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Johnson 90HP No Spark

J

jdiehl

New member
Hi,
I am new to the site and have been searching through to find some answers to my issue. At this point I have not found any that match exactly what I am getting so hopefully someone can assist. Thank you in advance for any help you can give. Now with the issue. I have a 90HP Johnson SPL Model #J90TSLEUA says 1996 on the tag on the motor though from all I can find and have talked to already it is actually a 1997 model. At this point this is what happened. I was going across the lake at about 25mph and started to slow down on the throttle and all of a sudden the motor died and though it would turn over it would not fire. Got back home and next day started troubleshooting it. Tested coil packs with volt meter and the all read around .544 or so and from what I can see on the CDI site they should be .500 give or take. So I then checked for spark,etc and found no spark still. Checked the fuse in the system 20amp and it is good. Verified that with the kill switch disconnected I do not have any spark and the with the yellow wires off of the rectifier and no spark. I checked the rectifier and found it appears to be working as should from what volt meter indicates (reading one way and not the other). I then went ahead and checked the power pack connections and some seemed correct though one did not which was the brown wire to brown yellow wire. I got an open and from what I read on the CDI site help it was supposed to be 450-650ohms. So I bought a new power pack. Put it on and attempted to start and still no spark. I then decided to go ahead and try another battery just in-case the first one or two did not correct the issues. Put battery on and turned over motor and it seemed to fire three times though did not start. Waited about 1/2 hr and then attempted again and now nothing again and from what I can tell no spark again. Anyone got any other tips to check. I am going to attempt to go through the checks again from the CDI help log though want to see if anyone has more things to check. Oh ya also I found that while cranking it over if I push forward on the throttle while still in neutral the circuit stopped cranking, maybe this is part of the issue? Thanks again for anyone that can help me with further testing on this.
Thanks,
Jeremy
 
the pushing forward in neutral is just causing your safety interlock switch to break contact...thats not your problem..the rectifier has nothing to do with starting or the running of the engine...you gave eliminated the kill switch circuit by removing the wire from the inline connector..here is what you have left..the engine must turn 350 rpm's to fire..the stator puts out ac to the power pack..the timer base tells it when to fire...simple as that...go back to your cdi trouble shooting guide and test the stator and timer base as per instructed...i would do the resistance checks first...also look up under flywheel and see if you have any indications of stator meltdown such as black drippings..
 
Papyson,
Thank you for the tip, I hope to get to this today after work to see what I find. I'll update then with information.
 
Papyson,
I checked this tonight with some more of the CDI help and I am not sure I am doing everything correct or maybe the CDI tests I have are the wrong ones. Anyhow with the power pack hooked up and key switch on I checked the brown to brown/yellow through the back and it gives me 303 ohms (from what I read from CDI the OEM should read 510-650ohms), I then disconnected the pack and checked the stator and it still reads 303 ohms from the stator wires ( question is though it says to check the stator brown to brown/yellow and the wires are brown/black and brown/white which I am guessing is just the stator wires being different. So am I reading the paper correct and thus the stator is bad which is causing my issue with not charging the battery when firing so therefore the RPM's are not getting up fast enough to allow the system to fire? Would explain the battery I changed out and it fired a few times then just cranks over and not spark? I also found the battery I put in place only has 650 CCA and from what I read I need one that does 850 CCA. Possible why it fired like I said and now the motor is pulling to much juice and stator not allowing it to spin at the needed 250+ RPM's to start.
Also I tested my old power pack again and found that one of the checks from the main harness to the coil wires was intermittent on the reading and all the others were fine. So I believe the pack wire was bad also. I thank you for your help and look forward to hearing if I am getting the correct info and troubleshooting info.
Thanks again,
Jeremy
 
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The stator is not pulling juice to keep you from turning enough rpm...stators generate power in conjunction with magnets to feed your power pack...same with the charging circuit which is not in the picture til the engine starts...assuming your readings are correct the stator reads low.....but i dont think you are ready for a stator yet....i would put a new battery on it and get it turning over at a minimum of 350 rpm....it takes proper rpm for the stator and timer base to fire the power pack...
 
Ok so at this point I was able to do further checks and still not getting this to start. I put in a brand new battery which is 1000 CCA. It definitely had a battery issue before as it is cranking at a rapid pace now so sure it is the 350rpm's or more. This is what is weird about this though when I installed the new battery and turned it over it fired three times like before and then it stopped firing again. I since have also talked to the local marine guy which used to be a Johnson dealer for around 20years and he told me he though it was the rectifier after what I have replaced and done. They didn't have one so I had to get one. I put it on and nothing still firing. I asked them about the plugs to see if they though they may all be fouled to a point where they will not fire though he said that really would not be the case. Do you have anything further for me to attempt. Do you think I may have a faulty power pack? It all checks fine though at this point. Do you think that a coil pack could be causing the issue here? I am at a loss at this point and just want to get it running. Last resort will be to put i on the trailer this week and see what can be done before I put it in storage. ??? Thanks again for helping with this!
 
Thank you I will check further with this I though maybe cables for the battery though after several checks I think they are good though it could be the issue. Also I did check the cables to the starter. Maybe I need to remove the starter and check all the connections and recheck everything again and see what happens. Battery is new now 1000CCA!
 
papyson said:
The stator is not pulling juice to keep you from turning enough rpm...stators generate power in conjunction with magnets to feed your power pack...same with the charging circuit which is not in the picture til the engine starts...assuming your readings are correct the stator reads low.....but i dont think you are ready for a stator yet....i would put a new battery on it and get it turning over at a minimum of 350 rpm....it takes proper rpm for the stator and timer base to fire the power pack...
Click to expand...
why would my 90 hp start fine and when im at full throttle it will run great for a while and then fall on its face but still run about half power.
 
jdiehl....... If it was mentioned one way or the other through the above posts, I missed it. Anyhow.... in doing a spark test, the spark plugs "must" be removed in order to obtain the highest rpm available. So... if you haven't removed them, do so.

The black/yellow wire at the "M" terminal of the ignition switch.... temporarily disconnect it (Kill circuit). Now do the spark test. If you have spark with that wire disconnected but no spark with it connected, you have a internal short within the ignition switch, in which case, replace it.

BTW.... 90TSLEUA = 1997, not 1996... OMC's code is the word INTRODUCES whereas each letter stands for a number. The "EU" in the model number would be E=9...U=7... The number 19 is taken for granted = 1997
 
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