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1978 75 hp Evinrude firing issue

airboat233

airboat233

Member
Hello forum, new member here in hope of resolveing an issue. I have had a 1978 three cylinder Evinrude on a pontoon boat riged for spec fishing for near twenty years. Had a problem two years ago with it firing on all cylinders. As that day started out everything was fine. As I cranked up to leave, engine cranked right up. As I tried to accelerate, the engine would only run at idle. I idled back to ramp and went home. I tried for a few days to figure out, but never did. About the only thing I new to try was this... Had one cyl firing two were not (engine will crank and idle like nothing is wrong). By process of swaping around plugs and so forth I found that those two cyl could not be made to fire. So i guess ever what it is that tells the coil to work is bad. I have put the coil that does fire on the cylinders that do not fire and they still do not fire. Engine has sat for two years due to other issues. But now I hope to find someone to help point me in the right direction and get this boat on the water. Thanks and Sorry for the long post. airboat233
 
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First thing to do is check the compression. Second, clean the carbs and the fuel system. Third, go to cdielectronics for trouble shooting procedures on the ignition system. And don't forget the gear case oil and the water pump.
 
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Hello and thanks for the responce. However compression has nothing to do with engine fire,, with starting and performance a big YES, nor do the carbs. An engine will fire with zero compression and with no carbs bolted to the engine.Third the water pump and gear oil,, well I dont think they do either. All tho, I had planned to perform those tasks after I had all three cylinders firing. As I said in my post the engine will crank and idle with no problem. Which actually sounds ok even tho the engine is running only on ONE cylinder. Lastly, the cdi system is why I posted. Knowing that the cdi is directily the cause of my issue. In short out of three cylinders, ONE fires super, Two cylinders have no fire at all. Thanks Boobie for the reply and I guess I was not clear enough in my post. Sorry and maybe my reply will help clarify to others. Have a super day. airboat233 Anyone else out there for help?
 
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No problem Boobie. All things aside tho I dont think I can post agin. I guess I can try agin right here. HELLO OUT THERE. I have a 1978 evinrude 75 hp. Has three cylinders. One cylinder fires good. Two cylinders do not fire. Engine will crank and run on the one cylinder. How do I trouble shoot the cdi. I have tried swaping the good coil to both cylinders not firing and same thing,, no fire. I have a volt,,ohm meter, spark tester for all three cylinders plus a circuit tester. I am able to use these corectly. What I need is a walk thru for a dummy on the cdi to find what is not letting the coil fire. Im just guessing is got to be somethng in the harness between the engine and coils. Somethng not saying OK coil you can throw the lighting bolt now. Anyone in the forum that can help? Thanks airboat233. Off topic,, forum has given me five post to check which I did. Why send someone to a post for help and the posts never solved the OP issue? go figure
 
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racerone said:
I guess you just need to do some trouble shooting on the spark system.
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Hi racerone, no kidding. With due respect, why do you think Im here? I will say why. Im am looking for help from someone to walk me thru the harness from the stator to the coil to to find what is only letting One of three coils to fire. Anyone? airboat233
 
Always check the compression and the fire with a gap tester first when trouble shooting...then your decision is it a fuel or fire problem...you have decided its a fire problem...however if the compression is bad you are pissing into the wind...plus you can count on a complete carb job if the motor has set for two years....
 
Go to cdielectronics.com for trouble shooting procedures on the ignition system. Just to warn you, you'll need a DVA adapter.
 
Old rule of thumb back in those days. If you had no spark on one cylinder but spark on another it was either a power pack, coil or sensor.
 
papyson said:
Always check the compression and the fire with a gap tester first when trouble shooting...then your decision is it a fuel or fire problem...you have decided its a fire problem...however if the compression is bad you are pissing into the wind...plus you can count on a complete carb job if the motor has set for two years....
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Hello papyson, thanks for reply. I guess I have not made myself very clear in my post. First before I posted I read somewhere on here about posting which ask the poster to add some history into the post (My first mistake). If I could start over.........I am capible of building an automotive engine, but just the engine without electronics. I know full well how a combustion engine works. However I am not a tech in electronics. Also I have never done any mechanical work on a marine engine except for the following,,, rebuilding carbs, changing water pumps, rebuild fuel pumps, prop work, starter rebuilds. Just the small stuff. I do belive I would have no problem rebuilding the entire mechanical aspect of a marine engine given I had the special tools and shop manual. Now back to asking for some help on this forum. I have very,,, very,,, little knowledge of the electronic side of it. I am very old school, points and so forth. I know what it takes for an engine to run as far as, fuel, spark, and O2. Now I do know this, I have seen a lot of any kind of engine running Slam Blown Up. Point being there is,,An engine does not have to have compression to fire. Thats what I am looking for,, "FIRE to the sparkplug" My outboard engine in question now will crank and run till it runs out of gas but only on one cylinder. I need to get two more cylinders to fire. I have checked all three cylinders with a spark tester. My problem lies in the cdi harness (I Think) somewhere between the stator and the coil. I have the tools to check,,,,,, but what, what?, where,?. Thats what I need help with. Someone has allready sent me to a site for help and they want to sell me a shop manual. That is not the kind of help I need. I dont know,, but maybe thats the way this forum works. If so my second mistake. Which means I need to look elsewhere. I dont know,,,,,yet. I hope this makes more since now. Agin thanks for both replies, and the answer about the stator. Which tells me that after the stator there must be three things that can go bad that will stop fire to the plug. One for each coil. Just guessing. airboat233
 
Boobie said:
Go to cdielectronics.com for trouble shooting procedures on the ignition system. Just to warn you, you'll need a DVA adapter.
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Thanks boobie, I checked out the DVA and I dont have a meter or an adapter. This will stop me from fixing my problem. Ill just have to do something different. Thanks agin for more or less the answer to my post. To anyone else that reads this,,,, my question has been answered. I consider this post closed. Thanks to all airboat 233
 
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had the volt ohm meter but not the DVA. I think most folks have a volt ohm, But how many wil have the DVA?. I had closed the post the best I could. Maybe start a new one to let others know you have the answer but aint gonna tell anyone untill one waste 3 phqueing days to tell um
 
???????????????--------------Why are you asking for help with your motor.-----------You seem very quailified to fix your motor without help.
 
racerone said:
???????????????--------------Why are you asking for help with your motor.-----------You seem very quailified to fix your motor without help.
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As I have allready stated, I am guessing the problem,, thru reasearch the problem is in the cdi electronic harness. Which in guessing could be a number of different parts. The only parts I have eliminated is the plugs and coils. I did this because I have one cyl working. I swaped the coil from the working cyl to a cyl without fire and still no fire. I also took a coil from a cyl not firing and put it on cyl that was working and had fire. Telling me all three coils were good. Help is needed because I do not know what else it could be or how to check. I am use to automotive and aircraft engines with stand alone ingnition such as MSD. All I know is,, there are other parts in the cdi that can be bad, but where, what and how to check. I thought someone on this forum could guide me thru it. All I seem to get here is,, check the compression. Knowing,, sure you need compression, but not to have spark. I did check spark with a spark gap tester, all three cylinders at once. Have one cyl jump 1/2 inch, two cyls none, no spark. This is the very best I can explain my issue. I will say one more time,,,this engine will start very fast and idle on the one cylinder under a load. airboat233, (ps it may be because i'm 67 years old, wink) another ps.....(I have a engine not a motor but do have a starter motor. wink agin)
 
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Well you won't spend the money on a DVA tester to do the trouble shooting properly so you "might" as well start guessing.
 
Boobie said:
Well you won't spend the money on a DVA tester to do the trouble shooting properly so you "might" as well start guessing.
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Hey boobie, do me a favor and go bother someone else. I dont need any help from you what so ever. Am asking you to not reply to this post or any of my future post. I have enough to deal with , without your B.S. thanks
 
kimcrwbr1 said:
The cost of new parts and the possibility you may burn up a new part without proper diagnostic. There is no way to test a powerpack you need to confirm the other parts are good then the powerpack/switchbox is is probably the problem. It sounds like the coils are good. Do you have a good wiring diagram I like to tesst all the wires are going where they are supposed to and test every wire for a shorts. once you know all the wires are good then you can start checking ohms and DVA voltages to isolate the fault/s. The $30 for a DVA is money well spent in both parts and dependability out on the water.
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Thanks, I would rather find out what is bad so i'll have a DVA meter here today. I also now have in front of me a Clymer evinrude/Johnson shop manual which does cover my engine. Now if I can understand it. WLUK airboat233
 
kimcrwbr1 said:
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-173-1235.pdf
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-113-1726.pdf
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-153-3408.pdf
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-193-3408.pdf
http://www.cdielectronics.com/wp-content/uploads/2013/09/IS-183-2303.pdf
Maybe you can find the problem read through these all the way my guess would be the trigger or the switchbox. if you get spark the stator is likely good.
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Another thanks kimcrwbr!, with the help you have given me I think I have a chance in fixing my issue. thanks and I'll be back and let you know. airboat233
 
Thanks Kimcrwbr1 for all the help and direction. My issue is now "fixed". I now can make that last spec fishing trip.(cancer). Sensor coils in timer base. I would like to relate to you tho that in my shop manual printed in 1990 made no mention of a DVA METER anywhere. It did mention a neon light switch what ever that is. I now will ck wheel bearings, generator, ligths, ect.. Then head to water for about three weeks. 24 ft pontoon, all home made. Small cabin sleeps two, A/C, generator, shower, two foot controlled trolling motors, frig, and stove. Cant say thanks enough. airboat233, oh yea, happy up coming holidays and a super good 2013!
 

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