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HELP, 1989 70 hp Fuel Problem??? Thanks!

J

John Haggerty

Contributing Member
Thanks for your time,

I have a 1989 Johnson 70 hp engine. I've never had any real problems with it over the years. Last time I ran it 6 months ago, it ran fine. I almost always disconnect the fuel line when I know it will sit for awhile, as I did last time it ran correctly.

Yesterday, after not being run for 6 months, it started but I couldn't keep it running. The only way I could keep it running was to press the key in and act as a "human fuel pump/injector". I was able to run pressing the key as the rpms would slow down about 20 minutes at 2,000-3,000 rpm. After that nonsense I gave up and went home. I suspect I could get it to fire right up, but would still need to use the key to get fuel to it.

Any ideas as to what is up? I suspect either bad carbs or bad fuel pump. With 20 minutes using the PITA method, wouldn't the carbs kind of clean themselves and allow it to run better (which didn't happen). Any help would be greatly appreciated.

Thanks,
John
 
If it runs better when you push in the key it sorta proves that the fuel pump is providing pressure to the primer valve.-------When you push in the key the primer valve opens and allows the fuel pump to push fuel into the motor.-----The primer itself is not a pump of any kind !------So I would start with inspection and carburetor cleaning and most of the time there is no money involved in that project.
 
So what method should I try first to clean the carbs? Is it just some solvent type injection with carbs still on, or is a removal, cleaning and replacement? I'm currently not at home with access to a good set of tools and a workbench. I'm in a RV park with limited ability to work on the motor.

Thanks for you time,
John
 
Take the float bowl plugs out, pump the primer bulb and make sure fuel comes out of the bowls. The high speed jets are under the plugs. Get a packing wire and run it through the jets and see what happens.
 
The only reliable way to repair carbs is to get the repair kits, a couple cans of carb cleaner, a can of WD40 (to clean plastic parts), remove them, and follow a rebuild procedure. It's not rocket science but with the cost of parts at around 50 bucks it's just not worth half assing it. I recommend getting kits with the floats.

As far as space, once you have the carbs off and the parts cleaned up (which probably needs to be done outside anyway), you can rebuild them inside a shoe box - I've actually used a shoe box a few times for this. Tools needed are very limited - screw drivers, small sockets, the right open end wrench, needle-nose pliers.

Don't even bother spraying crap into the carbs - it's not a car, not that it works that way with a car, but isn't even worth the trouble with an outboard.

Jon
 
Thanks for the help. Bought 3 carb kits with floats. Removed, cleaned carbs with carb cleaner and replaced. Fired right up and idled right away.

One issue. Upon replacing I broke a plastic fuel line tee. What a PITA to find.

After seeing how simple it was, probably could have gotten by without the kits and only cleaner.

Thanks for all the help.
 
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