Mariner 60 2 stroke 3cyl midrange cutout.

[telecast]

Hi Guys,

I am hoping to get some advice about fixing my outboard.

I got the outboard 6 years ago with the boat.

It has run faultlessly (needed new solenoid ) in that time and all servicing I have done myself.

Yesterday got out for first time this year - went to Loch Sunart and we’re going to make a final plan for the trip once we got to Tobamory as weather was due to change.

We launched at strontian and got Apox 5 miles up the Loch at our usual 20 - 25 Knt cruising speed when the engine sputtered and cut out.

At this point went through the idiot check - yes tank vent open, Tank correctly connected. Bulb hard

Turn key engine starts and ticks over as usual. Open throttle slowly and at just above tickover (5 Knts ? ) gets lumpy and cuts out

We head back to launch site - at 5 knts and start trying to diagnose problem

My gut feeling was that it was rich - if you go as fast as possible before it cuts - and then snap the throttle wide open it complains a bit then takes off - just seems to be midrange that is the problem.

I had thought it could be auto choke - we disconnected this and at first seemed to fix but in the end I believe was a bit of a red herring.

Any thoughts much appreciated.

As with all things with carbs I gues cleaning carbs is first step - I do have filter/ water separator fitted - no water etc showing ????

[A1an]

What’s the fuel pump arrangement on that engine? I had one but can remember.

[telecast]

Hi A1an,

Not quite sure what you mean by arrangement ? - but it looks like fuel pipe comes in - oil pump adds oil goes into pump and onto carbs.

[telecast]

A1an - it so happens this outboard is on the back of a 5M Northcraft

[neil.mccrirrick]

I’d start with blocked main jet. If you can get to the float bowl loosen the drain and see if petrol comes out. If there is hardly any it’s carb off and clean

[telecast]

Originally Posted by neil.mccrirrick

I’d start with blocked main jet. If you can get to the float bowl loosen the drain and see if petrol comes out. If there is hardly any it’s carb off and clean

Hi Neil,

Thanks for reply - I was just surprised that it would run flat out ok ?

Cheers

[Peter_C]

Did you drain the fuel bowls before storage? If not definitely start with cleaning the carbs.

I would have recommended pulling the choke while on the water as it was stumbling to see if it made a difference. Sometimes you can even create max air flow IE: full throttle, then slam a can or such over the carb to free stuck debris. A few tries often works to clear the jet(s). Realistically a temporary fix to get oneself home.

[neil.mccrirrick]

At wot it’s sucking hard and will pull fuel past an obstruction.

[A1an]

Sometimes if the rear diaphragm is fubar on the fuel pump the crankcase can fill with fuel and give the symptoms you describe.

You aren’t a million miles from me, if you want to drop the carbs off with me I can ultrasonic clean them and get them back to you.

[telecast]

Originally Posted by neil.mccrirrick

At wot it’s sucking hard and will pull fuel past an obstruction.

Ahhh ok thank you

[telecast]

Originally Posted by A1an

Sometimes if the rear diaphragm is fubar on the fuel pump the crankcase can fill with fuel and give the symptoms you describe.

You aren’t a million miles from me, if you want to drop the carbs off with me I can ultrasonic clean them and get them back to you.

Hi A1an - ok the fuel pump sounds like it might produce the sort of variability of symptoms I was getting.

The carb cleaning is a very kind offer thank you - but decided to order an ultrasonic cleaner last night - should be here today!

Thank you

[telecast]

Thanks for all the help - I feel like I have a plan now.

I have two follow up questions.

1. Will the carbs need balancing after cleaning ? And if so what do I need to do that.

2. Does any one have a recommendation for a parts supplier for that engine.

Thanks

[smallribber]

Be careful ultrasonically cleaning the carbs. You should remove the plastic floats in the carbs because they can split at the seem if left in.

I would just try spraying carb cleaner into the air intakes while it is running a few times before pulling it to bits. This might sort it. These are very good and robust engines. I have 2 of them.

Also if you suspect the fuel pump new ones are quite cheap on eBay

[smallribber]

I don’t think they will need balancing they are quite simple older 2 strokes.

EBay has a lot of parts if not Seamark Nunn can get stuff speak to Martin

[telecast]

Originally Posted by Easedalenovice

Be careful ultrasonically cleaning the carbs. You should remove the plastic floats in the carbs because they can split at the seem if left in.

I would just try spraying carb cleaner into the air intakes while it is running a few times before pulling it to bits. This might sort it. These are very good and robust engines. I have 2 of them.

Also if you suspect the fuel pump new ones are quite cheap on eBay

Thanks for that - will do

[telecast]

Originally Posted by Easedalenovice

I don’t think they will need balancing they are quite simple older 2 strokes.

EBay has a lot of parts if not Seamark Nunn can get stuff speak to Martin

Great - thank you