery at home or via boat solar
cons: 36 inch shaft is overkill for an inflatable - steering head is high if I'm running in shallow water. Leisurely (slow) it really only gets the tender to 60% the speed of a 3hp OBM. Main concern is that if motor is running at top speed, the watersnake is draining 44amps and my battery says max continuous drain is 40 amps. However I've run it at top speed for 10 minutes regularly with no dramas.
still glad I bought it. Great for poking around up tidal rivers etc
Had 18lb Watersnake with 20amp lithium on 8ft walker bay - just better than rowing,but no fuel/weight to worry about .
On 25ft Contessa have 54lb/24in Watersnake (11kg )with 100 amp gel battery,being charged by 40amp solar panel . Only for getting off mooring,out into clear - about 200m . Can get 4km+ in still conditions,but not for bar crossing,but should run for a couple of hours on lower setting = could get us home if wind dies ?
Neighbour has one set up for bow trolling on 14ft tinny - creeps around the channel all day .
Have 6hp 2 stroke Johnson for when it gets serious,but weighs 38kg + fuel
Mason
Thank you so much for that practical information guys. I am about to pick up a 54 pound thrust water snake with a 42 inch shaft which I know will be way too long for the air Deck inflatable dingy but it's all I can source on short notice. I was hoping I might be able to cut down the shaft later.
Do you guys think that is feasible?
It's a good story to read for all outboard owners. Pull your legs off every 2 years and replace the impeller and Tefgel or lanolin paste everything. I got a lovely 8 HP Evinrude that had hardly ever been used but I could not get the drive Shaft out of the spline. Ended up wrecking it. So open up your outboards or they may stay shut tight
Select to expand quotejulesmoto said..
Thank you so much for that practical information guys. I am about to pick up a 54 pound thrust water snake with a 42 inch shaft which I know will be way too long for the air Deck inflatable dingy but it's all I can source on short notice. I was hoping I might be able to cut down the shaft later.
Do you guys think that is feasible?
I've wondered about shortening the shaft as well. Can't see why it couldn't be shortened from the upper end. depends on how well it's sealed. Let me know how you go!
Select to expand quoteBushdog said..julesmoto said..
Thank you so much for that practical information guys. I am about to pick up a 54 pound thrust water snake with a 42 inch shaft which I know will be way too long for the air Deck inflatable dingy but it's all I can source on short notice. I was hoping I might be able to cut down the shaft later.
Do you guys think that is feasible?
I've wondered about shortening the shaft as well. Can't see why it couldn't be shortened from the upper end. depends on how well it's sealed. Let me know how you go!
There is a guy on YouTube who does it with a different brand and a fancy cutting tool so as to not cut the wires inside.
Select to expand quotejulesmoto said..
Thank you so much for that practical information guys. I am about to pick up a 54 pound thrust water snake with a 42 inch shaft which I know will be way too long for the air Deck inflatable dingy but it's all I can source on short notice. I was hoping I might be able to cut down the shaft later.
Do you guys think that is feasible?
Just another life experience story to scare you enough so you can't sleep,
I had the same electric ( iirc ) 7-8 yrs ago that l used on my inflatable to get out to my fb cruiser.
12 volt spare car battery...might have been too many herbs but the crappy wiring would start smoking well before l got to the boat.
I hope they have put better cables on them now.
The Watersnake T24 controller is mostly empty and easy to remove. It has just one bolt holding it to the stainless tube, but you need to take it apart to release the wires. Use a pipe cutter to shorten the tube and then reassemble the controller.
Here's a good deal for a 40lb trolling motor. $179 + $15 delivery. Only 10 left and the sale is sure to end for the last few.
idyllicoutdoors.com.au/product/electric-trolling-transom-motor-68631/
So cutting down the shaft on the water snake looks straight forward and will complete this afternoon after undoing one bolt and about seven self tappers and removing four spade connectors.
The top of the shortened shaft will need to be drilled to accept the retaining bolt but that too is simple. Just messing with the dinghy to get the final length measurement. Some have suggested that it would be useful for maneuvering the Clubman in that emergency with no wind or tide but of course once it's cut down that probably won't work and there really isn't anyway to mount it.
Interestingly I put a tape over the Clubman and including Hull curvature it appears to be about 27 foot six inches not including the rudder so perhaps the eight refers to a water line measurement. It also draws 1.8 so not really that small a boat. No wonder it goes like a bat out of hell with its 11 meter mast.
Still waiting on the damn battery to be delivered to the sailing club for the outboard but I'm amusing myself by replacing the blocks on the keel lifting mechanism to one's with 8mm pins rather than six.
Not particularly impressed that the water snake manual says to install a fuse by cutting the supplied leads. I have done so but what a cheap ass move not to include it.
Ok so the fairly thick walled leg is actually fibreglass. I started cutting it down with a pipe saw thinking it was aluminium. It ended up being too thick for the pipe saw to go right through and also developed longitudinal cracks because of the crushing. Luckily I cut it a little too long on the first approximation so I got a hacksaw in the end and cut off another two inches to get rid of the longitudinal cracks. Unmistakable smell of fiberglass dust.
Looks like you are having fun!! Very informative and good pics. Following with interest, as I would like to go for an electric motor, but have also thought the legs are too long for a rubber ducky. I'm hoping it all works out.
Enjoy your time up there!!
Cheers 
Select to expand quoteBeamReach said..
Looks like you are having fun!! Very informative and good pics. Following with interest, as I would like to go for an electric motor, but have also thought the legs are too long for a rubber ducky. I'm hoping it all works out.
Enjoy your time up there!!
Cheers
Thanks.
The water snakes are available down to a 26 inch shaft and 36 which should be ideal for a dinghy. I could only get the 42 on short notice and have cut about eight inches off it so I will see how that goes. Buggered if I know where they measure from and to tho as I couldn't come up with any measurement that was 42 whether I went from the center of the prop shaft or down to the skeg end
Kind of twiddling my thumbs waiting for my outboard battery to arrive as FNQ delivery times are quite considerable:-(.
Got the coach house false roof off to expose the support for the keel lifting blocks which I am replacing and my little one is enjoying the lagoon pool as the temperature is about 30 degrees until it plummeted down to a chilly 24 this afternoon.
Thanks for the update. I didn't realise that your trolling motor was 42", understand now why you needed to reduce the length.
It will be good to see how it performs overall, once you receive the battery.
The scenery looks nery nice, another World up there!!
The Clubman TS is a good size. All the best with replacing the blocks on your lifting keel.
Enjoy your stay..
Cheers
