Thursday, May 17, 2018

New Engine

New Engine for our dinghy

We made the decision to upgrade the engine for our dinghy. Currently we have a Suzuki 2.5HP 4 Stroke Outboard which is fine, but we're concerned that the strong currents in the Bahamas will be an issue with just 2.5hp.

Our dink - Mercury 2400 has a max engine capacity of 4hp. So we have just purchased a new Mercury 4HP Short Shaft (15") from West Marine. Their price was close to what we could find online but with the 4% back in West Marine Bucks, and their price guarantee, I'm happy that we made the best choice.

 The guys from the Pompano West Marine Store loaded the new Engine, in it's box, onto our F150 pickup.

They wrapped it in poly garbage bags as it was threatening to rain.

The engine weighs about 57lbs 26kg. So it's easily lifted single handed, but the box makes it a bit of a task. 





We drove down to the dock and turned the boat around. Eximius is normally docked facing East, but the dink's outboard is on the Mount attached to the Port Side aft rails and I didn't fancy carrying the engine across the boat and then trying to hang it on the lifting sling while it's over water.

The wind was from the South East, which meant that turning the boat was a breeze (no pun intended 😏) We ran a line from the Port side bow aft and around the stern then to the dock. A second line from the mid ships cleat port side, aft and around the stern to the dock. I released the stern lines and then the bow lines. The boat easily floated around to port and I was able to control the turn using the two lines from the dock.

Once the boat was secured port side to. I made up the new engine lifting tackle. The tackle for the 2.5hp engine was a simple 1:1 single block and tackle, but I figured a 3:1 advantage would help lift the heavier 4hp engine. Now we have a single block attached to the underside of the Radar mounting plate and a double block as the moving part. There are 3 lines on the moving block.

With the new lifting tackle setup, I took the Merc out of the box and carried it down to the dock. Peggy sat on the dock wall while I tied a temporary lifting harness to the engine. With that harness attached to the moving lifting block, Peggy was able to take up the slack as I move the engine over the gap between the boat and the dock. 

The good news is that the mounting bracket on the new engine fits the existing storage bracket on the boat, no need for any adjustments.

We brought the new engine home so that we could commission it in the garage and run it in the back yard.

Commissioning the engine involves: Add Engine Oil (it's shipped empty), checking oil levels, fuel up the engine and then running it for a few minutes before checking the engine oil level again.

To do that it has to be in the upright position, so I need an Engine Stand -

Using my HF Dolly, but it needed some extra stability as the weight of the engine tends to tip the dolly forwards.

I took a scrap of 3/4" Plywood, cut it in two diagonally, then cut a slit close to the vertical end using the plunge method on my table saw.

The supports fit like a glove and really make a big difference, no fear of the dolly falling forward when the engine is mounted and the supports can be pulled off easily. No screws required.



The horizontal bar of the dolly is straight 1" steel tubing, not suitable for securing the engine. I padded it out with more offcuts of the 3/4" ply, I should really cut off the excess srew length with my rotary cut off tool.

The padding can handle the torque tendency for the engine to roll forwards, the padding is held in place with a half dozen long screws and nut's n bolts.

With the engine mounted on the dolly, there's plenty of room to place a tall drum bucket around the prop, high enough to submerge the water intake. If we had the Long shaft engine, the bucket would not need to be raised up to submerge the prop, but ours is the short shaft (15") so I place a couple of stone slabs under the bucket. That also helps keep the dolly stationary when flushing / running the engine.



Most of the time, the engine will be secured to the outboard engine mount on the Port side aft of Eximius, time for some shade.

I watched the video on Sailrite several times and figured out how to adapt their concept to our engine.

Our engine seems to have the knuckle joint for the tiller slightly further aft than on the model engine that they covered. So the cut out for the knuckle was not in the corner. It worked out really well.

There are a lot of appendages on the front and sides of the engine, but the cover fits well and is very secure.

The tiller cover is separate but I don't expect to ever run the engine with the main cover in place.

Note that this dolly has a removable handle, this is great as it allows the engine to rotate on the dolly for servicing.





I reused some Sunbrella from our old Sail Cover (replaced when we got new sails in 2016 and a Cradle Cover) so the cost of the cover was minimal. It would have cost about $25 for a yard of Sunbrella, I used about 5' of cordage and one bobbin of thread. I did not use basting tape.

Tools to upgrade the dolly: Table saw (could have used a circular saw), Portable Drill/Driver, Socket, Builders square, Ruler, Marking pens.

Tools used to make the cover: Hot knife to cut the sunbrella and cordage, Sailrite LZ-1 sewing machine, 8 plastic clamps (harbor freight), Marking chalk, Tape measure, 36" wooden rule, 48" T-Square (drywall square), Thread snips.

I find myself doing more and more canvas projects, Sailrite has been great in supplying materials for the stuff I've made as well as stock that I have purchased in anticipation of more projects. This is really the first project that I have re-used old Sunbrella, it was in pretty good shape, but it needs some cleaning - The engine cover is going for a bath in OxyClean and will then get a coat of water proofing.