I have a 1972 100HP Johnson outboard.
It will turn over and start and run fine.
I can be crusing along and it is like somone shuts the key off. She just shuts right down.
It will then just start right back up and continue on. Somtimes it will just turn over and not fire at all. I then have removed the cover and just tapped on the coil on the upper right side of the motor and on the black brain box on the back and it will start. I have been told that the brain usually goes and does not work at all(not intermitet). I have also been told I have a short in the key. I have looked here but can't see anything. I would tend to think if I had a short here it would not even turn over? I have just ordered the service and parts manuals. Any one have any ideas? I have priced a brain at $360
and I hate to fork out that without being sure. The coil on the upper right has been replaced before(it was cracked visiablly). I call it a coil but it looks more like a little transformer to me. Does this control spark for all four cylinders? Help.
"Rick.... What you call a transformer is just that, at least that's what OMC calls it. However it's very unlikely that it would be intermitent. Usually the problem that you describe is due to a intermitent powerpack (the black box).
If it fails whereas you have no spark and stays that way, it can be easily and cheaply tested by yourself. Purchase a small 12v bulb (looks like a flashlight bulb) from a automotive type story. Solder two wires to the bulb... one to the side of the bulb (grd), and one to the center contact (pos). Connect the wire that is attached to the center of the bulb to the wire that leads from the pack to the primary lead of the coil (transformer). I believe that's a blue wire. Connect the other lead from the bulb to a ground somewhere on the powerhead. With the key on, and the SPARK PLUGS OUT, crank the engine and look closely (CLOSELY) at that bulb. If it glows ever so faintly, the pack is okay (at that moment anyway). If it doesn't glow, the p/pack is no good and will require replacing.
For the record, I still have two of the new revised powerpacks for that engine left in stock at a discounted price of $235.00.
NOTE... A short in the key (ignition switch) scenerio would pertain to the ignition systems that exist in the engines from 1973 on up, but that problem doesn't exist in your model. Let me know what you find out with the 12v bulb test.
"Josh... No, sorry. That's a completely different setup my friend. Always a good idea to have a spare pack as one never knows when that thing will act up, some never do.... but others! The spare pack also makes trouble shooting a snap too. Simply plug it in and try it.
Try this.... unplug the main large red plug at the engine. That makes the engine seperate from everything except the electric starter which you can energize at the solenoid. Remove the s/plugs so as not to start the engine accidently. Rig up something to check the spark and crank the engine over via a jumper at the solenoid. If you have no spark on either cylinder, it's a pretty safe bet that the pack has failed. Let me know what you find.
thanks for the input joe about how much am i lookingnat spending on a pack for a late 70's 50 hp evinrude thanks in advance josh hildreth ps i was the one that was having trouble with the lower unit for the 1979 25 hp johnson i got the new shifter dof and the gear and it works fine thank you joe also one more thing the motor dosent want to idle good it will idle until you try to advance the throttle and then it will die the plugs are very bad they are black and wet i tried to adjust the carb it runs beat at 3/4 turns out of setting i think that is runnig lean but it idles its fastet at that setting any ideas josh
Josh.... This conversation is running under the subject heading of a 1972 100hp problem. Start it anew if you intend to continue with it.
On the 25hp problem.... I suspect that the high speed jet in the float bowl is fouled and restricted. Fuel must flow through that H/S jet before it can get to anywhere else.
Pertaining to the 1979 50hp p/pack. They list for approximately $80.00 plus tax. I have a few new ones left in stock and will sell any one of them for $65.00 which will include shipping.
" Rick Artz.... I received a e-mail from you some time ago that stated that there is nothing in the body portion of my message. Later, I received a phone call from you. I've heard nothing since. I'd appreciate it if you would jot me off a e-mail to let me know what's going on. Nobody else has a problem receiving my e-mail. I've checked my setup and nothing is blocked. By any chance do you have something wrong with your mail reader?
