Mercury 110 9.8hp no spark

[Mastercraft]

Hi,
I’m working on a old Mercury 9.8hp that has no spark. I will get the serial number tomorrow it’s one of the older ones with points. I think the stator is my problem but I’m not sure. I follow the testing procedure that I found on outboardignitionsystems.com. It also has a stator made by CDI electronics on it.

1. Use a jumper wire and short the orange (Salmon) wire to ground. If the engine starts, use the choke to kill it and replace the kill switch.
2. Disconnect the points wires from the ignition coils and connect a jumper wire to the negative side of the coils. Crank the engine and carefully tap the jumper to engine ground, if the coil fires – check the points and points wires. If it fails to fire, inspect the ignition coil. You should have either a red, orange or green coil with a ground wire coming out of the backside of the coil. This braided ground wire MUST be connected to engine ground. You cannot use a black or blue ignition coil.

Are the above steps a good way for testing the ignition system on these motors?
I’m have a hard time finding any Specifications on these old Mercurys. I’m used to looking in a service manual if need be and using a Multi meter or DVA to test the components.

[fleetwin]

I don’t have any Merc experience, but the first test seems backwards…I’m guessing the stop lead is the salmon lead, seems like it should be isolated from ground for this test…
I’m sure a Merc guy will chime in and clarify this…

[Mastercraft]

I’ll have to try isolating the stop lead to see what happens unless anyone has any other ideas. The serial number for the engine is 3086010.

[crosbyman]

mdl #?? year ….???

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[dave-bernard]

your motor is a 1971. big (white problem with them is the insolater on the points.(white)
points will look real bad BUT that is how they are supposed to be.

• This reply was modified 4 years, 1 month ago by dave-bernard.

[crosbyman]

see diag …

starter is for Merc 20hp

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[fleetwin]

OK, so this system is somewhat similar to OMC’s “low tension” ignition system? The electrical theory escapes me though….What does the salmon lead do? Looks like it is kind of connected to the key switch/stop button….

[Mastercraft]

Interesting so the testing procedure I found seems to be the correct way to test the system?

How would I test the isolator?

[crosbyman]

test your kill button by itself…with an ohmmeter is it either a normally open NO or normally closed NC contact when you don’t pust it

when you push it it will alternate from it’s dormant condition to the other one NC becomes NO or NO becomes NC as in INFINITE and or as 0 ohms (short)

whichever circuitry you have the test will prove it is working ok

the kill button will have one of it’s two engine side wires grounded to contribute to what ever your killing function needs to be OPEN or Closed to kill the ignition when you push it

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• This reply was modified 4 years, 1 month ago by crosbyman.
• This reply was modified 4 years, 1 month ago by crosbyman.

[seakaye12]

Have you done the ohms test supplied by Mercury?
Have a look at the attached spec sheet.

• This reply was modified 4 years, 1 month ago by seakaye12.
• This reply was modified 4 years, 1 month ago by seakaye12.
• This reply was modified 4 years, 1 month ago by seakaye12.

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