Ok. So i have this engine with very weak spark. The spark is thin and yellow and can only jump a small gap on the spark tester. Here's what I have done so far.
Checked compression. About 115 across all 4 cylinders.
Engine is spinning fast on starter. New battery. Ground connections all cleaned. Terminals on battery cables replaced. Even tried different set of cables.
Tried disconnecting kill wire. No difference at all.
I made a DVA tester - stator resistance (624ohms) and DVA (260V) so all ok. Coil resistances all check ok on both primary and secondary coils. Timing base wires 1 to 3 and 2 to 4 ohms a little low (8ohms, 8.2ohms should be 10-20ohms). DVA across the sets i can get up to 1V if I let it crank for about 10 seconds. My homemade DVA tester has a diode in it and I think this will cause a voltage drop of 0.7V so I'm calling that test ok. I had the flywheel off and looks like one of the sensors on the timing base has been replaced in the past. The factory manual says to check each black/white wire (connected) from the timing base to ground and that I should get at least 150V on the DVA tester. It says that the timing signal rides on top of the stator voltage. The way I interpret this is that I should be getting pretty much the same reading as for the stator. On terminal 2 i get about 1V doing this. On terminal 12 I get about 15V. If I disconnect the wires and try again from the terminals I get the same. No one seems to talk about this test for the timing base much, only testing across the sets of wires. They say if the voltage jumps up then it can mean a bad timing base but doesnt say what it indicates if it doesnt jump up. Does this indicate a bad Power Pack?
The only other test the manual recommends doing is to adjust the sensors which I haven't tried doing.
Checked compression. About 115 across all 4 cylinders.
Engine is spinning fast on starter. New battery. Ground connections all cleaned. Terminals on battery cables replaced. Even tried different set of cables.
Tried disconnecting kill wire. No difference at all.
I made a DVA tester - stator resistance (624ohms) and DVA (260V) so all ok. Coil resistances all check ok on both primary and secondary coils. Timing base wires 1 to 3 and 2 to 4 ohms a little low (8ohms, 8.2ohms should be 10-20ohms). DVA across the sets i can get up to 1V if I let it crank for about 10 seconds. My homemade DVA tester has a diode in it and I think this will cause a voltage drop of 0.7V so I'm calling that test ok. I had the flywheel off and looks like one of the sensors on the timing base has been replaced in the past. The factory manual says to check each black/white wire (connected) from the timing base to ground and that I should get at least 150V on the DVA tester. It says that the timing signal rides on top of the stator voltage. The way I interpret this is that I should be getting pretty much the same reading as for the stator. On terminal 2 i get about 1V doing this. On terminal 12 I get about 15V. If I disconnect the wires and try again from the terminals I get the same. No one seems to talk about this test for the timing base much, only testing across the sets of wires. They say if the voltage jumps up then it can mean a bad timing base but doesnt say what it indicates if it doesnt jump up. Does this indicate a bad Power Pack?
The only other test the manual recommends doing is to adjust the sensors which I haven't tried doing.