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chris_v

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"My 1971 50hp.is trying to giv

"My 1971 50hp.is trying to give me an ulcer. I have had flawless use from this motor for many years until last night. At the launch I tried to start it but found it was not getting spark. After testing both plugs I was retesting the #1 plug (I always double check my sloppy work) when it suddenly started sparking. I retested #2 and found it also was sparking. So I reinstalled the plugs, replaced the cover (I have a great deal of confidence after double checking my sloppy work)and fired it up! I started and stopped it numerous times and had no more problems all night. If someone has a suggestion on where to start I would be very appreciative. Since I could do little more than look at obvious signs of loose connections at coils and powerpack, I am hoping for a similar experience suggestion."
 
"may i suggest looking for bar

"may i suggest looking for bare wires, especially ones that run near the motor. any small nick in a wire can cause it to ground out. Also, check your deadman switch. It may have been bumped and in the process of restarting you reconnected it"
 
"Relying on memory, I believe

"Relying on memory, I believe that the 1971 50hp model incorporated a pulsepack that required battery voltage to energize it. If so, read on.

It possible that you are encountering a intermitent powerpack, but hopefully not.

There's also a chance that the starter is intermitently drawing excessive voltage, in which case.......

(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."
 
"Is there a test procedure for

"Is there a test procedure for checking voltage drop to the pulse pack? Or is it a case of "it's not doing it now,good luck finding it". I have an ohm meter and plenty of time (maybe a little short on comprehension so I will read slowly). If putting a diode in is not expensive I could just go that route. Where? Radio shack?
I will also check the "dead man switch"."
 
"Diodes are cheap. Any diode t

"Diodes are cheap. Any diode that will handle 12 volts will work, and yes Radio Shack will have them."
 
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