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1988 260hp mercruiser

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baitbag

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I was helping a friend who just bought a 1988 cruisersinc with a 260 Mercruiser that has been sitting about 2 years. The previous owner probably didn't do a whole lot to winterize it. We haven't been able to get it started after changing the plugs, new batteries, new primed fuel filter, checked the shift interrupter switch, The distributor cap and rotor look ok. We've tried cranking it over after priming the carb with gas and also with starting fluid. We checked and saw spark on the one wire that we tested. The ground on the ignition module was cleaned. When cranking the engine it sounds like it wants to start, but won't. I suspect it is an intermittent spark. When the dist cap was off, we noticed that there was some rubbery looking sealant? around the pickup coil. Is that normal? What is the pickup coil ohm reading supposed to be? We are running out things to check. Any suggestions
 
Tests for Thunderbolt Ignition:


Tests for Thunderbolt Ignition:
With ignition key on AND BILGE WELL VENTILATED OF GAS FUMES!!!

#1 - Connect your voltmeter neg. lead to the engine ground and pos. lead to the white/red wire terminal at the dist. It should read 12 volts. Now turn key off.

#2 - If 12 volts is present, remove the coil spark wire from the distributor and connect it to a spark gap tester to ground. Remove the white/green lead from the dist. terminal. Turn the ign. key to on and strike the white/green lead to ground. If there is spark, replace the ignition sensor in the dist.

#3 - If there is no spark, substitute a new coil and repeat test #2. Now if you get spark, install a new coil. NO SPARK, replace ignition amplifier/timing module.

#4 - In #2, if there is No voltage present, disconnect the white/red wire and check it again for 12 volts. If 12 volts is present, replace the ignition sensor inside the dist. cap. If no 12 volts present w/it disconnected--ignition amplifier/timing module is shot and must be replaced.
 
If a new sensing coil is needed, does it just bolt-in or is there an air gap adjustment that needs to be set with a feeler gage etc.
 
If the ignition sensor/pick up is replaced it is a direct fit and no gap is needed.

It is not a coil.

It is what I call a Hall effect magnetic pick up.


The only issue will be the original sensor has two threaded studs for wire connections and ground was accomplished thru the distributor body. The new sensor will have a three wire pig tail with the two wires (white with green stripe and white with red stripe) will be bullet connectors vs ring terminals. Thus you need to make the two wires from the timing module the corresponding bullet connectors. Not sure if the bullet connectors for the timing module wires come in the kit or not. Also the new sensor as said has three wires and one is a black ground wire and that need to be attached to a close and good ground point.
 
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