Starting 2-Stroke Outboard

[MannY]

Hi Guys,

I'm new to boating and trying to get my head around 2-stroke engines. I bought an old Johnson 10hp and had it serviced(it sat around for a couple of months as I needed to completed my boat lic to use it)... now time to start it.

Firstly I had the wrong fuel line connector, so I bought a new tank with the correct fuel line.

Now, I struggle to start it. Once it's started she runs good. The problem occurs when I stop and then start it or do a cold start.. From I have been told this is how to start it, please correct me if I'm doing something wrong...

1 - Make sure I have fresh premium\ unleaded petrol.. 50:1 mix

2- Open fuel valve

3- Prime the line

4 - Pull the choke

5 - Turn throttle to start

6 - Pull until she starts, trying to avoid flooding.

Sparks look ok, I need some ideas on how to diagnose it.. please help

[bessell1955]

Too much choke, causing flooding?

[antonywardle]

do you do the same procedure when the engine is warm?

I'd guess not using the choke when warm is a good idea.

cheers

[MannY]

I don't use the choke when its warmed up.

Cheers

[Fab1]

Hi Guys,

I'm new to boating and trying to get my head around 2-stroke engines. I bought an old Johnson 10hp and had it serviced(it sat around for a couple of months as I needed to completed my boat lic to use it)... now time to start it.

Firstly I had the wrong fuel line connector, so I bought a new tank with the correct fuel line.

Now, I struggle to start it. Once it's started she runs good. The problem occurs when I stop and then start it or do a cold start.. From I have been told this is how to start it, please correct me if I'm doing something wrong...

1 - Make sure I have fresh premium\ unleaded petrol.. 50:1 mix

2- Open fuel valve

3- Prime the line

4 - Pull the choke

5 - Turn throttle to start

6 - Pull until she starts, trying to avoid flooding.

Sparks look ok, I need some ideas on how to diagnose it.. please help

You mention since changing out the tank and fuel line you now struggle to start your engine,is this correct?

If you've run the engine and it's still warm when restarting you don't need the choke.

From a cold start yes use the choke with a slight throttle opening.

These are the things I'd check:

Make sure fuses and all wiring are in good condition.

Make sure the vent in the tank is in the open position.

Make sure fuel line is connected/pushed in all the way in both the tank and engine without sucking air in.

When priming fuel bulb it should get hard/firm.

Check the fuel filter bowl has fuel in it.

Check the choke is engaging/disengaging correctly without sticking either open/closed.

Remove the spark plugs and check their condition/gap,rectify if necessary.

With a plug removed connect a HT lead to the plug and ground to engine.

Pull on starter rope to confirm your getting a bright blue strong spark at the electrodes.(If its yellow or none existent you have a weak ignition system or perhaps a faulty wire somewhere)

While the plugs are removed do a Compression test on the cylinders if possible there should be roughly no more than 7-10% variance between the two.

There's no need to use premium unleaded,just regular unleaded is fine,stay away from E10.

If your not comfortable doing these things/checks perhaps its time to go and see a reliable trustworthy Mechanic to get sorted.

Cheers.

[daniel944]

If your engine runs fine once you get it going, I doubt theres anything wrong with the engine. I can suggest varying the throttle opening and the choke setting. Don't assume full choke is required for a cold start, this may just flood the motor. Also I find that if you are cold starting and she fires but dosnt run, open the choke right up (disengage it) and try again.

When its warm most engines will start fine with closed throttle and open choke

[MannY]

Thanking you.. will try that