1994 johnson 40 hp...got me stumped

Recently got a 15 foot Lowe boat with a 94 40 hp Johnson outboard on it. My dad had the carb's cleaned out before I got it from him and it would start fine in the yard with some muffs. All is well the first time we put it in the water until I bring it back home, and then it will not start on the muffs again. I changed the plugs b/c they were already fouled. Replaced them with NGK which didn't work long before they were fouled. Now I have the factory Champion Plugs in there and it has started in the yard everyday on the muffs but today. It has been about 2 weeks with the new plugs, which is about the time frame I had the old plugs in before they were fouled. Any ideas on what I can try before I take it to someone? I'm located in Gville SC in case anyone knows of a decent shop that could help me out also!

Re: 1994 johnson 40 hp...got me stumped

First off, welcome to iboats.Sounds like it is running rich. Are you mixing your gas and oil yourself? Stay with the Champion plugs.

Re: 1994 johnson 40 hp...got me stumped

Thanks for the welcome. Its nice to find this site, which seems like it gives excellent help for boaters. Well I took a look at the carbs to make sure they were adjusted. They are now fully horizontal at WOT and closed at idle. I started the motor on muffs yesterday and then put it in a barrell to see how it would react. It started smoothly and ran good at idle. This morning I put it back in the barrell (it was cold this time and had not been started yet) and it had problems starting. Actually it never started, only acted like it wanted too, but never stayed on. As soon as I took it out the barrell and put the muffs back on, it started right up. I'm guessing I will try the compression next. I'd rather test everything, that to start throwing parts on it. I will let you know what I find with the test.

Re: 1994 johnson 40 hp...got me stumped

Compression test is a good idea. If you aren't getting compression you aren't getting combustion. when you pulled the plugs there wasn't any milky white goo on them was there?

Re: 1994 johnson 40 hp...got me stumped

Didn't see any milky residue on the plugs fireman. They weren't clean, but definitely no white stuff.

Re: 1994 johnson 40 hp...got me stumped

The compression was about 139 in the first cylinder and 141 in the second cylinder. I did see one thing I was confused about. When I put the muffs on it and run, I just have water coming out of the water pump indicator which is normal. But when I put the motor in the barrell and start it, water comes out of the pump indicator and also I believe the exhaust. I'm going to go with exhaust because it blows blue smoke out when started. But after it runs awhile, water beings to spew out also. Is this normal?

Re: 1994 johnson 40 hp...got me stumped

Next time it won't start do a spark check immediately with a gap tester. I have a 95, 40 HP and had no end of problems getting it to start consistently. Eventually I found the power pack was bad and wouldn't work if it was cold. If warm it worked fine. Changed it out and haven't had a problem since (knock on wood). Very nice compression numbers. I am not sure about your water/exhaust question. I think once the stat opens you should expect to see water there but I am really unsure of myself on this one. Best of luck.

Re: 1994 johnson 40 hp...got me stumped

Thanks Rick. I will keep that in mind next time I try to start it and it doesn't start. From what I found browsing the net after I typed my last post, water should come out of that exhaust port at idle. So hopefully that is a good thing. My dad was thinking it may be the powerpack while I was talking to him, but I didn't want to jump to conclusions if that wasn't the problem. Because as you said as long as its warm it will start up quickly. But if its cold, then its almost impossible to start.

Re: 1994 johnson 40 hp...got me stumped

The exhaust situation is normal. If your plugs are sooty that means that it is firing but running rich. If they are just blackish and wet then you might not have any spark.

Re: 1994 johnson 40 hp...got me stumped

Is there any way to check the ignition coil or the spark plug wires to cross those two off the list of possible problems? Besides waiting for it not to start one day then trying to check the spark is there anything else I can do in the time being to narrow down the problem?

Re: 1994 johnson 40 hp...got me stumped

Have you checked your spark yet? These engines will run on one cylinder. If you don't have spark on one cylinder then physically swap the coils and check again. That will tell you if you have a bad coil.

Re: 1994 johnson 40 hp...got me stumped

Just checked the spark coming from both coils. Had a nice blue spark both times. I checked the spark last week sometime when I first installd the Champion plugs and remember getting a shock from the plug boot as my wife turned the engine over. This time, that shock didn't occur. So I'm not sure if I was holding it different or just a coincidence. I'll try to start it tomorrow and let it sit overnight.

Re: 1994 johnson 40 hp...got me stumped

I assume that you used a spark tester for this. It has to jump 7/16" and bright blue with a snap to it. A cheap spark tester will just show that you have spark. it could be a weak yellow spark if you can't make it jump that gap.

Re: 1994 johnson 40 hp...got me stumped

Loweboater,
I live in Spartanburg, off Ashville Highway, and my dad had to have someone look at his 90 horse Evinrude and my dad is very picky on who he uses but if you need someone that you can trust I can ask my dad who he took it too and let you know. Basically I found my dad a 90 Horse V-4, 1998 year model for, can you believe it $55.00 a few weeks ago, the guy that had it did not know what he had and said the previous owner of the house left it there, and my dad also found a good used boat to hang that outboard on and we tried to get it to crank over but couldn't get spark to the plugs so my dad knows an outboard mechanic that is very good and has the test equipment to diagnose what is going on he found that there was 2 bad ignition coils and the wiring harness had to be replaced and said all we have to do is clean the carbs, which we can do, change out the water pump impeller, which we can do, the thermostats, gear lube, and we will be good to go. Like I said, we are wanting to do everything on the motor and the boat to see if we can do it, which I know we can, and save money restoring the boat and motor but when we hung the outboard on the boat and try to fire it off we did not get spark at the plugs and we messed with it for a while and gave up. So that is the only reason why we took the outboard to the mechanic so he can give us an honest assessment of the outboard and he said that it is a good one. So let me know if you need that outboard mechanics name and phone number and I will PM you. Like i said I live in Spartanburg which is about 30 minutes away from Greenville going down Interstate 85.

Re: 1994 johnson 40 hp...got me stumped

loweboater said:

Thanks Rick. I will keep that in mind next time I try to start it and it doesn't start. From what I found browsing the net after I typed my last post, water should come out of that exhaust port at idle. So hopefully that is a good thing. My dad was thinking it may be the powerpack while I was talking to him, but I didn't want to jump to conclusions if that wasn't the problem. Because as you said as long as its warm it will start up quickly. But if its cold, then its almost impossible to start.

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Once fired mine would fire every time for the rest of the day and sometimes even the next day. But leave it for a week and I had to crank and crank and many times limp away from the ramp with my trusty 4 HP. Once the weather got really cold it would not start at all no matter how much I cranked. The power pack is expensive so I would suggest you take it to someone familiar with testing your ignition system. The parts are too expensive to guess. Having said that it is an easy part to replace on your own, but get someone knowledgeable to prove which part is at fault. Rick.

Re: 1994 johnson 40 hp...got me stumped

I definitely agree with you Rick on parts being too expensive to just guess and replace. I don't have a problem trying to figure out whats wrong with the boat, but I'm hoping that I can a definitive answer with my tests before I buy anything. If not, then I will have to take it to someone for further testing. Can the power pack be tested with a voltmeter or something of that nature? Or would it be wise to just go ahead and take it to someone with knowledge?

Re: 1994 johnson 40 hp...got me stumped

you can test them with a DVA meter. CDI has a trouble shooting website then literally is step by step. Google CDI troubleshooting. Someone posted the address on here but I can't find it right now.
http://www.cdielectronics.com/Support.aspx. Never mind. found it in my bookmarks.

Re: 1994 johnson 40 hp...got me stumped

loweboater said:

I definitely agree with you Rick on parts being too expensive to just guess and replace. I don't have a problem trying to figure out whats wrong with the boat, but I'm hoping that I can a definitive answer with my tests before I buy anything. If not, then I will have to take it to someone for further testing. Can the power pack be tested with a voltmeter or something of that nature? Or would it be wise to just go ahead and take it to someone with knowledge?

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DVA for the pawer pack is required. You can check the coils for resistance with a multi meter which I did. They were outside of CDI spec. by a lot so I took them to a shop to get replacements. The mechanic tested them and said they were fine and that temperature alone can make a difference to the ohm readings. That's when I decided to leave the CDI testing to the experts. I have since bought a DVA meter but am hoping I never get to use it. LOL. Rick.

Re: 1994 johnson 40 hp...got me stumped

Thank you guys for all this quick information! I went outisde today and turned the motor over once, but it didnt start. So I pushed the choke down for 8-10 seconds and then started the engine. It ran fine, and restarted once I turned it off. I will keep trying this at different times during this coming week to see exactly what she does. The boat was in the barrell this morning when it satrted which is a good sign I do believe.

Re: 1994 johnson 40 hp...got me stumped

One ?'s
are you still running the VRO.

if you are this could be the root problem. Pull the fuel line from the top of the VRO pump. pump the bulb if it's full of oil than it's over oiling and causing a hard start. One of three ways to fix. replace VRO. Bypass the oil side of the VRO by mixing fuel, and only using the fuel pump side of the VRO. Or switching the VRO out with pulse driven fuel pump