No spark to plugs

[Shadow91]

Okay, just recently was given a 1986 Seaswirl with a 2.5 OMC I/O in it. Trying to get it to run before taking it out on the water but it appears to have no spark. Taking off the cap/rotor there is spark at the points but nothing getting to the plugs as you turn it over. Not really sure where to start on a system this old, as well as i have never had to mess with a point ignition system.

The model number of my engine is 252FTHRCTR attached to an OMC Sterdrive model # 982740

On top of the no spark concern, what else should i go over on this before i put it in the water? From my understanding it has sat a few years. Would like it to be as reliable as possible.

And just a little background on me, I am a professional automotive technician, so proper tools, diag equipment and i have a general understanding of how engines work. Ive just never messed with marine engines or any ignition systems with points.

Thank you all, and I can provide any additional info if needed.

 

[alldodge]

Okay, just recently was given a 1986 Seaswirl with a 2.5 OMC I/O in it. Trying to get it to run before taking it out on the water but it appears to have no spark. Taking off the cap/rotor there is spark at the points but nothing getting to the plugs as you turn it over. Not really sure where to start on a system this old, as well as i have never had to mess with a point ignition system.

The model number of my engine is 252FTHRCTR attached to an OMC Sterdrive model # 982740

On top of the no spark concern, what else should i go over on this before i put it in the water? From my understanding it has sat a few years. Would like it to be as reliable as possible.

And just a little background on me, I am a professional automotive technician, so proper tools, diag equipment and i have a general understanding of how engines work. Ive just never messed with marine engines or any ignition systems with points.

Thank you all, and I can provide any additional info if needed.

Howdy, and man do I feel old Guess they no longer teach points in auto schools anymore

Get a new set of points and a condenser and install. Loosen the distributor clamp bolt and rotate it so one of the distributor cam lobes are holding the points open. Use a 0.022 so when the motor is running you get a dwell angle of 28 to 34 degrees.

They still make dwell meters, and most time called tach and dwell
Plugs MR43T
Gap 0.035
Firing order 1-3-4-2
Idle in gear RPM 650-700
Timing 8 BTDC
Compression 140 PSI

The coil will have an external ballast resistor or wire. When the engine is cranking, there should be a full 12V on the + side of the coil. When key is in RUN position it should have around 9V. Here is the points ignition setup for a car, boat does not have a vacuum advance

 

[Shadow91]

Okay, so finally got around to ordering a tune up kit (cap, rotor, points, condenser) and a new coil. But now i have no friggin starter signal. I get nothing from the key while trying to turn it over. I can jump 12v to the starter solenoid and the starter turns just fine, and it will now fire if i use starting fluid but im not getting fuel. Any reason why it would not be trying to energize the fuel pump and send a starter signal? Im thinking either bad ignition or some sort of neutral safety system...

 

[alldodge]

There is an assist relay (Merc calls them a slave solenoid) which when the key goes to start, it energizes the relay. The small relay transfers power to the starter solenoid.

As for the fuel pump, the power for it also comes from the assist relay until the motor is started. Once started and oil pressure comes up, the oil pressure switch closes and power is maintained to the fuel pump

 

[Shadow91]

Okay, do you by chance know where the Slave solenoid is located? Little reading i did i saw it should be located around the shift mechanism or around the dash. Anyway to by pass it for testing purposes?

 

[alldodge]

The relay is on the motor. Follow the Yellow/Red wire from the starter back to the relay

 

[Shadow91]

Okay. So going over the slave solenoid, I have 12v at the big red wire, nothing at the big yellow wire and nothing at the small yellow wire (with key on)

With key in the 'start' position I have 12v at the small yellow wire but none at the bigger yellow wire that leads to the starter. I assume this would indicate a bad slave solenoid but would like to just confirm.

Also I have .05 ohm resistance from ignition to the slave solenoid. 12v at the starter. Roughly 6v at the coil. Checked every possible fuse I could find.

Also, anyone sure of the correct solenoid? I can't find any markings or numbers on the solenoid. Just with a google search I found 982187 for one that visually looks correct but not sure.

 

[bruceb58]

Just so you know, your model number points to a 1984 OMC Stringer drive which is actually very surprising its in an 86 boat. Usually they are only off by a year at most. You need to know this when you go to get parts.

Your fuel pump should be a mechanical one. You sure its electric?

The updated part number for that solenoid is 0985063

Sierra 18-5812 is also equivalent

 

[alldodge]

Okay. So going over the slave solenoid, I have 12v at the big red wire, nothing at the big yellow wire and nothing at the small yellow wire (with key on)

With key in the 'start' position I have 12v at the small yellow wire but none at the bigger yellow wire that leads to the starter. I assume this would indicate a bad slave solenoid but would like to just confirm.
.

That confirms its the solenoid