Diagnostic tips and tricks whilst on the water

[2x2smoke]

When these boats develop problems, many people have difficulty dealing with and fixing them out on the water. Limp back to the dock with long faces and head home to try to figure out what's wrong. Many things can be done on the water to help diagnose what the problem is and some of these problems are easily dealt with to save the day.

Before you hit the water:
-Read the owner's manual so you know how a normal boat is supposed to act ie neutral switch, fuel valves, coolant flow, telltale, mpem beeps, etc
-Bring a proper set of tools including things to adjust and check the fuel mixture screws, rave valves, spark plugs and fuses. Infrared temperature gun, grease gun, multimeter and maybe even a compression tester
-Bring spare parts especially fuses and sparkplugs. Bring your spare DESS key to swap out if necessary. Keep a spare carbon ring assembly and an extra trailer hub in your truck. Carbon seal replacement should take about 20 minutes on shore.

Example whilst on the water:
Engine bogging or sluggish? Gently pull the choke lever. Engine dies, its probably not a too-lean carburetor problem. Engine improves, its probably running too lean.

List your secret tricks or techniques employed when the boat tries to ruin your day.

 

[Helena]

Thank you!!

 

[2x2smoke]

Here's one from Saturday. Boat running great all morning then stop for lunch. Large tube tied to back of boat to cruise around between play sessions. Boat develops the dreaded "won't rev past 5000 rpm" issue. One engine and then the next 10 minutes later. Uh Oh. Stop to drop anchor, swim and try something....

-Pull out the old spark plugs and replace. This is pretty easy on the water and now you can see if there is an obvious mixture problem or at least see if new plugs help the issue. In my case the pto plugs were darker than the magneto plugs. Hmmm.

Dry off and start back towards the marina. New plugs didn't fix the problem.
-Pulling the choke kills the engine instantly.
-Feathering the throttle doesn't help. My boat has accelerator pumps on the carbs so feathering the throttle richens up the mixture so this is probably not a lack of gas issue.

Next trick, try to add air to the engine compartment in case the engines are starving for oxygen.
-Turn on the bilge fan (works for some but not for me). The fan is actually sucking air out of the bilge so it could make things better or worse. There is a tube tied to the back so I can't really:
-open the engine hatch to try that ventilation trick

What I can do from my driver's seat to add ventilation is :
-pull out the hull the nearest cup holder insert. I can feel the air being sucked into the bilge around my hand. The engines are definitely pulling fresh air through the cup holder hole. After a couple of minutes, one engine starts to climb up to 7000 rpm. The second one followed suit shortly after. Twin engines sang all the way back to the dock.

I hindsight, I think the tube tied to the swim platform was choking the air intakes for the bilge back there. The engines were probably starved for oxygen. I had to try 6 on the water tricks to finally diagnose and fix the issue but the day wan't spoiled and I learned a new one about not blocking the intake vents at the back of the boat.

Pulling a cup holder, or speaker or opening the ski locker will all add ventilation to the bilge if you suspect your engines are starved due to an exhaust leak or blocked intakes. Just be mindful that exhaust gasses could now enter the cockpit area so diagnose wisely.