Water in the fuel tank of my Zodiac dinghy with Yamaha 2001 50 HP

Does it have spark when it cuts off?

first bit of advice
do not use e-mix fuels in outboard engines
WHY
because ethanol separates from the fuel if not used continuously so letting it stand between outings is not good
secondly ethanol is hygroscopic which means that it absorbs moisture from the air that is going in via the tank vent and that results in corroded aluminium parts and rusted fuel tanks and outboards operate in a very moisture laden environment
now for the problem
being a late model engine , it should be a 4 stroke and like any 4 stroke engine , check the timing belt/chain, crank/cam position sensors , ignition module
it is important to check all harness connections as salt water rapidly causes corrosion in electrical connections and components
have the service agent do a scan for fault codes remember this
Suzuki out board 2 stroke motors were used in the early suzuki 4x4 cars and modern 4 stroke engines are simply car engines on end

water in the engine crank case oil --major seal or corrosion problem in the motor
water in the leg gear box --
pump seal on the drive shaft

firstly from the photo it looks like it is a four stroke motor in which case you do not mix the fuel with oil
it is a two stroke engine and needs oil mixed in the fuel , it is not done in the fuel tank but in a container ( 5 ltr-1 gallon) before hand
mixing in the tank will create problems from not enough oil to excessive oil as the motor is running
only use 2 stroke oil --not engine oil
of in doubt take it to a mower shop and get advice on what should be done before you start it.

Runs with the choke on..!??.... the choke cuts off the air supply or in some cases adds extra fuel.. With respect to both, ..they accomplish one thing.. the richen up the fuel mixture..SO with that..,, your engine is starving for fuel ... Its usually the low speed jets are clogged...there are numerous SMALL air and fuel passages that are sometimes hard to clean properly.. Take the carbs to a qualified professional and let him clean and set them.. (if you removed any of the screws that affect the jetting/air/fuel mixture/idle circuit,, they MUST be set back to the factory settings)..

Need to hook up YDS diagnostics and check for codes first. Second you need to hook up a fuel pressure gauge on the motor and make sure your keeping steady fuel pressure. Did you check the grommet on top of the high pressure pump for a split in the rubber?

clean your carbs etc !! fit a water fuel seperator inline from tank to stop problems !

2001 Yamaha YZ80 Specifications Engine Engine Type
2-stroke Displacement
83 cc Bore x Stroke
47 mm x 47 mm Compression Ratio
8.2:1 Engine Cooling
Liquid Carburetion Carburetor
26mm Mikuni Transmission Transmission
6 - speed Chassis Wheelbase
49.5 in Ground Clearance
13.7 in Seat Height
33.6 in Fuel Tank Capacity
1.3 gallons Forks Forks
33mm Kayaba Fork Travel
10.8 in Shock Shock(s)
Kayaba Shock Travel
11.1 in Wheels and Tires Front Wheel
17 in Rear Wheel
14 in Brakes
disk/disk Other Information Intended Use
Motocross Color Scheme
Blue Cost when new
$3199

DO NOT mix oil in the gas on your four stroke engine. You will foul the spark plug(s), build up deposits on the valves and head, and make a smokey, smelly mess. A two stroke engine uses the fuel/oil mix to lubricate the engine before being used as fuel. A four stroke engine has a separate lubrication system and does not normally burn any oil. As the name implies, a two stroke engine works in two strokes. The first stroke is downward, where the fuel/oil mix and air are drawn into the cylinder. The momentum from the crankshaft counterbalance or force from the other cylinder(s) drive the piston back up compressing the mix, and the spark plug sparks at or slightly before the top of the stroke. The rapid combustion of the fuel/oil/air mix drives the piston down, which is the power stroke, and then the cycle starts all over again. A four stroke engine has an intake stroke down taking in the fuel/air mix, a compression stroke up, a power stroke down as the fuel/air mix is ignited at or before the top of the stroke, and a exhaust stroke up before starting all over again. A four stroke is much cleaner and more reliable than a two stroke, but it is heavier and has less torque. A two stroke engine is much lighter and has more torque, but takes more maintenance.