1975 850 Mercury No SPARK %3cIMG SRC%3d%22httpwwwmarineenginecomdiscusclipartsadgif%22 ALT%3d%22%22%3e

I have a 1975 850 Merc that w

I have a 1975 850 Merc that when my father place in storage(garage) 14 years ago ran grrrrreat!!! I took it out and now it has no spark. Any suggestions??

HELP!!! PLEASE!!! Is there an

HELP!!! PLEASE!!! Is there anyone out there that knows the ignition system on this motor? Common problems? Things to check? The cover of the motor says "ThunderBolt Ignition"

Gilligan....This type of igni

Gilligan....This type of ignition system was very reliable but as with anything can go wrong. You will need a multimeter for these tests. Put the black probe to the case of the powerpack(ground) then with the red probe touch the red terminal of the powerpack. you should have 12v here with the ignition off. Then go to the white terminal and you should have 12v with the ignition on and while cranking. If you dont have these readings check your wiring and ignition switch. If they check ok disconnect the mercury switch from the brown terminal of the powerpack and check for spark again. If still no spark test the coil. To test coil disconect the the wires that come off it. Put your multimeter between the 2 wires that come off the coil you should have 0.01-0.02 ohms. Next put ohm meter between a good ground and the high tension lead and you should 57-73 ohms. If coil doesn t test to specs replace it. If it does then check power pack and distributor. The only way i check these 2 is to replace them with known good ones. Hope this helps and let us know what you find.

" most common problem is the t

" most common problem is the trigger,which happens to be the distributer also,take cap off as ive seen green oxidation cause a no spark.
most likely the "distrigger" though.
i have one or two "