1971 Mercury 110 9.8 Basket Case

[ALH27]

I picked up a 1971 Mercury 110 9.8 for cheap with the knowledge that it didn’t run. What I didn’t know at the time was that this motor has the infamous Thunderbolt phase maker ignition. I now have more time and money into this thing than I’d originally intended and I still can’t get it to fire. Not even a cough or wheeze. No spark on either cylinder. I’ve read just about every forum post I can find to no avail. So I’ll start with the list of things I’ve done and tried, and maybe you guys can point me in the right direction:

- Rebuilt carburetor
- Rebuilt/repaired fuel pump
- New point insulator blocks
- Points set to .020 gap
- All new wiring with proper insulation
- Stator “kill switch” wire ran to ground
- New green coils
- Tested new coils with a multimeter. Coils fully connected to system - Primary circuit: .3 ohms. Secondary circuit: ~600 ohms. Coils fully disconnected from system - Primary circuit: .3 ohms. Secondary circuit: no readout (no continuity?)
- Ran the following diagnostics per CDI and got a spark on the jumper wire to ground on both coils:
“NO SPARK ON ANY CYLINDER:
Disconnect the Brown and White 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 sparks – check the points and points wires. If it fails to spark, inspect the ignition coil.”

I’ve inspected and re-inspected the points and points wires. The points aren’t pristine, but I’ve read they don’t have to be for this motor. The points wires are new and good.

So now I’m at a loss. Are my new coils bad? Bad points? Is my stator bad? How do I test the stator? I’m not sure what my next step should be. Thanks in advance for any guidance you guys can provide.

 

[1234Jerry]

I picked up a 1971 Mercury 110 9.8 for cheap with the knowledge that it didn’t run. What I didn’t know at the time was that this motor has the infamous Thunderbolt phase maker ignition. I now have more time and money into this thing than I’d originally intended and I still can’t get it to fire. Not even a cough or wheeze. No spark on either cylinder. I’ve read just about every forum post I can find to no avail. So I’ll start with the list of things I’ve done and tried, and maybe you guys can point me in the right direction:

- Rebuilt carburetor
- Rebuilt/repaired fuel pump
- New point insulator blocks
- Points set to .020 gap
- All new wiring with proper insulation
- Stator “kill switch” wire ran to ground
- New green coils
- Tested new coils with a multimeter. Coils fully connected to system - Primary circuit: .3 ohms. Secondary circuit: ~600 ohms. Coils fully disconnected from system - Primary circuit: .3 ohms. Secondary circuit: no readout (no continuity?)
- Ran the following diagnostics per CDI and got a spark on the jumper wire to ground on both coils:
“NO SPARK ON ANY CYLINDER:
Disconnect the Brown and White 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 sparks – check the points and points wires. If it fails to spark, inspect the ignition coil.”

I’ve inspected and re-inspected the points and points wires. The points aren’t pristine, but I’ve read they don’t have to be for this motor. The points wires are new and good.

So now I’m at a loss. Are my new coils bad? Bad points? Is my stator bad? How do I test the stator? I’m not sure what my next step should be. Thanks in advance for any guidance you guys can provide.

I am in the same boat as you. I just registered on iboats and found your post. I have a '72 Model 110 9.8 HP with the same problems. My new coils meter the same as yours. I installed new points and condenser. Good blue spark across 3/8" gap with old ignition coils, compression 105 on both cylinders. Ran for 10 mins in tank then died. No spark either cyl. I'm going to start a new thread that might get a response. I'm thinking a bad module or stator. I'm into this for $700 Canadian already. Let me know if you have made any progress. I'll do the same. Good luck! Jerry

 

[ALH27]

Unfortunately I don’t have an answer for you. I haven’t done anything more with the motor since I made this post other than check and recheck my wiring. I’m afraid my stator is fried, but I haven’t been able to find a good way to test it and I’m hesitant to spend another $300 if that’s not the problem. The confusing thing for me is, when I first brought this motor home, before I even touched any of the internals, I could at least get a snort out of it. But the wiring was horrible and the posts were falling out of the old coils, so I didn’t think I was doing any harm by replacing those things. Now I can’t get any spark at all. I’m lost. I’ll definitely share if I figure anything out.

 

[WarthogMan]

I'm in the same boat as you both with a 1973 Merc 110 (9.8 hp) with no spark. I have one good coil (I think) which tests the same as yours and now one bad coil with an open primary winding (see my thread on 'Ignition Coil Replacement). The motor is pristine with very low hours. The crazy thing is when I bought it (also for cheep) it ran well the first time I started it and now it has no spark. I was in the process of trying to find a lime green replacement coil but I am concerned that this might be a money pit with no hope. Let's keep in touch to see if someone has an idea to help us get these motors running. Thanks

 

[1234Jerry]

I picked up a 1971 Mercury 110 9.8 for cheap with the knowledge that it didn’t run. What I didn’t know at the time was that this motor has the infamous Thunderbolt phase maker ignition. I now have more time and money into this thing than I’d originally intended and I still can’t get it to fire. Not even a cough or wheeze. No spark on either cylinder. I’ve read just about every forum post I can find to no avail. So I’ll start with the list of things I’ve done and tried, and maybe you guys can point me in the right direction:

- Rebuilt carburetor
- Rebuilt/repaired fuel pump
- New point insulator blocks
- Points set to .020 gap
- All new wiring with proper insulation
- Stator “kill switch” wire ran to ground
- New green coils
- Tested new coils with a multimeter. Coils fully connected to system - Primary circuit: .3 ohms. Secondary circuit: ~600 ohms. Coils fully disconnected from system - Primary circuit: .3 ohms. Secondary circuit: no readout (no continuity?)
- Ran the following diagnostics per CDI and got a spark on the jumper wire to ground on both coils:
“NO SPARK ON ANY CYLINDER:
Disconnect the Brown and White 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 sparks – check the points and points wires. If it fails to spark, inspect the ignition coil.”

I’ve inspected and re-inspected the points and points wires. The points aren’t pristine, but I’ve read they don’t have to be for this motor. The points wires are new and good.

So now I’m at a loss. Are my new coils bad? Bad points? Is my stator bad? How do I test the stator? I’m not sure what my next step should be. Thanks in advance for any guidance you guys can provide.

My Merc is now running great. When I pulled my flywheel off again to recheck the points (as suggested by Faztbullet) I discovered that the positive wire from the conderser(CDI replacement) had been cut through by the flywheel (my bad). I was able to solder in a new piece a bit longer than the original and made sure that I had both wires well tucked back before I put the flywheel back on. Bottom line, I read your first post again and didn't see any mention of your condenser. Did you check or replace it? I am going to rant a bit about the specs I have found and give my readings from my module(red, # 336-4516) diode test in the hope that it may save someone some money or that someone can interpret my test results as I can't seem to find any info to compare the results with. on the update my post with some info and questions on the module and ignition coil secondary specs. I am out of room for this reply, so I will continue by replying to my post with the info. Take care, Jerry