71 60ESL71C reverse battery cables amplifier damaged

"My son inadvertently installe

"My son inadvertently installed the battery with the cables reversed on my 71 Johnson 60ESL71C. When the starter turned backward I noticed what happened.
I know this fries the rectifier, and after correcting the connections, checked the charging output and it was dead. Replaced rectifier, and it now charges well. Used the boat last weekend without incident. Ran very well for a couple days. However I now have had a slow progression of performance issues, first it started bogging out at WOT, but only then. Today, it's gotten to the point where it will only idle, any throttle under load ( in gear) kills it. I can however rev it up in neutral ok. I am thinking the reverse battery cable incident has damaged the amplifier, is that something that would get killed by this?
Is the amplifier a go / no go type of component, where a failure means it won't run at all? Or can it simply degrade or be damaged enough to deliver a weak spark and run badly? Checked spark plugs and they are wet with fuel. ( new plugs didn't help).
Fuel pump is recent, and screen is clean. No fuel delivery issues that I can see, short of a carb teardown to check those.
Battery is new ( and properly charged) and connections are solid. I know a strong battery is needed for this type of ignition and it's always been well maintained and never discharged.

Any ideas appreciated.

Thanks / Craig"

"Craig... The amplifier (p

"Craig... The amplifier (pulsepack) simply provides voltage to the coil, and since the engine idles, I'd consider it to be okay.

However, to be on the safe side, check the amplifier out 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 energerizing the pulsepack with the required voltage needed for its proper operation.
********************
(Battery Capacitance Dischage Powerpack Test)
Various OMC Engines - 1968 to 1972)
(J. Reeves)

Purchase a small 12v bulb at your local automotive parts store (the 12v bulb is to look like a flashlight bulb, not a headlight bulb). Solder two wires to that bulb, one to the side of the bulb (ground), and the other to the positive point. You might use a bulb of a somewhat lower voltage to obtain a brighter glow... just a suggestion.

Remove the spark plugs. With the key in the on position, make sure that you have 12v going to the pack at the terminal block (purple wire). Now, connect the ground wire from the bulb to any powerhead ground. Connect the wire from the positive point of that bulb to the powerpack wire that is connected to the coil wire on the terminal board (blue wire).

Crank the engine and observe that bulb closely (CLOSELY!). If that bulb glows even the slightest bit, the powerpack is okay. It may be a very dim glow... just so it glows! If it doesn't glow, the pack has failed.

Keep in mind, that type powerpack (Battery Capacitance Discharge) demands a top notch battery of at least 70 amp hours. Any less will, in time, cause powerpack failure.


The rpms are controled elsewhere. From what you've said, I'd be more inclined to suspect a sticking timer base (retarded spark) or fouled carburetors, failing ignition coil (if spark is weak), something of that nature."

"Joe, thanks for the advice, i

"Joe, thanks for the advice, it is greatly appreciated. It will be a week before I can check the boat out further, so I will post back next weekend after I have a chance to test it out.
Have a great day sir....

Craig"

"Hi Joe, just to update you, t

"Hi Joe, just to update you, the ignition system checked out fine. What I found was this...I found that the #3 cylinder was not firing. ( disconnect plug wires while running, that cylinder was missing)
After noting a healthy spark, I moved on to checking fuel. I removed the airbox and opened the drain screw to the #3 carb.. no fuel in it!
Further inspection revealed that the airbox was pinching the fuel line to that carb, just slightly. I removed the line, pumped the bulb and got gas out of it. So, replaced the piece of fuel line, re-assembled and it was "much" better, although I couldn't launch it and test it on the water due to weather. That cylinder now fires so it looks pretty good, but final judgement will come next weekend.
Also, I did a compression test a week ago, and the results were 145, 145, 135 ( 135 is #3). Just for kicks I pulled off the head and inspected the cylinders and pistons and everything looked excellent, no scores or pits and extremely clean, not much carbon buildup.

So, all in all I think I am good, and thank you once again for your help....

Craig"

help!!! I also have a 60esl71c

help!!! I also have a 60esl71c johnson 60hp and I cannot start it! It fires as I release the key like its backwards??? It turns over but will not fire until I let back on the key which pops a couple times and dies??? Can anyone help?