Mariner 2-stroke starting problem

[bigman1]

Originally Posted by mikedefieslife

The 3.3hp is the same as the 2.5 just with a different carb slider and slightly different final drive ratio. I have the 2.5 that I swapped the slider for a shorter one to effectively turn it into a 3.3

On cold days it starts well, left sitting in the sun in 30 degrees (I'm in Greece too), it starts well. Slightly over fuel the carb, and it's a bitch to start.

I should add, always bring it to a stop by letting the carb run out of fuel and not using the emergency stop. When I use the latter I sometimes have to pull it a few times with the fuel off to drain the carb, then start it normally.

Mike is right always shutdown all 2 stroke engines by running carb dry,then you dont get a build up of oil,every time you try to start.Most 2 stroke outboard starting problems are with the carb.Freshen the petrol and oil mix and try again.

[Keny]

It could be your fuel causing the problem. I have a 15hp Mariner of the same vintage and a few years back I was having a similar problem. Some times it would start 1st pull and other times you could not start it for the love of money. It turns out that my son had recently filled the fuel tank and used a fuel that had a 10% ethanol mix. Apparently ethanol evaporates at a lower temperature than petrol (or gas as you may call it) and causes air locks in the fuel lines. I refilled the tank with ethanol free fuel and the problem stopped. The warmer afternoon temperatures you are experiencing could be causing this to happen.

[mikedefieslife]

Originally Posted by Keny

It could be your fuel causing the problem. I have a 15hp Mariner of the same vintage and a few years back I was having a similar problem. Some times it would start 1st pull and other times you could not start it for the love of money. It turns out that my son had recently filled the fuel tank and used a fuel that had a 10% ethanol mix. Apparently ethanol evaporates at a lower temperature than petrol (or gas as you may call it) and causes air locks in the fuel lines. I refilled the tank with ethanol free fuel and the problem stopped. The warmer afternoon temperatures you are experiencing could be causing this to happen.

These engines are designed to run on 10% ethanol.

[Keny]

Originally Posted by mikedefieslife

These engines are designed to run on 10% ethanol.

I'd be very surprised if this was the case. Apart from ethanol being linked to corrosion in small engines there is also the issue of the carburettor jets needing adjusting to run properly on ethanol. Ethanol also destroys O rings and gaskets. Every mechanic I know recommends not to use ethanol fuel in two stroke motors and that includes lawn mowers, edge trimmers, chainsaws and the like.
Also remember the OPs motor is 20 years old and hence was manufactured before ethanol became a common fuel additive, so I doubt it was ever designed to run on ethanol.
Google it and you'll find hundreds of reasons not to put ethanol fuel into your 2 stroke motor.

[mikedefieslife]

Originally Posted by Keny

I'd be very surprised if this was the case. Apart from ethanol being linked to corrosion in small engines there is also the issue of the carburettor jets needing adjusting to run properly on ethanol. Ethanol also destroys O rings and gaskets. Every mechanic I know recommends not to use ethanol fuel in two stroke motors and that includes lawn mowers, edge trimmers, chainsaws and the like.
Also remember the OPs motor is 20 years old and hence was manufactured before ethanol became a common fuel additive, so I doubt it was ever designed to run on ethanol.
Google it and you'll find hundreds of reasons not to put ethanol fuel into your 2 stroke motor.

I have the owners manual for the 2.5-3.3 it does state "The fuel system components on your Mercury Marine engine will withstand up to 10% alcohol content in the gasoline."

I'm in Greece so in the same weather as the OP most likely buying fuel from the same fuel suppliers, I'm not having a problem so far (I've probably jinxed it now)

[Paramotorgreg]

Originally Posted by mikedefieslife

If you are in or around Nidri/Vliho I don't mind giving you hand with the carb. Of course you might be somewhere else entirely though.

Hi Mike, thank you very much for your kind offer. How long will you be in Nidri for? We are currently in Corfu and will be making our way down to Lefkas in a few days. If you are planning to stay in Nidri for a while I would be very grateful for your assistance!

[mikedefieslife]

I can't say exactly, possibly another week.

I took my carb apart over winter, it really is a simple process. So happy to walk through it if I'm still here.

Failing that there is Ionion Boat Assistance here who will be able to help and Nidri Marine.