Timer Base Test

[joe7670]

70HP 1984 Johnson

Lost my spark and was going through steps in manual to troubleshoot.

First test for ignition switch passed.

Second test is the timer base/sensor coil test. Basically it says to test between the 4 leads with ohmmeter to get reading of 17 +-5

Maybe i'm missing something, but I get no ohm reading on any combination of the leads. Also did the test to ground to see if it's shorted out, but that's fine.

Tested ohmmeter on something else and the meter is working.

Before I go replacing it, am I supposed to check between leads with ohmmeter in any other fashion? or test some other way?

 

[jay_merrill]

Re: Timer Base Test

You have 4 leads. Three are sensor coil leads and one is a common lead. There are two basic ohms tests - coil lead to common lead and coil lead to ground.

Test the individual sensor coil leads to the common lead, one at a time. You should get the values specified in your manual. If the values that you get exceed the plus/minus values, you timer base is bad and should be replaced. This may be true of one lead or all of them.

Also test the sensor coil leads to ground, one at a time. While I don't know the spec for you motor, it should probably be "infinity." If it reads zero on any of the leads, that circuit is shorted to ground somewhere and the timer base is bad.