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Small outboard motor trouble

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gundy1212

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Hey guys, I own a 15hp 1990 Johnson 2 stroke outboard motor, and I have been having trouble. I posted before about this, but I have a few updates. This motor is hard to get going, as in takes a lot of pulls. When I pull it, it starts and dies a couple of times before I can get it to stay alive. When I stop the engine, it doesn’t want to start back up for a few minutes. Also, it doesn’t pee. The engine doesn’t feel like it’s overheating, and the impeller is all good. I don’t know what is going on with this thing. Could it be the carburetor or adjustments or what? And when I get it running, it can accelerate great and idle. I just don’t know.
 
Nobody can see or touch your motor !----How did it run for you last season?-----Post the actual compression values.----Does spark jump a gap of 3/8" on both leads ?---Does primer bulb work and go firm.----Does choke flapper close and stay closed during starting ?-----Provide the information / answers.
 
Please read and answer the question !----Does spark jump a gap of 3/8" ?----There is no mention of the sparkplug gap on the question.----Primer bulb must go hard !----If not there is a leak.----I believe this motor is an easy fix for the right person.----I think I have to step aside here.
 
Sorry if I do misunderstand. I did gap them, I read the repair manual, found the gap, and respaced them. Sorry I didn’t remember what measurement it was.
 
One last try.----The ignition system on your motor can jump a gap in air that is 10X bigger than the sparkplug gap.----So does spark jump a gap of 3/8" on both leads , yes or no ?
 
Racer is not referring to gapping the actual spark plug. He’s asking if the spark will jump an air gap of 3/8”.
Make, or buy, (about $10), a spark tester out of a few scraps, like this. You can use any method to hold the wires, hot glue gun, a short bit of wood or metal with a screw through it etc.
Plug one wire into the sparkplug boot,ground the other to the motor block. Space the wire ends at 3/8”, don’t worry about being exact, it should jump the gap with a hot blue/white spark.
 

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Okay with that said I will add a few more thoughts.
Sometimes the choke doesn't close all the way on these and that will make it hard starting especially with the throttle position restriction when you are using the pull rope. It is not, in my opinion, engineered properly to allow enough throttle for starting in many conditions typically in the cold. As a veteran repairman and familiar with these motors since they came out in the mid 70's, I often make some mild modifications to allow a little more throttle when starting them. As far as the lack of water coming out the pee hole I would suggest cleaning out that tube and possibly you may find a blockage at one end or the other. Also check the thermostat as long as you're thinking about it and make sure things are clean and the thermostat will begin opening at about 140° when you put it in hot water.
 
gundy1212 said:
Hey guys, I own a 15hp 1990 Johnson 2 stroke outboard motor......it doesn’t pee. The engine doesn’t feel like it’s overheating, and the impeller is all good.......
Click to expand...
#1 How are you running the engine when you say it doesn't pee? Is this in a barrel, on a set of muffs, or with the boat floating on the lake? If it's on muffs, you need to have the hose on full blast. If this is in a barrel, the water level needs to be about 3" or more ABOVE the anti-ventilation plate for the water pump to properly self-prime.

First, run a thin wire through your water indicator hose then try again. Little critters like to make homes in there and will block flow. A second option is blow compressed air through the hose to make sure it's clear.

If you've verified the hose is clear, you're getting the correct water source to the impeller, and you still don't get flow through the pee hose, then you need to dive deeper. If you've recently replaced the impeller, make sure you got the water tube properly aligned with the pump housing. If that is good, then you need to look at Part # 330426 - Upper Water Tube Grommet that is on the Exhaust Housing Parts Diagram. These grommets are known to swell or fold over with age and restrict water flow from the pump to the engine block. If this is your problem, the power head must be removed to access the grommet and replace.

KJ
 
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