1986 Evinrude 90HP crossflow no power

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
I've owned this motor since new and was out Sat and noticed the tach was going crazy and it was also not charging (volts remained just over 12 at all speeds). Figured it was a bad rectifier, which I replaced twice over last 31 years. As we were going at about 15 MPH, all of a sudden it felt like we hit a patch of weeds, and when I put it in neutral to check she stalled and I couldn't restart. Prop was clear and after repeated attempts to restart, coast guard offered to tow us to nearest marina. Went home and got fresh gas and battery off my other boat and finally got her started (not easily) and managed to limp home. Bench tested rectifier and although it passed current in one direction and not other per manual for each wire, readings were not the same as the spare I had. So I swapped in the spare and now tach works normal and she charges again, but she still can't rev above 2000 rpms. Besides checking resistance of stator, pulling and checking plugs, checking spark plug wire resistance, checking for spark and all the normal things, does anyone have suggestions. I know I should probably go through the entire troubleshooting flow chart stuff, but the way I figure it, the rectifier may have caused a second problem, or another issue may have caused the rectifier to get damaged, so perhaps I can narrow my search. Thanks for any wisdom anyone can offer, Jim
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Check the compression and see if it has spark to all cylinders.
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,598
Any engine overheating or water circulation issues? If you have the water cooled regulator, may have overheated (not sure how to test the thing, or would pass that along).
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
I'll check compression when I look at the plugs (haven't done so in 2 years, but it was always good and I decarb every couple of years also). Just thinking that the rectifier problem might be related somehow.
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
Its the unregulated kind, and engine did not overheat. I have both water pressure and temp gauges, and keep a close eye on both. Hope stator wasn't fried, but I'll check its resistance tomorrow.
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
Finally got a chance to do some more troubleshooting after work today. Started it up, again with difficulty, and started pulling spark plug wires to see if any pulled made any difference in how she ran. Began with starboard side, first #1 then #3. No change in idle. Then port side, #2 and she stalled immediately. I could tell it had spark in #2 because I felt a shock as I pulled the wire. Restarted her and next pulled #4- I felt shock again as doing so and she almost stalled, but hanged on. Can't believe she can run on only one cylinder, but she did. So since starboard side has no spark on either cylinder, I'm guessing it's the power pack for that side. Before I order a new one, probably should check all wiring connections to it, and if all is in order, swap it with port and see if that side then has the issue. Does anyone think this could be related to the rectifier failure that I fixed first? Could one thing have damaged the other, assuming all wiring connections were good? Thanks, Jim
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
No. The ignition and the charging systems are entirely separate.
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
Just find it strange to have two electrical failures at same time and not be related. Jim
 

Johnrudemech

Recruit
Joined
Aug 31, 2017
Messages
4
Yes swap the powerpacks and just make sure the connectors all have the pins going into their female sockets securely. On these engines the rubber connectors get old and you don't get good contact and loose spark.
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
Hi all,

I swapped the power packs (and cleaned all connections while doing so) and issue traveled to other bank. So I know she needs a new PP. I do have a couple of questions. I read somewhere that you should replace both PP's- if really true I could probably keep the old good one as a spare, but they are not inexpensive. I believe I need part# 0583110, which ranges from CDI's on eBay for $75 all the way up to $160 for BRP's. Any opinions as to quality differences, and should I really replace both?

Lastly, I read something CDI's troubleshooting guide (6th edition, page 40). It talks about no spark or intermittent spark on one cylinder or one bank. It said if the problem moves when you swap power packs, "replace the power pack that was firing correctly due to a bad blocking diode in the pack". Does this mean the one I thought was good is really the bad one, and it's interfering with the one on the other bank?

Thanks, Jim
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
I was mistaken about CDI pricing- on iBoats it can be had for about $95 with shipping, which is better than it sells for on eBay. The cheap ones on eBay I thought were CDI were really made by Arieltek (not familiar with them). CDI's look to be better quality. BRP about $141 on Amazon, and original OMC old stock about $105. I'm thinking CDI is best choice, and iBoats has best price. But should I get two and keep old working one as a spare?
 
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