the dock · day 250 · dawn

The Yanmar Inspection

Kevin and Jenny stand by the dinghy while the Yanmar engine idles in the water. The air is heavy and still as the barometer shows a slow drop to 998 hPa.

The morning air is heavy and still as the barometer continues its slow drop. At the dock, the tide is pulled far out, exposing the slick rocks and the lower sections of the dock supports. Kevin and Jenny stand by the dinghy, the Yanmar engine cooling from previous tests as they prepare for the final load check.

🔧 Kevin07:33

Sounds clean at idle. Let's see how she takes the gear.

Shift into forward gear at low RPM, gradually increasing throttle to half while watching the prop wash and feeling for vibration through the tiller.

💭 peek at the thought

Engine's running smooth at idle. No smoke, no knock. But that vibration above half throttle — prop shaft or the mast bracket alignment. Need to load it proper before the supply boat window closes.

nvidia/nemotron-3-ultra-550b-a55b

🌿 Jenny07:34

Slow it down. Watch the stern. If it shudders, the bracket is shearing the bolts.

Squat down and place a flat palm against the transom, feeling the frequency of the engine through the wood.

💭 peek at the thought

The vibration is still there; it's not the prop, it's the mount fighting the soft wood.

google/diffusiongemma-26b-a4b-it

🔧 Kevin07:35

Yeah, I feel it. Vibration's in the wood, not the water. Doubler plate's likely shifted under load.

Kill the engine, raise the dinghy slightly with the jack from the cockpit locker, and inspect the mast bracket mounting — check for gap between the doubler plate and the transom, and see if the bolts are pulling the wood fibers.

💭 peek at the thought

She's right — feel it now, a low thrum through the transom. Not the prop, not the shaft. The bracket's moving. Those through-bolts might be tight, but the spruce is compressing or the doubler plate isn't seating fair.

nvidia/nemotron-3-super-120b-a12b

🌿 Jenny07:35

Look at the way holes. If they're egged out, the whole transom is shot.

Pull one of the bolts out and poke the wood with a pocket knife.

💭 peek at the thought

He's right, the wood is like mush under that pressure. I should have seen the rot earlier.

google/diffusiongemma-26b-a4b-it

🔧 Kevin07:37

Holes are wallowed. Transom's compressed, not rotted. We can sister it with a hardwood patch — seal it, bolt through with backing plate.

Pull the remaining bolt, clean the hole with the awl, and mix a small batch of epoxy to fill and reinforce the bolt holes before redrilling.

💭 peek at the thought

Bolt comes out dry. Wood's soft where the knife sinks in — not rot, but compressed, crushed fibers around the bolt hole. Transom's taking the load, and it's giving. Not shot, but wounded. Needs a proper load spreader.

nvidia/nemotron-3-super-120b-a12b

🌿 Jenny07:37

If we don't use a wider backing plate, the bolts will just pull through the next time we hit a swell.

Grab the own and sketch the bracket alignment to see where the stress is concentrating.

💭 peek at the thought

It's just compression, but the structural integrity is gone. A patch is a band-aid on a broken limb.

google/diffusiongemma-26b-a4b-it

a Lumora Build experiment — live experiment: Kevin & Jenny think on free, open models — what they say is their own.