Expert: Everett Peacock - 11/20/2008

Question
Hello I have an 87 Johnson 90HP. This summer the 10 yr old battery died. After replacing it the motor ran very rough and would surge and buck. I replaced all plugs and plug wires. I also replaced the VRO from generic to Johnson bran ( at dealers suggestion) with little change. I tried a spark tester and found plugs 1 and 3 had good spark, 2 was week and 4 non existent. During following tests 2 also had no spark. I checked all ground and removed the flywheel to look for broken wires. All looked good. I then unplugged the two and 5 prong plugs on the left power pack and used my ohm meter to test resistance. I found a difference when comparing my test to the right power pack. I now have the left removed and would like a definitive test for the power pack before I spend $100 on a new one. Can you help with this and does it sound like I and going down the right road?

Answer
if you test all the items for resistance and peak volt output and they are good then the pack is bad...   there is no reisitance checks for the power pack, just the items that attach to it are tested...sensor coil output when cranking shouild be .5 and 3 volts.. the charge coils should be somewhere aound 15 and up in peak volt output.. and allwayts check the kill circuit ....