mikey

Sexy Orange Outboard Sans Sparks

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Not exactly car - but it is old school! I've got a 1984 Johnson V4 2-stroke outboard with no sparks anywhere.

IMG_20180930_102858.jpg


If I hook up a timing light it gets triggered okay.

I've followed the tests in the manual and these all checked out:

  • Jumpered the Powerpack connectors excluding the kill switch
  • Sensor Coil Resistance
  • Sensor Coil Short
  • Charge Coil Resistance
  • Charge Coil Short 

These next tests are supposed to be done by measuring peak voltage which my meter doesn't have so I measured AC instead.

  • Charge Coil output should be 150V - I got 95VAC
  • Sensor Coil output should be 3V - I got 0.1VAC
  • Power Pack output should be 170V - I got 84VAC

I'm assuming that if I could measure peak voltage these numbers would be roughly correct. I'm gonna build a DVA to test them properly today.

Anyone else got any ideas? 

It could be that all four coils have died at the same time, but that sounds unlikely. 

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Multimeters are slow at responding. You won't get a good reading from one for this sort of situation, you'd need something like an oscilloscope.

 

If your timing light is being triggered that would indicate you have spark? What condition are the plugs?

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18 minutes ago, ajg193 said:

Multimeters are slow at responding. You won't get a good reading from one for this sort of situation, you'd need something like an oscilloscope.

 

That's what the DVA is for - it will hold the peak voltage long enough to measure it on the meter.

 

18 minutes ago, ajg193 said:

If your timing light is being triggered that would indicate you have spark? What condition are the plugs?

 

Yeah, that's what I was thinking. I've tested the test-plug on my car and get a yellow spark across it. I would've thought I should get a bright blue spark on my car - so maybe the test plug isn't so great... 

I should grab a new plug for testing. The plugs in the engine are around 4 years old and look a bit manky. Could also be they're all wet from trying to start with old fuel...

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Yeah, I think it maybe as simple as this. I mixed some new fuel in with it, but this could be my fail. 

I'll get a new plug and check the spark. If I have spark put new fuel in it. 

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20 hours ago, ajg193 said:

Old 2 stroke fuel will just give you headaches

So yeah. It was just manky old fuel.

Lesson learnt there; drain you crabs and use fresh fuel if it's been sitting over winter. Also, testing for spark with dirty plugs can lead to false-positives.

Thank for your help @aja540i :flower:

IMG_20180930_153850.jpg

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I usually get away with just draining the carb bowls and topping up the tank with higher octane than I normally would. Have yet to drain the entire tank

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3 hours ago, mikey said:

So yeah. It was just manky old fuel.

Lesson learnt there; drain you crabs and use fresh fuel if it's been sitting over winter. Also, testing for spark with dirty plugs can lead to false-positives.

Thank for your help @aja540i :flower:

IMG_20180930_153850.jpg

I hear that outboard mechanics make the most profit off of "fixing" engines when the owner just had old fuel.

 

Looks like it was a good day to get out there

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25 minutes ago, ajg193 said:

I hear that outboard mechanics make the most profit off of "fixing" engines when the owner just had old fuel

Mostly because I have old guys argue with me that the fuel is "fresh enough" and insist there's something wrong with the motor that needs fixing. Trust me, old fuel is a fucking headache on outboard motors.

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51 minutes ago, igor said:

Is that cos modern lead free shit?

Seems to have gotten worse in the last few years for sure, but the official fuel shelf life is 3 months according to BP. But then chuck that in a plastic tank in the sun with an open vent and you can halve it again.

Best thing for your outboard is to run fresh and preferably 95 octane fuel, and quality oil (read: Not Valvoline).

Glad to see you got it ripping, sorry I didn't see the post before hand.

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17 minutes ago, punkoutnz said:

Seems to have gotten worse in the last few years for sure, but the official fuel shelf life is 3 months according to BP. But then chuck that in a plastic tank in the sun with an open vent and you can halve it again.

Best thing for your outboard is to run fresh and preferably 95 octane fuel, and quality oil (read: Not Valvoline).

Glad to see you got it ripping, sorry I didn't see the post before hand.

What's wrong with Valvoline oil? I run the xd50 but my grandfather ran Valvoline from the 70s on

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6 minutes ago, 00quattro00 said:

What's wrong with Valvoline oil? I run the xd50 but my grandfather ran Valvoline from the 70s on

We used to recommend it back in the day. Now it blows engines up. Dunno what they changed but it's causing us (and most other dealerships) a lot of problems at the moment.

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On 1/10/2018 at 13:22, 00quattro00 said:

What's wrong with Valvoline oil? I run the xd50 but my grandfather ran Valvoline from the 70s on

I was going to ask this too.

Ever since I was a small boy and we got our first boat valvoline was all we used.  I run it in my 50cc too. Should I dump it out and buy something else???

Edit, of my scooter

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On 16/10/2018 at 15:35, RUNAMUCK said:

I was going to ask this too.

Ever since I was a small boy and we got our first boat valvoline was all we used.  I run it in my 50cc too. Should I dump it out and buy something else???

Edit, of my scooter

We've been telling people to dump it, yeah. Too much of a coincidence to have so many blown engines all running the same oil. Maybe if it's some really old stuff you've had lying around it'll be good (we used to recommend it to customers), but anything that's been purchased in the last 18 months I'd say ditch it.

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