[flstanleyii]

I have a '72 80hp, 4 cylinder Merc (serial # 3312746) that has no spark to any of the plugs. With the help of this forum, I believe I've isolated the problem to a bad trigger. At Laddies suggestion, in his post to Bryan22 on June 16, 2005, I disconnected the mercury switch, placed the engine at TDC, disconnected the distributor side terminals, jumped the brown and white posts on the 3 terminal side of the switch box and arced the black post to ground. With the switch turned on, I do have fire, which indicates a bad trigger. As parts are hard to find for this year of engine, I'd like to replace the entire distributor, if I can, but of course that means going to used parts. Prior to spending a lot of time and money on a "pig-in-a-poke", is there anyway to test a trigger with the distributor out of the engine? I have a couple of leads on used distributors but they've already been removed. I've checked the forum archives for some kind of a test, but have had no luck. As this is my first posting to this group, perhaps someone could point me in the right direction within the forum or perhaps knows of a way to test a used trigger if the topic hasn't been covered before?? As always, any and all comments would be greatly appreciated!!Thanks in advance!!Frank

[Laddies]

With the trigger wires hooked up crank the engine with the starter, you must have 9 1/2 volts on the white post with the starter turning the engine, ck the brown trigger wire 9 volts min., ck between the blk and the white wires with a DVA you should have 3 volts, low voltage between them means a bad trigger--Bob

[flstanleyii]

Thanks, Bob!!I have an extra pair of hands coming by and when they get here, I'll give that a try. However, if worse comes to worse and it is the trigger, any way to test one that's been removed from the engine??Thanks again!!Frank

[Laddies]

Sure just hook up the wires and turn the dist. by hand, you can't ck for starter load however and remember to stay away from the high tension lead

[timmathis]

Yas that is right if your trigger has A roter on it. If not you can test it with A feeler guage.