My cousin has this engine. He said he replaced the amplifier about a year before it went bad this last time. I am an electronics technician and good with engines as well. I am pretty sure the amplifier is dead again, especially after doing a search in this forum and seeing the other threads related to dead amplifiers.My questions:1. In one thread, someone said that there might be a way to replace the amplifier with an ignition coil or something. Has anyone had any luck in that area? If so, any plans/schematics available?2. This engine has two "dingle-balls" in it. Two epoxy balls about 1" in diameter with wires going out of them. Schematic in the Johnson/Evinrude manual for this engine makes no mention of them that I can see. I have seen mecury switches on engines before that sense the tilt of the engine and will not allow spark if the engine is tilted up - out of the water. These do not seem to care anything about the tilt of the engine. I measure across them with an ohmmeter aand reposition them and notice no change in resisitance reading. What are they? Please no jokes regarding the obvious please }-)3.) What is the purpose of the amplifier? Timing comes from the points, spark "amplification" is usually done by the ignition coil. I can't figure out the purpose of this module.4.) Has anyone ever tried to remove the epoxy in one of of these modules and repair it? Seems like someone could make a small fortune repairing these if they could get to the parts inside. I have found a company called Dynalloy in Indiana that makes something called "Uresolve". It seems that this can be used to remove the epoxy stuff and unpot the components, but I can't seem to find a source for the stuff in small quantities.5.) Does anyone have a schematic for the amplifier?Thanks very much for any help you can provide!Please reply to the forum and send any documents to:mank@-removethis-andthe-dashes-bardstowncable.net
Are you sure your dealing with a 1979, 85 here? That engine should have 2 amplifiers, with four ignition coils. Those epoxy balls you speak of are blocking diodes. Thats why I question if we're talking about the right engine here.
The dingle balls are blocking diodes so the current to the gearshift doesn't interfere with the rest of the motor's electics. Your ignition system may have points? If so, you should start by cleaning those. Amps are upwards of $300. I know the early 3-cyls had points, but I'm not sure if the early V-4s did. I'm thinking they had an electronic pick-up from the start (I'm not sure of the 69s. That's why the year is so important, model number is all we need).The amplifier boosts battery voltage to the coils at electronically switched times. The first triggers used were "maker" points. Magnetic triggers came later. Maker points fire the sparkplugs when they make contact. Magnetos and regular battery ignitions have breaker points that fire the sparkplug when they break contact. So you can't put a conventional ignition system on your motor. The timing would be backwards.Some potting can be melted out of electronics by baking them in an oven at about 225 degrees F. Make sure you put a drip pan below. And most of all...do it when the wife is AWAY!If that's an original amplifier, it's shot. Time seems to be an enemy of those. I'd be amazed if any are still in service.
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Thank you all for replying.I appologize to the forum for not having my stuff in one sock, but here is the correct info I got from my cousin:1972 90(he thinks) HP with a 125HP powerhead.In the Johnson/Evinrude manual by Clymer for 1.5-125HP 1956-1972 engines, the correct schematic is the last page of the book (382).I know we verified the engine numbers with a boat shop in Wisconsin and were directed to that schematic.The schematic shows a stator and pickup and no points.I do not remember all the readings I had gotten before that led me to believe the pulse pack is bad.I did another search on this site and found a test using a 12V light bulb connected between ground and the blue wire coming from the looking for ANY kind of glow from the bulb. According to that test, any glow shows Pulse pack is good.So, if it is bad, can I take the stator pulses and feed into solid state voltage inverter and use that inverter's output to feed a traditional coil/condensor?It seems like alot of money to pay for something that is probably a simple circuit.Any help would be greatly appreciated. I will do the lightbulb test and get back with you all.Thanks again!!!!
Hmmm... I don't know how I got the same post two hours apart? Anyway, 1969-72 V4 ignitions are 12V battery-powered, using either points (85hp, 1971 100hp) or a sensor (115hp, 125hp, 1972 100hp) as a trigger. You can mount either system on any of the motors - all the cranks have both the cam for points & two holes to hold the sensor ring. If your amp is about 4" wide you have the point, if it's 5&1/2" wide and the back of the box has two/three levels, you have the sensor system. Obviously, you can pull flywheel & look also. Check that you're getting 12V to the box (red wire) with the ignition to ON. Rapair says to test the sensor box by momentarily touching together the two leads that go to the sensor (often both black with white stripe). Pull the fat wire going from the coil to the distributor (under the flywheel) & place it near a ground. You should get a spark when you touch the two sensor leads together. If you have the instrument to measure it, the box should send a 150V pulse to the coil (on the blue wire). To fire the points-based box, momentarily ground the single wire leading to the points, check for spark and/or 150V. Be advised that OMC put a ton more ground wires in some of these systems than show up on wiring diagrams, particularly extra ones leading to various things under the flywheel.Two of the 4 1969-72 V4s I've worked on over the last couple years had original amps in them that functioned fine (or at least they'd been in there a long time). I'm told the key is to use a big battery & clean connections, so that the amp box is always supplied a fairly ripple-free 12V. Reversing the battery connections will kill an amp right away (as well as the fuse & rectifier). We get questions on these all the time, please let us know if you find any useful workarounds.
Be aware also that this system has a anti-reverse spring under the stator, and around the crankshaft. It is held by friction, and can wear in two. This will ground out the system. You should have a minimum of 9 1/2 volts at the purple wire going to the pulse-pak when cranking.
Again, thank you all for your speedy assistance.Both batteries have died since we last tested and will not hold a charge. Considering what has been said about the importance of having a good, fully charged battery, we felt it silly to try and test with an automotive battery. Maybe it has the cranking amps, but why risk the ambiguity when performing tests and I do not want to waste your all's time any more than needed.The pulse-pack is a very new looking OMCModel/Part# 389550Other Numbers from the Engine:From Transom Mount Serial# plate: Ser.# E01080 Mod.# 125183CFrom Intake Manifold: 316652From Exhaust cover inspection plate: 310523From Head (not power head) 316464I am wondering if that OMC part# means anything to anyone?I went to a website and found a CDI catalog in pdf format. (Didn't know if I can post websites or not so I did not list URL here).In that catalog, I found that the cross for an OMC part# 389550 is a CDI/Rapair # 113-7123In that same pdf document I went to page 32 and it says the 113-7123 is for a 1971 100HP engine.Anything for a 1972 100HP or 125HP engine should be the Rapair# 113-8362.I could not find an OMC link on the web to find what OMC says should be the proper module for a 1972 125HP Evinrude.I am not sure if any of that matters even, since I have not determined, recently and for sure, using the tests you fine people have relayed to me, that the pulse-pack is bad. I do find it interesting, however, that the CDI catalog says the OMC part I have is for a 1971 100HP and not the 1972 125HP engine my cousin and I believe we have. Which brings me to my next question:How can I be sure, with the model and serial#'s I have found that the engine I THINK I have is the one I am truly dealing with? It seems to me that a plate on the transom mount bracket can not tell me which powerhead I actually have installed.Also, the Clymer manual says I can find the model# of the power head on a "welch plug" or "welsch plug" and shows a "typical" location and a picture of a 1.5HP engine. I can not find any such plug on this engine's power head (I assume the powerhead is the same as what I would call the BLOCK of an engine in a car, NOT the HEAD that has the valves and sparkplugs on it). Is this welsch plug a freeze plug of some kind?Do any of you fine people know where on this powerhead/block I can find a model# and how I can use it to ascertain what the HP of this engine really is so I can figure out which pulse-pack/amplifier I really need to have? This is not at all an overwhelming task for me, but that CDI catalog has me wondering if I have the right pulsepack/amplifier now and perhaps this one failed because it is under-rated for what I truly have.Ledgefinder wrote:Check that you're getting 12V to the box (red wire) with the ignition to ON. Rapair says to test the sensor box by momentarily touching together the two leads that go to the sensor (often both black with white stripe). Pull the fat wire going from the coil to the distributor (under the flywheel) & place it near a ground. You should get a spark when you touch the two sensor leads together. If you have the instrument to measure it, the box should send a 150V pulse to the coil (on the blue wire). To fire the points-based box, momentarily ground the single wire leading to the points, check for spark and/or 150V. Be advised that OMC put a ton more ground wires in some of these systems than show up on wiring diagrams, particularly extra ones leading to various things under the flywheel.<end of quote>I guess I have the points-based ignition then, since there are only four wires coming out of my OMC pulsepack. One red, one blue, one purple and only ONE Black with white stripe going towards the distributor. (Not two as in the sensor version)I will also check the anti-reverse spring RJOHNSON mentioned. I assume by "grounding the system" you mean grounding the pulses from the sensor to the pulsepack, since the sensor is the only thing under the stator where you say this spring is.... thanks for that tip.Thank you all for all of your help and I'll check back with my results.P.S. Can a moderator move this thread to another topic such as "1972 125HP has no spark" or some such thing? It may help others later when they search this forum and not be mislead by my incorrect topic.
389550, 4 wires total, and one going thin one going under the flywheel does sound like you've got a points-style amp. 125183 is 1971 Evinrude 125hp, which came with a sensor-based (not points-based) ignition, so someone may have swapped over to the points-based system. If you connect an ohmmeter to the one wire going under the flywheel, and slowly turn the flywheel (clockwise ONLY!, looking down from the top, or you may hurt the waterpump), you should get four open/closed circuit cycles per revolution. If you get none, you may have a sensor-based system, or a dead reverse spring, etc.. If you do get the four open/closed cycles, then you've got a set of points under the flywheel that may be working properly. By the way, if you can tell us whether the circuit opens or closes at TDC, that'd be of interest.You can test out your amp per the CDI Rapair instructions. Searching around the Internet (could try iboats.com first), you can find the CDI Rapair points amps for $200. Alternately, it should be possible to set up a standard battery/points ignition. The factory freeze plug is on the top of the port bank of cylinders - staring you right in the face. If the motor's been rebuilt, the plug may be replaced with one with no numbers. If the original plug's there, that'll tell you what you've got for a powerhead. It's difficult to tell from the outside otherwise, on those 1969-72 V4s. If you've gotta know, pull a head & mike the cylinders - the 125 was the only 3.5" bore motor before 1973. If I remember right, the 115s were 3.44", and the 85s & 100s were a hair smaller.