What's wrong with my Mariner F20M?

[Duggy]

One week before we go on holiday and I thought I'd start the motor up before assembling my kit ready for the off. However, the bloody thing is deader than a Dodo!!

It's a 2006 Mariner 20 four stroke F20M (short shaft/manual start).

Normally when I pulling it to start the red oil light flickers and then as soon as it fires it stays on for 10 seconds (system test) and goes out. However, today when I pull it I get nothing. No red light, and little or no spark.

I've checked the wiring connections, the toggle switch and the tiller stop switch but they all seem OK. I've pulled the Oil Pressure sensor out and cleaned it and I've had the CDi unit off and inspected it.

Everything looks OK, but still nothing.

Anyone any ideas?

Are the symptoms most likely pointing to a broken CDi unit, the Oil Pressure sensor, or something else?

Here's hoping!!

[paintman]

Silly question but you have remembered to put the kill cord on/put the kill switch into the run position?

Can you disconnect the wire to be sure it isn't the kill switch faulty?

[Duggy]

Yes done that - Have also used a multimeter to check the circuit across the kill switches and they're both fine.

[Fenlander]

You really need a dealer workshop manual with an ign/elecs troubleshooting flow chart. With modern designs following this through the steps is better than prodding about.

My Suzuki manual is very good for... check this... what reading is that... now check the next thing... and so on.

[Fenlander]

Here's a wild thought... is it designed so if the oil warning lamp and/or its circuit is faulty then it won't start??

[Duggy]

I don't know for sure. The owners manual says...

LOW OIL PRESSURE WARNING TEST SYSTEM

At engine start-up, the low oil pressure warning light will turn on for 10 seconds as a normal system test.

LOW OIL Pressure

The oil pressure warning light will turn on if the oil pressure drops too low. First, stop the engine and check the oil level etc. etc.

It then goes on to say that if this happens engine speed will be limited to 2100 RPM, however you should not continue to run the engine.

This ^ leads me to think that under normal circumstances the engine should still start and run if there's a lack of oil pressure or a faulty sensor. I have just been out and tried different plugs and have checked the sensor by connecting it to a foot pump and measuring the resistance across it. It seems to be fine, so I am starting to think it is the CD unit that's at fault.

[Duggy]

Originally Posted by Fenlander

You really need a dealer workshop manual with an ign/elecs troubleshooting flow chart. With modern designs following this through the steps is better than prodding about.

My Suzuki manual is very good for... check this... what reading is that... now check the next thing... and so on.

Where would I get a workshop manual for it? I have enough trouble finding parts!!