Mariner 10 hp conks out after a couple of miles.

Amorer · 20 September 2011, 03:39

Hi there,

I have a 10 hp Mariner Marathon with serial number 0D169844. My problem is the motor stops after a couple of miles running and I lose the ignition sparks. After, say 5 or 6 hours waiting, the sparks are back again and I can continue using the motor. It seems that there's some intermittently working switch that opens when the motor or the electronic component are hot and closes again when everything is cooled down. Can somebody who have experience this give me and advice which component is probably faulty.
Thanks in advance.

BR

amorer

Courageous · 20 September 2011, 06:38

Does it die on both cylinders at the same time? Lose spark on both cylinders? I'd be thinking coils initially.

9D280 · 20 September 2011, 08:15

This may be a red herring, but did some engines not have an overheat switch that cut things if it started to cook itself? (Might be old Yams I'm thinking about - no time at the mo to trawl microfiches)

I assume you are getting cooling flow out the telltale?

Amorer · 21 September 2011, 03:14

Hello Guys,
Both plugs lose the sparks at the same time. I don't think the motor overheats as the temp of the block is just normal and while in operation the cooling water monitor was having a good flow. Have changed the ignition coils and still to no avail. After 6 hours, the sparks were back without me doing anything after changing the coils. Have tested again in the water and same results running perfect in the beginning and later when I reduced the speed it just conks out.

Courageous · 21 September 2011, 06:29

9D could still be on the right trail if indeed there is a cut-out there as it may be faulty. If there is one try bridging it out and see if that helps. The time scale of a couple of miles would bear with that theory as the motor is quite likely to be still warming through. I'm sorry we seem to be fudging around don't we? Do you have a manual for this at all?

Amorer · 21 September 2011, 06:42

Hi Courageous,

I can't find any temperature sensor on the motor to bridge or bypass. The manual I have is the Clymer Mercury/Mariner Manual and still working on it to find any troubleshooting tips.

uncle al · 21 September 2011, 16:16

do a stater test and a switchbox test , check all earths are clean and tight also that the connections on the earth wires are tight on the wires ( all connects should be shiny bright)

Amorer · 21 September 2011, 23:04

Hi Uncle Al,

Can you please give me an idea how to do a stator and switchbox test. I only have a digital multimeter but not fluke.

Thanks in advance.

uncle al · 22 September 2011, 09:58

you can use either a digital (eisier to read) or an anolog multimeter, im sorry i dont have any figure to give you, cos i am now retired and dont have that info to hand anymore but i would have thought that they would be in an after market manual

Amorer · 22 September 2011, 11:08

thanks uncle al, I will try to do my research.

uncle al · 22 September 2011, 17:55

i forgot to mention i used to test for volts NOT resistance so check voltages

ADI · 22 September 2011, 21:24

I used to have one of those engines, they are crap, mines kept breaking down

aquatec · 26 September 2011, 10:52

Do as Uncle Al suggests and check the stator and CDI unit. I assume you have a manual start tiller control engine. You should have a stop switch in the tiller and the emergency lanyard stop switch in the lower cowl. Run the engine as normal and disconnect the two Black/Yellow bullet connectors to the CDI unit from the stop switches. See if the engine runs OK now. Have had problems in the past with shorting of one of the stop switches with older engines. To stop the engine after this test disconnect the fuel and let it run out, pull the primer/choke on or connect the wires back up and stop on the switch.