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johnson 20


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I have a 1989 johnsonn 20 outboard that pisses me off for the last two weeks.


This motor has been sitting for 3 years without running. A few weeks ago we decided to give it a spin. We used the old fuel that was almost as old as the motor had been sitting, 3 years. We went to lake simcoe, and after some time we managed to launch the boat. After that it was some trouble and time before we got er going. It would idle so slow that it would quit. It ran ok otherwise. Next day I made new fuel and went to lake simcoe again. This time it would idle properly and ran very well. Ok, now that its going well we took it to moon river to go camping. Started as before, lots of cranking. Idled well, but when I went past 1/4 power, it would cut in and out as if it tried to jump off the boat. It sounded like it was turning on and off. anyway, the campsite was not far from the marina so we got there somehow. sometimes i could run full power for a minute or soThen i noticed that a screw was filled over with silicone and the silicone came off. so i put tape over the screw and it ran very well at full power. when i came home, replaced the tape with epoxy. I thought that was the fix. :) I was mistaking :( . same symptoms as before :envy: . tried carb cleaner with no luck. before at times i could run full power but now i cant.



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Was the gas tank vented ?

Could be lots of things happening here . Ethanol coukd have settled into the carb and you have dirty jets, needle valve or gummed up carb . The only way is to do a disassemble on the carb. Your gaskets could be all dried out and causing an air leak .

Like I said lots of possibilities , a motor that sets for that long is sure to be problematic

Good luck .


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the fuel tank was vented. i just took apart the carb and sprayed it with carb cleaner aka crud buster, though it was very clean and nothing was clogged. there is only one screw, is it the idle or high speed? the gaskets were all good

Edited by seahorse
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What is the screw you referred to that you said was filled with silicone and then you filled it with epoxy. Is it a screw hole? I wouldn't think silicon or epoxy was originally intended there. You might want to find out what is supposed to be there. Maybe it is an adjustment screw or a place where a jet should be installed.

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I know you said you used carb cleaner but have you tried running a can of Sea Foam through the carburator? I think the fact that the motor sat for 3 years combined with putting probable bad gas in it (even with stabilizer added 1 year is considered by many to be the longest to keep it and that is non-ethanol gas). I would be considering having the carburator rebuilt and taking the motor to a capable mechanic to evaluate....certainly cheaper than buying a new one. I can relate to your frustration though as both my main motor and brand new kicker are in for servicing.

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yes the screw was epoxied over. It was not worn, and the carb was quite clear. that was the only screw in that carb.

when I last ran the engine, I tried to run high speed while pushing on the primer bulb hard with my foot. It did not help a bit. the primer bulb will pump fuel and develop pressure.

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A 1989 engine has pre-ethanol hoses. First thing you should do is replace all the hoses with ethanol resistant ones from the tank all the way to the carburetor. The ethanol will slowly dissolve the rubber and small pieces find their way into the carburetor and cause trouble if they get stuck in the small passages. Next you should make sure that the carburetor is clean.After 3 years of sitting you probably have sedimentation in your tank and the ethanol loosens all the junk in the tank allowing it to travel to the engine. You can fix that by getting a handful of roofing nails in the tank and a quart of lacquer thinner to go with it. let the stuff sit for a few hours and then shake the tank vigorously. The roofing nails will loosen up all the crap and then you can dispose of the junk. Only then, refill with fuel.

Underneath, I copied a fac post from I-Boats with all the info you need


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Awakening a sleeping outboard; by BoatBuoy
July 17th, 2005, 12:11 PM
Awakening a Sleeping Outboard
Frequently Asked Question (FAQ): I got this motor and it hasn’t been run in several years. What do I need to do to get it going?

I see a lot of posts from folks who have a motor that has been in storage, belonged to their dad or granddad, or for another reason, hasn’t been started for quite some time. It occurred to me that this would be a good topic for a FAQ. I recently went through most of these steps myself in preparing a motor which hadn’t been used for 15 years. Following is an attempt to provide a concise list of steps, an expanded bullet-list if you will, that have been suggested by the many experts on this forum to prepare that motor for the water.

First get yourself a manual, there is a ton of help on this board but to be fair, and so that you can learn, a reference book is a must. They can be found for sale on many sites, a few of which are kencook.com, ***************** theoutboardwizard.bizhosting.com, maxrules.com, and iboats.com. Although some folks use Seloc or Clymer manuals, they cover a range of engines and sometimes details are omitted. The reprints of the original OMC manuals are the most specific to your particular engine. Get one of them.

If any steps prove challenging or if there are questions about any of the processes, post a question in the applicable forum here at iboats using the red "search" selection at the top of each forum. You will receive an answer from one or more of the many experienced veterans here.

Let’s get started.

Lower Unit – Remove the prop and any fishing line that may be tangled, wound around the prop shaft. If the shaft is splined, apply a coat of marine bearing grease to it before re-installing the prop. If an inspection of the prop indicates any damage that could cause a vibration or imbalance, replace it or have it repaired. The rubber bushing securing the hub to the prop itself may also need replacing, but that probably cannot be determined until boat-tested.

Remove the drain screw (bottom) from the lower unit and observe the quality of the lube as it exits. If it is milky, there has been water intrusion. If you observe metal shards, there may be gear damage requiring a re-build of the lower unit. If it is empty, there may be other problems. Remove the vent screw (top screw) to allow complete draining. If none of the above mentioned situations exists, fill with lube from the bottom screw hole until lube emerges from the vent hole. Lube should be available from any oil outlet and labeled as suitable for outboard lower units.

Note: Electric shift lower units require different lube than manual shift units. Check your manual.

After unit has been filled, replace vent screw using an appropriate new screw-head gasket. Then do the same for the fill screw, trying to prevent as little loss of lube as possible.

Water Pump – Using your manual as a reference, replace the water pump – if not the complete pump, by all means replace the rubber impeller. This is absolutely necessary on motors of unknown history or on motors that haven’t had a new one in a couple of years. Before re-assembling mid-section (lower leg), see next step.

Cylinder Walls – If not already, lay the motor so the sparkplugs are up. Remove them and put in a few squirts from an oil can filled with TCW-3 oil. Move the engine around so that the oil will contact cylinder walls. Allow it to soak for a day or two. By hand, rotate the flywheel a couple of times. If it resists rotating, allow to soak longer. When flywheel finally rotates freely, install new sparkplugs.

Spark – Pull the plug wires from the sparkplugs. Your spark should jump a minimum of a 3/8" gap with a hot thick spark. If it doesn’t, you need maintenance on the ignition system. Check the sparkplug cables for cracked insulation. Otherwise, the needed maintenance will be determined by type and year of motor you’re working on. Refer to your manual. Replace the spark plugs with the manufacturer's recommended plugs, keeping the old ones as spares.

Wiring – Check all engine wiring for brittle insulation or fraying. This would necessitate re-wiring or installation of a new wiring harness.

Lubrication – Lube all moving parts including throttle linkage (white lithium) and steering shaft (chassis lube is OK).

Carburetors – Remove and disassemble carburetor(s). Soak in carb. cleaner or spray with aerosol carb. cleaner, paying particular attention to all small passages and fuel-ways. Blow dry with compressed air, again, paying particular attention to internal passages. Reassemble using an appropriate carburetor rebuild kit. If kit doesn't include a new needle and seat, get one. If the float is cork, replace it with a plastic one. Some kits include them. If the float is plastic, make sure the integrity has not been compromised. Re-install and link and sync according to your manual. Replace all under-cowl fuel lines.

Fuel pump – Using your manual as reference, remove fuel pump and clean metal parts with carb. cleaner. Install a new fuel pump kit, or replace fuel pump entirely. Replace fuel filter and any vacuum hoses that may be connected.

Fuel tank – Replace the fuel line along with the squeeze bulb (OEM bulb preferred). Note: on dual-line tank, there is no squeeze bulb. Drain fuel tank. With a flashlight, inspect for dirt, debris, or rust. If OK, rinse and refill with correct fuel/oil mix. If there are quick release connectors on the fuel lines, check the small o-rings at either end. Replace if necessary.

Controls - If remote control, check throttle and gearshift cables for proper operation. Mine were frayed and rusted and had to be replaced.

Carburetor Adjustment - For Johnson, Evinrude and Gayle motors with a low speed needle or a low and high speed needle, see the FAQ by Joe Reeves, "Carb Needle Valve Adjustment for Assorted Carb Variations".
Last edited by tashasdaddy; April 23rd, 2009, 07:21 AM.
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Edited by rolmops
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  • 8 months later...

took it to the techie, he said it was the coil. replaced the coil with no progress. took apart and cleaned the carb and that did not help. used seafoam, but that did not help. turned the carb adjustment screw, even at smoking rich or any other setting it did not run. inspected the wiring for shorts with a multi meter, all wires are OK. now what do I do? the timing is not adjustable so it could not get messed up. on one cylinder connected the other disconnected it works OK at all speeds, two cylinders not OK. on the other cylinder separate it doesn't even try to start. HELP:thinking::thinking::thinking: i can post a video later on.

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We'll start from scratch. Do you have spark on both plugs? Do you have good compression on cylinders like within 5-10 of each? If those are good then focus on the carb. After sitting for 3 years and then running you might have something clogged. You might want to bite the bullet take it to a marine mechanic that will get it running.

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had a techie in today, he said it was not the carb, plus i had the carb apart and all the jets cleaned. the spark plugs are wet after running. it is not the carb, but an ignition problem. the compression as had mentioned before was 100 psi on both cylinders. the spark is most likely breaking down.

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Go to this website. Click on technical Support. Spark problems mean you have


1. a bad stator (sends the trigger to the CDI box)  or


2. a bad CDI box. (develops the pulse for the coil)


3. or a bad coil (develops the high voltage pulse to the spark plug).  The information on this site will tell you exactly how to troubleshoot it.


If you have a coil for each plug, and none of the plugs are firing,then it is not the coil. It must be the CDI box or the trigger coil (stator) under the flywheel.







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