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Please help me diagnose ignition on 48 SPL

P

PhilSch

Regular Contributor
1994 48 SPL. Initially it had no spark on Cyl #2. Using the CDI ignition troubleshooting guide and a DVA meter I determined the power pack was bad. Put on a new power pack and also replaced the 25 year old coil pack which resulted in spark on both cylinders. Cleaned both carbs and it sounded like a new motor on muffs. Took it out to the lake and at idle it was severely vibrating with no power. Took her home and now no spark on either cylinder! Couldn't produce a spark even with tester set down to 1/4". Did all the tests per the CDI ignition guide and results were within spec (I think) which are listed below with the exception of the orange wires from power pack to coil primary posts described after the chart.

At the beginning of the test I disconnected the Black/Yellow wire from the power pack to eliminate the stop circuit as a possible issue.

Engine without SLOW function (Two Wire Trigger)
TestConnectedTestDisconnectedTest
WIREREAD TOOHMSResultDVAResultDVA Result
BrownBrown/Yellow800-1000900150-400300150-400300
BrownEngine GNDOpenOpen150-400280<2V0.004
Brown/YellowEngine GNDOpenOpen150-400290<2V0.006
Black/WhiteWhite/Black30-5042.5.6V or more10.4.6V or more15.7
Black/WhiteEngine GNDOpenOpen.6V or more4.3<2V0
White/BlackEngine GNDOpenOpen.6V or more4.3<2V0

The CDI guide says to check the DVA output from the orange wires from the power pack connected to the
primary posts of the coils. I did this with a wire piercing adapter to the red DVA lead and the black lead to engine ground. They should have 150V minimum and I get zero volts while cranking.

Brand new power pack failure after running just a few minutes?

One other question is the 0 volts from the timer base wires to engine ground. Supposed to be less than 2V but got nothing. Is that acceptable?
 
I'm a bit surprised no one had any suggestions for this ignition problem but fortunately I was able to get it diagnosed. The new coil is bad...it took a dump after less than a minute of run time.

There was one diagnostic test in the CDI troubleshooting guide I had not performed because I did not have a 10 OHM, 10 WATT resistor. I obtained one, hooked the orange primary coil wires to that instead of to the coil. 240 DVA on each wire proving the new power pack is fine. As mentioned in my first post those same wires show 0 volts when attached to the dead coil.
 
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