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Testing timer base on 1968 Evinrude 100hp

A

autoarcheologist

Member
I'm so close to getting our boat back on the water, but I think my timer base might be bad.

i have spark if I set the distributor to one of the spark plus leads and tap the timer leads together, so I know the amplifier, coil, cap and rotor are all good.

but as soon as I plug everything back together properly and crank it I don't get a spark.

The amplifier and coil are new from CDI. The wiring harness is all new, as is the rectifier and spark plugs.

If I check the resistance of the timer base I get 5.4 Ohms, which is right in spec.

I have tried various air gaps from 0.010" to 0.020 to 0.028 with no change.

I tried looking for a voltage jump from the leads and only saw maybe 0.1 V when cranking.

Does anybody know how much voltage I should see from the timer?

A new new timer base is over $150 so I'm looking for any other ideas or tests before I order a new one. It was working last summer, and I'm not sure why it would suddenly die with little use.

Thanks!
Ian
 
On that model, as it aged, the electric starter would pull so many amps, current, voltage... whatever you prefer to call it that it interfered with the amplifier. The cure for that problem was as follows:

********************
(Voltage Drop To Battery Capacitance Discharge)
( Pulsepack When Electric Starter Is Engaged)
(J. Reeves)

On the older Battery Capacitance Discharge ignition systems (1968-1972), the electric starter reaches a point, even with a top notch battery, whereas the starter will draw excess voltage/current/whatever which results in a voltage drop to the pulsepack. The cure is to purchase a diode which is capable of handling 12 volts and installing it between the starter terminal of the starter solenoid (NOT the battery cable terminal) and the wiring terminal that supplies voltage to the pulsepack.

The diode must be installed so that the current flows from the starter terminal of the solenoid to the pulsepack... NOT vice versa. When that diode is installed in this manner, when the key is turned to the start position, the voltage that is applied to the starter is also applied directly to the pulsepack via the diode effectively eliminating the voltage drop and energizing the pulsepack with the required voltage needed for its proper operation.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
********************

I can't pull from memory the exact gap distance between the timing sensor and the metal rotor but .028 (exactly) comes to mind... whatever it is I'm pretty sure it's printed in on the timer base itself. Check the sensor for whatever the ohm reading should be in your manual (I don't have that book)

Note that a timing sensor test can simply be sliding a feeler gauge past the sensor excite point (center).... that should fire the coil if it's good.

If the ohm reading of the sensor checks out, your problem is usually simple one but one that normally drives a mechanic nuts..... a loose wire, a wire that looks great but is broken internally, a tight wire terminal but one that has corrosion buildup (usually happens when sitting) that is interfering with the circuit.
 
Thanks for the help Joe, your replies to countless other threads have helped me get this far.

The resistance spec for the sensor is 4.0-6.0 Ohms, and I'm reading 5.4-5.5 so that specs out.

I also checked for continuity on the wires going to the sensor. They're new, but it's possible I pinched one during installation, but they checked out.

You were spot on with the distance spec, it's 0.028" and that's what it's set to now.

Unfortunately I can't test the sensor when installed. But I guess I could remove and use jumper wires to see if it will fire the pulsepack. If it will I assume I'm getting a big voltage drop, and I'll hunt down a diode. I wanted to build a DVA meter anyway, so it's a good excuse to pick up a few parts if I can find a Radio Shack that's still open.

Thanks again Joe, I will report back!

Ian
 
autoarcheologist said:
Unfortunately I can't test the sensor when installed. But I guess I could remove and use jumper wires to see if it will fire the pulsepack. Ian
Click to expand...

No need to disconnect anything to test the sensor... you just need to get at it to slide a feeler gauge past it to see if that fires the coil.
 
joereeves said:
No need to disconnect anything to test the sensor... you just need to get at it to slide a feeler gauge past it to see if that fires the coil.
Click to expand...

On this model the sensor is buried under the flywheel, cap and rotor. I'm getting good at pulling them off, but it still takes 10-15 minutes. And so I couldn't test it with the cap and rotor still hooked up, but Iwill just pull the primary lead going from the coil to the distributor cap and hold it close to a ground to watch for spark.

Every time I tried using a spare spark plug wire I didn't work, I assume they aren't solid core wires.
 
autoarcheologist said:
Every time I tried using a spare spark plug wire I didn't work, I assume they aren't solid core wires.
Click to expand...

The HT leads should all be solid steel wire core leads. And yes I know that you needed to pull the flywheel, dist cap and Bakelite rotor... I just meant that there was no need to disconnect the wiring.
 
​Maybe I missed it, but have you checked the voltage at the pulse pack input while cranking? Is the vacuum switch working?
 
fdrgator said:
​Maybe I missed it, but have you checked the voltage at the pulse pack input while cranking? Is the vacuum switch working?
Click to expand...

I had completely forgotten about that troublesome vacuum switch diaphragm #314237... a little crack is all it took!
 
I'm back to working on the boat, and still have the same issue.

I've also installed a new trigger sensor from CDI, and tried it at 0.028", 0.020" and even 0.018" with no luck.

I have installed the new "phase 2" rotor with smaller lobes.

I also took your advice Joe and measured the voltage while cranking at the powerpack. I found one ground wire at the battery that was suspect and fixed it. That brought the voltage while cranking up from 9.5V to just over 10V. I also checked at the battery cable connection to the starter, and on the starter side of the solenoid, and they also measure 10V while cranking. So I'm not sure how adding a wire with diode into the circuit will help. I tried it and it didn't make a difference.

If I have a coil wire hooked directly to the coil and held 1/4" from the block and crank the engine with the sensor hooked up it will not spark until I let off the key. I have seen another member with the same issue.

I also notice that the powerpack fires when the signal wire connection is broken, not when the wires are tapped together, but when they are pulled apart. Is this normal?

I also got the powerpack to spark by inserting a feller gauge between the rotor and sensor and it fired. But when I tried a feeler gauge in front of the sensor when the rotor isn't nearby it doesn't. Maybe not enough metal to activate the sensor?

Should I try it at 0.010" gap? I'm afraid to get too close and actually hit the sensor.

Doesn't anybody know how to test the timer base or sensor besides the resistance check?

CDI hasn't offered any other advice other than to test the voltage output from the pack while cranking.

Thanks,
Ian
 
As I remember it, they had a problem with accidental starting as soon as you turn the key on and without running the starter. The vacuum switch prevents voltage from feeding the pulse pack input until the engine is actually cranking.
 
fdrgator said:
As I remember it, they had a problem with accidental starting as soon as you turn the key on and without running the starter. The vacuum switch prevents voltage from feeding the pulse pack input until the engine is actually cranking.
Click to expand...

I appreciate the memory re-start gator. Also appreciate the confirmation backup Boobie.The old memory has been acting up a bit lately, will turn 85 this August and perhaps it's time to call it quits.
 
joereeves said:
I appreciate the memory re-start gator. Also appreciate the confirmation backup Boobie.The old memory has been acting up a bit lately, will turn 85 this August and perhaps it's time to call it quits.
Click to expand...

No! Don't call it quits, you're a treasure and the first person I thought of when I had trouble other than my 82 year old father who's an EECS.
 
kimcrwbr1 said:
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-133-5008.pdf
The anti reversing switch may be faulty? Did you check for shorts to the trigger to engine ground?
Click to expand...

The latest trigger sensor I got from CDI does not have a wire for the anti reverse switch, so it's currently not connected. The spring is still there, and I'm considering removing it just to rule it out.

I posted a long update a few days ago but for some reason I got a note saying that the administration needed to approve it. I will try to repost it again shortly.
 
Last edited:
Thank you to everybody who's helped to try and get this stupid motor running. It was a blast when it ran, albeit briefly, so I'm hoping to have it running again.


A little background, we bought the boat in 2014 and after running very briefly I noticed the insulation on the wiring was all flaking off and read about the problems they had with the wiring supplier in 1968. The CD module stopped working so I bought a new module, wiring harness and rectifier from CDI and installed them. The boat ran well for a few trips, then near the end of the summer it started then died on the dock and wouldn't restart.


Testing revealed the CD module wouldn't spark, so I sent it back under warranty.


After getting it back the most I can get out of it now is a spark when I tap the sensor wires together.


Since I started this thread I swapped in the new "Phase 2" timing rotor with smaller lobes, and a new magnetic sensor and wiring. So at this point the CD module, wiring harness, rectifier, rotor, neutral safety switch and magnetic sensor are all new. Plugs are new as well.


Here are the tests I have run this week:


I have gone through all the troubleshooting steps outlined in the CDI troubleshooting guide but I am not getting a spark through the sparkplug while cranking.


I have checked for battery voltage at the red/purple wire going to the CD module and read 12.6V. While cranking it stays just above 10V.


Joe I even built one of the diode wires like you recommend, but I measured the voltage at both sides of the starter solenoid and the voltage drops to about 10V in both cases. Should I still install the diode jumper?


If I disconnect one of the black/white wires coming from the sensor to the CD module I will get a spark. Not when tapping them together, but when I pull them apart to break the ground.


I can get this spark both with an ignition wire straight from the coil, as well as when I set the rotor and distributor to point to cylinder #2 and use cylinder #2 plugs and wire.


I have tried cranking with the original phase 1 rotor with wide lobes with also currently with the smaller phase 2 rotor.


If I crank the engine with the sensor connected but the coil wire going straight to a spark tester, it will only spark when I let go of the key. The sensor doesn't seem to be triggering anything.


I have tried setting the sensor gap to 0.028, 0.020, even as small as 0.018 with no spark. If I insert a feeler gauge between the sensor and rotor it will spark, but if I pass a feeler gauge in front of the sensor by itself it doesn't.


All signs are pointing to the sensor not working, or the CD module not accepting the signal from the sensor. Again the sensor is brand new and just installed this past week. I was having the same issue with the previous original sensor which is why I replaced it. Both sensors measure 5.0-5.1 ohms, within specs.


I removed the clipper circuit and the vacuum switch, the only safety switch is the safety switch for the starter. The anti-reverse spring is still installed, but there is no wire on the new harness for it so it's not connected to the green/black wire on the module.


My next step is to build a DVA adaptor and measure the voltage coming off the CD module, but since it will spark when I disconnect the sensor wires I believe it's working.


I'm also thinking of trying a 0.010" gap and see what happens. I will also try hooking up our old sensor again and pass something large and metal in front of it like a screwdriver to see if it sends a signal.


I can also try removing the anti-reverse spring completely to rule it out.


Any thoughts? I'm at my wits end trying to get this engine to spark properly so we can use it this summer!


Thank you again everybody!
Ian Lomax
Portland, Oregon
 
Thank you to everybody who's helped to try and get this stupid motor running. It was a blast when it ran, albeit briefly, so I'm hoping to have it running again.

A little background, we bought the boat in 2014 and after running very briefly I noticed the insulation on the wiring was all flaking off and read about the problems they had with the wiring supplier in 1968. The CD module stopped working so I bought a new module, wiring harness and rectifier from CDI and installed them. The boat ran well for a few trips, then near the end of the summer it started then died on the dock and wouldn't restart.

Testing revealed the CD module wouldn't spark, so I sent it back under warranty.

After getting it back the most I can get out of it now is a spark when I tap the sensor wires together.

Since I started this thread I swapped in the new "Phase 2" timing rotor with smaller lobes, and a new magnetic sensor and wiring. So at this point the CD module, wiring harness, rectifier, rotor, neutral safety switch and magnetic sensor are all new. Plugs are new as well.

Here are the tests I have run this week:

I have gone through all the troubleshooting steps outlined in the CDI troubleshooting guide but I am not getting a spark through the sparkplug while cranking.

I have checked for battery voltage at the red/purple wire going to the CD module and read 12.6V. While cranking it stays just above 10V.

Joe I even built one of the diode wires like you recommend, but I measured the voltage at both sides of the starter solenoid and the voltage drops to about 10V in both cases. Should I still install the diode jumper?

If I disconnect one of the black/white wires coming from the sensor to the CD module I will get a spark. Not when tapping them together, but when I pull them apart to break the ground.

I can get this spark both with an ignition wire straight from the coil, as well as when I set the rotor and distributor to point to cylinder #2 and use cylinder #2 plugs and wire.

I have tried cranking with the original phase 1 rotor with wide lobes with also currently with the smaller phase 2 rotor.

If I crank the engine with the sensor connected but the coil wire going straight to a spark tester, it will only spark when I let go of the key. The sensor doesn't seem to be triggering anything.

I have tried setting the sensor gap to 0.028, 0.020, even as small as 0.018 with no spark. If I insert a feeler gauge between the sensor and rotor it will spark, but if I pass a feeler gauge in front of the sensor by itself it doesn't.

All signs are pointing to the sensor not working, or the CD module not accepting the signal from the sensor. Again the sensor is brand new and just installed this past week. I was having the same issue with the previous original sensor which is why I replaced it. Both sensors measure 5.0-5.1 ohms, within specs.

I removed the clipper circuit and the vacuum switch, the only safety switch is the safety switch for the starter. The anti-reverse spring is still installed, but there is no wire on the new harness for it so it's not connected to the green/black wire on the module.

My next step is to build a DVA adaptor and measure the voltage coming off the CD module, but since it will spark when I disconnect the sensor wires I believe it's working.

I'm also thinking of trying a 0.010" gap and see what happens. I will also try hooking up our old sensor again and pass something large and metal in front of it like a screwdriver to see if it sends a signal.

I can also try removing the anti-reverse spring completely to rule it out.

Any thoughts? I'm at my wits end trying to get this engine to spark properly so we can use it this summer!

Thank you again everybody!
Ian Lomax
Portland, Oregon
 
Alright, I'll break this into multiple posts. Ha.

Thank you to everybody who's helped to try and get this stupid motor running. It was a blast when it ran, albeit briefly, so I'm hoping to have it running again.


A little background, we bought the boat in 2014 and after running very briefly I noticed the insulation on the wiring was all flaking off and read about the problems they had with the wiring supplier in 1968. The CD module stopped working so I bought a new module, wiring harness and rectifier from CDI and installed them. The boat ran well for a few trips, then near the end of the summer it started then died on the dock and wouldn't restart.


Testing revealed the CD module wouldn't spark, so I sent it back under warranty.


After getting it back the most I can get out of it now is a spark when I tap the sensor wires together.


Since I started this thread I swapped in the new "Phase 2" timing rotor with smaller lobes, and a new magnetic sensor and wiring. So at this point the CD module, wiring harness, rectifier, rotor, neutral safety switch and magnetic sensor are all new. Plugs are new as well.


Here are the tests I have run this week:
 
Thank you to everybody who's helped to try and get this stupid motor running. It was a blast when it ran, albeit briefly, so I'm hoping to have it running again.

A little background, we bought the boat in 2014 and after running very briefly I noticed the insulation on the wiring was all flaking off and read about the problems they had with the wiring supplier in 1968. The CD module stopped working so I bought a new module, wiring harness and rectifier from CDI and installed them. The boat ran well for a few trips, then near the end of the summer it started then died on the dock and wouldn't restart.

Testing revealed the CD module wouldn't spark, so I sent it back under warranty.

After getting it back the most I can get out of it now is a spark when I tap the sensor wires together.

Since I started this thread I swapped in the new "Phase 2" timing rotor with smaller lobes, and a new magnetic sensor and wiring. So at this point the CD module, wiring harness, rectifier, rotor, neutral safety switch and magnetic sensor are all new. Plugs are new as well.

Here are the tests I have run this week:

I have gone through all the troubleshooting steps outlined in the CDI troubleshooting guide but I am not getting a spark through the sparkplug while cranking.

I have checked for battery voltage at the red/purple wire going to the CD module and read 12.6V. While cranking it stays just above 10V.

Joe I even built one of the diode wires like you recommend, but I measured the voltage at both sides of the starter solenoid and the voltage drops to about 10V in both cases. Should I still install the diode jumper?

If I disconnect one of the black/white wires coming from the sensor to the CD module I will get a spark. Not when tapping them together, but when I pull them apart to break the ground.

I can get this spark both with an ignition wire straight from the coil, as well as when I set the rotor and distributor to point to cylinder #2 and use cylinder #2 plugs and wire.

I have tried cranking with the original phase 1 rotor with wide lobes with also currently with the smaller phase 2 rotor.

If I crank the engine with the sensor connected but the coil wire going straight to a spark tester, it will only spark when I let go of the key. The sensor doesn't seem to be triggering anything.

I have tried setting the sensor gap to 0.028, 0.020, even as small as 0.018 with no spark. If I insert a feeler gauge between the sensor and rotor it will spark, but if I pass a feeler gauge in front of the sensor by itself it doesn't.

All signs are pointing to the sensor not working, or the CD module not accepting the signal from the sensor. Again the sensor is brand new and just installed this past week. I was having the same issue with the previous original sensor which is why I replaced it. Both sensors measure 5.0-5.1 ohms, within specs.

I removed the clipper circuit and the vacuum switch, the only safety switch is the safety switch for the starter. The anti-reverse spring is still installed, but there is no wire on the new harness for it so it's not connected to the green/black wire on the module.

My next step is to build a DVA adaptor and measure the voltage coming off the CD module, but since it will spark when I disconnect the sensor wires I believe it's working.

I'm also thinking of trying a 0.010" gap and see what happens. I will also try hooking up our old sensor again and pass something large and metal in front of it like a screwdriver to see if it sends a signal.

I can also try removing the anti-reverse spring completely to rule it out.

Any thoughts? I'm at my wits end trying to get this engine to spark properly so we can use it this summer!

Thank you again everybody!

Ian Lomax
Portland, Oregon
 
Thank you to everybody who's helped to try and get this stupid motor running. It was a blast when it ran, albeit briefly, so I'm hoping to have it running again.

A little background, we bought the boat in 2014 and after running very briefly I noticed the insulation on the wiring was all flaking off and read about the problems they had with the wiring supplier in 1968. The CD module stopped working so I bought a new module, wiring harness and rectifier from CDI and installed them. The boat ran well for a few trips, then near the end of the summer it started then died on the dock and wouldn't restart.

Testing revealed the CD module wouldn't spark, so I sent it back under warranty.

After getting it back the most I can get out of it now is a spark when I tap the sensor wires together.

Since I started this thread I swapped in the new "Phase 2" timing rotor with smaller lobes, and a new magnetic sensor and wiring. So at this point the CD module, wiring harness, rectifier, rotor, neutral safety switch and magnetic sensor are all new. Plugs are new as well.

Here are the tests I have run this week:

I have gone through all the troubleshooting steps outlined in the CDI troubleshooting guide but I am not getting a spark through the sparkplug while cranking.

I have checked for battery voltage at the red/purple wire going to the CD module and read 12.6V. While cranking it stays just above 10V.

Joe I even built one of the diode wires like you recommend, but I measured the voltage at both sides of the starter solenoid and the voltage drops to about 10V in both cases. Should I still install the diode jumper?

If I disconnect one of the black/white wires coming from the sensor to the CD module I will get a spark. Not when tapping them together, but when I pull them apart to break the ground.

I can get this spark both with an ignition wire straight from the coil, as well as when I set the rotor and distributor to point to cylinder #2 and use cylinder #2 plugs and wire.

I have tried cranking with the original phase 1 rotor with wide lobes with also currently with the smaller phase 2 rotor.

If I crank the engine with the sensor connected but the coil wire going straight to a spark tester, it will only spark when I let go of the key. The sensor doesn't seem to be triggering anything.

I have tried setting the sensor gap to 0.028, 0.020, even as small as 0.018 with no spark. If I insert a feeler gauge between the sensor and rotor it will spark, but if I pass a feeler gauge in front of the sensor by itself it doesn't.

All signs are pointing to the sensor not working, or the CD module not accepting the signal from the sensor. Again the sensor is brand new and just installed this past week. I was having the same issue with the previous original sensor which is why I replaced it. Both sensors measure 5.0-5.1 ohms, within specs.

I removed the clipper circuit and the vacuum switch, the only safety switch is the safety switch for the starter. The anti-reverse spring is still installed, but there is no wire on the new harness for it so it's not connected to the green/black wire on the module.

My next step is to build a DVA adaptor and measure the voltage coming off the CD module, but since it will spark when I disconnect the sensor wires I believe it's working.

I'm also thinking of trying a 0.010" gap and see what happens. I will also try hooking up our old sensor again and pass something large and metal in front of it like a screwdriver to see if it sends a signal.

I can also try removing the anti-reverse spring completely to rule it out.

Any thoughts? I'm at my wits end trying to get this engine to spark properly so we can use it this summer!

Thank you again everybody!
Ian Lomax
Portland, Oregon
 
Joe,

I tried adding a wire like you suggested here, but when I measure the voltage drop on both sides of the starter solenoid I get about 10V, the same as I measure at the red/purple wire going to the CD module. I'm not sure how the extra wire is going to help, but I'm willing to try just about anything at this point.

Thanks,
Ian


joereeves said:
On that model, as it aged, the electric starter would pull so many amps, current, voltage... whatever you prefer to call it that it interfered with the amplifier. The cure for that problem was as follows:

********************
(Voltage Drop To Battery Capacitance Discharge)
( Pulsepack When Electric Starter Is Engaged)
(J. Reeves)

On the older Battery Capacitance Discharge ignition systems (1968-1972), the electric starter reaches a point, even with a top notch battery, whereas the starter will draw excess voltage/current/whatever which results in a voltage drop to the pulsepack. The cure is to purchase a diode which is capable of handling 12 volts and installing it between the starter terminal of the starter solenoid (NOT the battery cable terminal) and the wiring terminal that supplies voltage to the pulsepack.

The diode must be installed so that the current flows from the starter terminal of the solenoid to the pulsepack... NOT vice versa. When that diode is installed in this manner, when the key is turned to the start position, the voltage that is applied to the starter is also applied directly to the pulsepack via the diode effectively eliminating the voltage drop and energizing the pulsepack with the required voltage needed for its proper operation.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
********************

I can't pull from memory the exact gap distance between the timing sensor and the metal rotor but .028 (exactly) comes to mind... whatever it is I'm pretty sure it's printed in on the timer base itself. Check the sensor for whatever the ohm reading should be in your manual (I don't have that book)

Note that a timing sensor test can simply be sliding a feeler gauge past the sensor excite point (center).... that should fire the coil if it's good.

If the ohm reading of the sensor checks out, your problem is usually simple one but one that normally drives a mechanic nuts..... a loose wire, a wire that looks great but is broken internally, a tight wire terminal but one that has corrosion buildup (usually happens when sitting) that is interfering with the circuit.
Click to expand...
 
Joe Reeves. Now I will have to respect my elders. I turned 78 in Jan. :cool: And don't you dare call it quits !!!!!!!!!
 
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