I have a 1971 110/9.8 hp mercury that I picked up for $100. (the infamous phase maker ignition)
I suspect a bad stator but wanted to make sure before I spend $400+ on a new one.
I changed the insulator blocks which were badly cracked and I get some spark at low RPMs. However the spark is intermittent and sometimes stops entirely at higher RPMS. (I cranked with drill.)
I put an Oscilloscope on the + terminal of one of the coils and see the attached ("with points") image
It looks like something is shorting when the voltage gets to about 200V (I assume there is a Cap in the ignition that would just charge and stay high until points close)
To rule out the points I disconnected the green stator wire and hooked it up to the Scope
I then saw the attached (Open) image.
with the green wire floating I would have expected it to charge and then just hold the voltage but again something is shorting.
Any ideas?
Thanks for the help
I suspect a bad stator but wanted to make sure before I spend $400+ on a new one.
I changed the insulator blocks which were badly cracked and I get some spark at low RPMs. However the spark is intermittent and sometimes stops entirely at higher RPMS. (I cranked with drill.)
I put an Oscilloscope on the + terminal of one of the coils and see the attached ("with points") image
It looks like something is shorting when the voltage gets to about 200V (I assume there is a Cap in the ignition that would just charge and stay high until points close)
To rule out the points I disconnected the green stator wire and hooked it up to the Scope
I then saw the attached (Open) image.
with the green wire floating I would have expected it to charge and then just hold the voltage but again something is shorting.
Any ideas?
Thanks for the help
