83 90 hp johnson

Just bought a pontoon with a 83 90 hp Johnson outboard. I've took it out 2 times since I bought it and been stranded both times. It starts and ran fine but after going down the lake a little bit it kinda sputtered a bit and died and wouldn't start back. Any ideas? Coil?

Check for spark. It should jump a 7/16" open air gap on a tester.

Check compression also

What is the age/condition of the water pump? It's possible you're not getting good flow and the engine is overheating. Do you get a beep from the alarm when you start the engine? If not you either have a faulty alarm horn or it's been disconnected.

Do you have a water pressure gauge? On pontoons those are very helpful because you can't see the water indicator on the back of the engine. If your alarm horn is working you should get a constant alarm if the engine is over heating.

KJ

Compression is good and the water flow is good. I changed the coils out. Took it out today and at full throttle it would go full speed for a second then cut out and lose power then full speed again. If i stayed in the throttle it would die after a few seconds. It didnt do this before I changed the coils. I still havent put together the new plug wires that came with the coils. Think they could be the problem? Im about ready to sink this thing!

It could be a fuel problem. Do you use ethanol fuel? If it dies at full throttle, but stays running when you back off then it sounds like a fuel starvation issue. Let us know if these are the symptoms and then we can go from there.

I use ethanol free fuel. I got the plug wires put together and put on uesterday. Sounded a whole lot better. The wires were pretty old looking Im going to take it out this weekend and see how it does. Ill let you know. Thanks for all the suggestions.

stizz49 said:

Just bought a pontoon with a 83 90 hp Johnson outboard. I've took it out 2 times since I bought it and been stranded both times. It starts and ran fine but after going down the lake a little bit it kinda sputtered a bit and died and wouldn't start back. Any ideas? Coil?

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In agreement with Tim but I would add:

And now you know why that fellow wanted to sell it. Yeah, that's usually the case. However, anything can be fixed.

Saying the compression and spark is good is speaking in generalities and tells us nothing. We need to know exactly what the psi compression reading is on all "individual" cylinders. Standing in back of the engine, facing the spark plugs, the cylinders are numbered as:

2....1
4....3

Same scenario holds true on the spark... which should jump a 7/16" air gap with a strong blue lightning like flame... a real SNAP! Does it?. Note that the 7/16" air gap is important. Don't have a air gap tester handy at the moment?... you can substitute using a #2 philips screwdriver, stick the rip of the screwdriver into the coil spring that normally grips the spark plug top, then hold the shank of the screwdriver that distance away from the powerhead. That figure of 7/16" confuses some... think 1/2" for a setting in that case.

If any certain cylinder is not as it should be as described above.... explain what and as to what cylinder.

The spark plugs should be QL77JC4 Champion plugs, gaped at either ,030 (long life) or .040 (super hot spark). If your plugs are different, what are they? Also, what do your present s/plugs look like when removed... and do they all look alike? If they vary... how and what cylinder?

Standing in back of the engine, facing the spark plugs, Port is LEFT... Starboard is RIGHT. Best to use those terminologies as standing elsewhere, the location of left/right changes. You probably already are aware of that, but for those that don't....... now they do.

Now, when that engine cuts back on the rpms, loses power, slows down.... is that a gradual drop of power such as a automobile running out of gas... or is it a sudden instantaneous drop such as someone yanking a couple spark plugs wires off?

You sound like a very impatient fellow (ready to sink the craft already). Keep in mind that a boater must be a person of patience who is funded well enough to throw money at that hole in the water (hole = water displaced by the weight of the craft). If this is not the case, a second choice should not be an aircraft!

Agreed.-----On more than one occasion have I heard this statement from someone at the shop door.--------" I just bought this thing " and I have trouble.

The compression on all 4 were around 120 psi. I uses the 7/16 th gap test on plugs all looked good. I took it out today after putting the new wires on and it still ran the same. It ran good for a few mins then it started losing power again. Its like its dropping some cylinders not like when a cars running out of gas. But with that being said when it lost power i could pump the bulb on the fuel line and it would pick up power again. I put a new line and bulb on it last week. How do i test the stator? What should the readings be on the stator when I test it? How do I test it. It has a solid black wire and a black and yellow wire on the port end and a solid yellow a yellow and white wire and the solid black and black and white wire on the starboard end? Ive had a few people suggest test the stator is why im asking but it dont make sense to me it would run better when i pump the bulb and it be an electrical issue. Thanks again for all the imput.

If pumping the fuel primer bulb (acting as a manual fuel pump) corrects the problem.... there is a problem with the fuel pump OR a sir/fuel leak somewhere between the fuel pump and the fuel supply.

The stator is not your problem at the moment.

Test run with another tank and a good hose.

Also while checking all this out i found my rectifier was bad. Or at least im pretty sure it is since the wax looking stuff is pretty much melting off the back of it and dripping down the motor. Does this do anything besides charge the battery?

racerone said:

Test run with another tank and a good hose.

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i have 2 tanks now it ran the same with both.

Right. Follow these 2 guys and you will get it solved. My guess is since the symptoms occur at full speed, and the previous owner may have used ethanol, you will need a fuel pump. I just tuned up my little 1967 6 hp Evinrude Fisherman, with 3000 to 4000 hours trolling on it and I found an internally arcing coil when under load. Spark test was fine with a 5/16 inch crackle blue/white spark......but under load and above mid range throttle, a miss. There was no sign of the normal problem......the external arc to the stator.
But honestly I say to you, it has NEVER tasted alcohol and it has the ORIGINAL FUEL PUMP. I have owned it since new as my Dad bought it for my guiding when I was 12 years old. It has spent it's life in the remote Canadian wilderness where ethanol is not on the menu.

stizz49 said:

i have 2 tanks now it ran the same with both.

Click to expand...

BUT....... If pumping the fuel primer bulb caused the problem to cease, that leads one right into the fuel pump!

stizz49 said:

i have 2 tanks now it ran the same with both.

Click to expand...

I have a 1990 90 hp. I had a similar problem and it turned out to be warped carb bowls leaking air. Took them off and sanded them down flat and completely resolved my issue. Lots of threads on here about doing it, or probably on youtube as well.

Or replace with new metal ones.

He may want to open up the carbs and have a look see inside. Who knows what the seller did to the engine. He may have not set the float drop when he may or may not have cleaned the carbs. Who knows.

Ill try everything yall suggested. Ill keep u posted. What does the rectifier do beside charge the battery? I found that mine is bad.

It converts alternating current to direct current so your battery will charge and support your electrical accessories. Current, in other words can flow in only ONE DIRECTION through it. You can disconnect it and check it with your multimeter using the ohms setting and then reversing your leads. Results, if favorable, will show continuity in one direction but no continuity in the other direction. If your rectifier has melted then you have to determine the reason why. You should check the output of your alternator or stator which is producing the current directed through the rectifier. The input to the rectifier cannot be excessive.
Joe, can you believe it's snowing here today? 45 mph wind off lake Superior? 36 degrees! Thinking of moving to Florida......this is ridiculous.

Well i think I discovered my problem. One of the smaller fuel lines was disconnected. I cant tell exactly where it came from without removing the carb. Any advice on taking off the carbs. I started taking the intake housing off but rannout of day light. Im a little nervous taking the carb off. There alot of lines in there

Do you know how to send us a photo? Downsize to 1000 k or less. Of course take off the air intake housing first so we can see what line is off. Click on "Go Advanced", then the paper clip up above. Thanks.

I took these earlier. Ill get a better one tomorrow. One of these lines run to the top carb. The one thats off runs somewhere to the bottom. The red arrow is the one thats off.

Thanks for telling me how to post pictures too. I couldnt figure that out Ill take some picture u can actually see tomorrow.

That hose

Okay good we will wait for that. My picture is my very first outboard mentioned in post #15. It has been my guide motor for over 50 years. Still has the original fuel pump, primer bulb, head gasket, and never even a carb cleaning needed.

I went ahead and pulled the carbd so i could find where the line went and i found it. What do you recommend to use ro clean the carbs with. The gaskets look good. They ok to put back on or should i order some new ones

Those wee hoses have to do with the electric primer for starting the motor.-----There are also wee hoses for the oil recirculation / bleed system.-----If previous owner left them off then what else was forgotten ?--Check the fuel pump diaphragm or install a new diaphragm as they are about $5.00------Check the check valves in the pump too.-The fuel pump is driven by a positive pressure pulse from the crankcase.----There may be issues there.----That one little hose would not be your problem.----The bore of the hose is very small and can not pass much fuel or air.----Did the hose go to a fitting in the manifold ?----On a " new to you motor " a new water pump impeller is almost a must do.----Or at least check that the overheat horn is in fact in working order.

Ive ordered a new fuel pump. The hose broke off the end was still in the fitting in the manifold