1975 85 evinrude I'm lost

[river rat 26]

Have had an intermittant spark on #4 for a while that has gotten worse the last couple of weeks. I had swapped coils and the power pak, no differance. This weekend I swapped out the sensor coils(timer base) Took it out this morning and still had the same problem. While I was out there I ck'd the voltage at the battery and was getting 17 volts. Came home and swapped the rectifier with one off my parts mtr. and now I'm getting 13.5 like I'm supposed to but have little or no spark on #2 and #4 cyl, when I can get the mtr to start. Not sure where to go next, I don't understand what the rectifier could have to do with this problem. I did go ahead and try my other pak thinking maybe the 17 volts smoked the one that was on there but nothing changed. I know I'm missing something here, any one got any suggestions

 

[OBJ]

Re: 1975 85 evinrude I'm lost

Hi river rat. What it sounds like to me is you swapped out a bad part for a worse part. You had intermittent spark on #2 cylinder. Ya' swapped out the coil and power pack and had the same thing. Right so far?<br /><br />You then swapped out the timer base and now have little or not spark on either 2 or 4 cylinder. Sounds to me like neither timer base is any good.<br /><br />The rectifier does nothing for the spark. It just charges the battery. Sounds like you fixed the overcharge problem.<br /><br />Swap out the timer base for the original. If your back to square 1, probably the timer base is shot.

 

[river rat 26]

Re: 1975 85 evinrude I'm lost

Thanks for the quick reply OBJ, do you know if it is possible to remove the sensor coil from one timer base and put it in another? If I understand this thing right one coil is for 2 and 4 and the other is for 1 and 3. tell me if this is stupid and I'll get a new one. With an ohm meter all this old stuff is cking good, looks good too....RR

 

[OBJ]

Re: 1975 85 evinrude I'm lost

Sorry RR but the coils can't be interchanged....unless you have the way to dig them out and put the stuff around them again.<br /><br />Tell ya' what to do, if you don't have one, get an OEM manual for correct troubleshooting procedures. You should get 1.5 or higher volts from the timer base coils while cranking with a peak reading meter.<br /><br />The manual will pay for itself in no time.

 

[river rat 26]

Re: 1975 85 evinrude I'm lost

thanks again OBJ, got to go back to work tomorrow so I can't get back to this for awile but I'll let you know how it turns out...RR

 

[R.Johnson]

Re: 1975 85 evinrude I'm lost

Those sensor coils can be adjusted, Rapair sells a guage to do just that. See what kind of spark you have with the spark plugs removed. I have seen this problem blamed on a bad stator base on up to weak flywheel magnets. You have to remove the epoxy seal around the adjusting nuts. That seal just locks the nut in place, it is not an insulator. Looking down on the sensor, you will see that it sits in a cast recess in the stator ring with a shoulder that limits it's outward travel. To adjust, you loosen the two screws that hold it down. On the back of the sensor there is a small threaded shank with two jam nuts, the outer jam nut is locked in place with epoxy. This you have to remove to adjust. What I use is an old jeweler's graver that is a triangle shape that I ground back at about a 30 degree angle on the face to make a sharp chisel. You can make the same thing from a triangle shape needle file. This will let you cut away the epoxy without gouging the metal ring. Use a fast drying epoxy to relock the nut. The part # of the Rapair guage is R553-9702 the price as I recall is $10-$15. This guage has solved the no fire with the plugs in problem several times.

 

[river rat 26]

Re: 1975 85 evinrude I'm lost

Thank you RJ, that explains quite a bit. It surprised me that the timer base was so much harder to move with the fly wheel installed,so much so that I removed it a number of times and loosened all the screws on the ring the coils mount on tring to get the coils to spread(It seemed like they were rubbing the fly wheel) So this tool you spoke of must drop down over the crankshaft and allow you to see what if any adjustment is nessary. Have I got this right? Also it looks to me with the info you gave me that these coils could be removed and replaced if I had two timer bases with a bad coil each, does this sound right?...RR

 

[OBJ]

Re: 1975 85 evinrude I'm lost

My thanks to RJ....just when ya' think ya' got a handle on things.....ya' go and learn something else.....

 

[R.Johnson]

Re: 1975 85 evinrude I'm lost

The timer base is held down with 4 retaining tabs, remove these to remove timer base out of it's seat. Clean the seat, and delrin bearing ring, and lube with OMC moly-lube. If you don't have the sensor guage, set the sensors out to the limit of the casting boss.Here is a trick you can use, that is used in machine practice when fitting close fitting parts. Take a common household candle, and trim back to expose about 1/2 inch of wick. Use this to smoke the flywheel hub that rotates around the sensors. This will give a low flame with a lot of smoke, so things don't get hot. Tighten every thing down, rotate, remove flywheel, and check for fit. If the sensors are out to far, they will rub the soot off the flywheel. Check voltage before, and after this adjustment, you will be surprized. Yes! the Rapair guage goes over the crank, and show's the clearence.

 

[dolluper]

Re: 1975 85 evinrude I'm lost

good stuff r.j. nice to see old tricks

 

[river rat 26]

Re: 1975 85 evinrude I'm lost

Took today off to fool with this some more. Pulled the flywheel and it looked like one of the sensor coils had been rubbing so I put the original timer base back on. With everything back together ck'd for spark again, still no spark on #2 and #4. Disconnected the sensor wires at the pak and ck'd voltage while cranking. Had about .98vac on both pairs(not a peak reading meter) just wanted to see if they were the same. Swapped coil wires at the pack and had good spark on #2 and #4 while cranking. Swapped to my spare pack, now have fire on all four but #2 and #4 seem a little weaker. Kind of back where I srarted from. Ran mtr in the yard for about 30 min. and stiil had spark on all four(#4 was dropping in and out before) Also I get no rpm change when I pull the plug wire off #4, removeing plug wire one the outher three gives a noticable drop in rpm. I'm not sure what all this means, it seems by running mtr with the sensor coil rubbing I've killed one of my power paks? Is it likely that a power pak would be intermitant, also does having a weaker spark on one bank have to be related to the timer base? I'm gonna go put her on the lake and see how she does, if it will contiue to fire on all four I'll be content for now. How much are those e-tec's going for?.......

 

[river rat 26]

Re: 1975 85 evinrude I'm lost

I'm back, ran like a scaulded dog

 

[dolluper]

Re: 1975 85 evinrude I'm lost

check sensor coil and charge coil outputs --sensor coil remove pack connectors #2 and #4 lo ohems scale should read 8.5 ohems+ or- 2.0 ohems number 1 and 3 can be checked at connectors #9 and #12 but also disconnect from pack same reading ,then on high scale from leads #2 and ground should be infinity reading do same for the rest any read ing zero are bad----charge coil pack disconnect #7 and#8 high scale between them should read 630 ohems + or-50 ohems then between #7 and ground should be infinity hi scale also then same for #8 if either read zero bad replace or trace bad wire?? hope this narrows it down for you

 

[river rat 26]

Re: 1975 85 evinrude I'm lost

Another long run tonight. about 6 Hrs on the lake and the whole time she ran perfect, thank y'all for the insight in to how the electronics on this mtr work. Made all the differance in being able to understand the little I do.................Dolluper, had done all the ck's you suggested,every thing ck's good with an ohm meter and I guess it should, she is running great. I'm gonna take my spare flywheel to a machinest buddy an get him to make me a tool like RJ described to ck sensor to flywheel clearance (want it to be as good as I can get it) thanks ....RR

 

[dolluper]

Re: 1975 85 evinrude I'm lost

nice to hear it's crankin again good luck