Idle issue with Johnson 90

Idles fine with the muffs on, but in the water, it won’t stay idle. Anyone know how to adjust the idle on 2000 Johnson 90? I can’t find the screw.

You may have more than an idle problem when you put motor under pressure. Might wanna see about getting the carbs cleaned.

Double D.

quote:
Originally posted by TravelinJack55

Idles fine with the muffs on, but in the water, it won’t stay idle. Anyone know how to adjust the idle on 2000 Johnson 90? I can’t find the screw.


I had an 03 same issue. Cleaned carburetors like three times and kept having same problem. Fuel lines were breaking down from the inside and throwing rubber/trash into carbs. In the end I changed all fuel lines inside the motor and fuel line to the tank. Installed fuel/water separator and never had another issue.

Make sure you invest in good quality fuel lines from a marine store. They are lined with special liner that’s resistant to breaking down.

“Endeavor to Persevere.
Give,Give… Never Take.”
EC

quote:
Originally posted by TravelinJack55

Idles fine with the muffs on, but in the water, it won’t stay idle. Anyone know how to adjust the idle on 2000 Johnson 90? I can’t find the screw.


I had an 03 same issue. Cleaned carburetors like three times and kept having same problem. Fuel lines were breaking down from the inside and throwing rubber/trash into carbs. In the I changed all fuel lines inside the motor and fuel line to the tank. Installed fuel/water separator and never had another issue.

Make sure you invest in good quality fuel lines from a marine store. They are lined with special liner that’s resistant to breaking down.

“Endeavor to Persevere.
Give,Give… Never Take.”
EC

do you have a 60 degree motor or a 90 degree motor
in that era they made 2 different 90 2 strokes
the easy way to tell…
do you have 4 small carbs, 2 on each front side of the motor with the fuel and oil pump between the carbs, or do you have 2 big carbs front center and the fuel pump on th eside

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IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING

4 small carbs.

quote:
Originally posted by chris V

do you have a 60 degree motor or a 90 degree motor
in that era they made 2 different 90 2 strokes
the easy way to tell…
do you have 4 small carbs, 2 on each front side of the motor with the fuel and oil pump between the carbs, or do you have 2 big carbs front center and the fuel pump on th eside

www.teamcharlestonmarine.com
www.bombislandboats.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING


you have 60 degree motor, commonly called an “eagle” motor
there isnt an easy “turn 1 screw and adjust the idle” fix
thats why you are not finding the screw.
that is one of the harder motors to get right, so you may want to try and find some youtube videos

www.teamcharlestonmarine.com
www.bombislandboats.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING

adjust needle valve on each carb while in gear in the water is the best answer I’ve come up with.

but then you have to synchronize them as a unit, but its VERY rare that the problem is an “out of adjustment issue”
its almost always something else causing the problem, like debris of bad parts

www.teamcharlestonmarine.com
www.bombislandboats.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING

Just opened my SELOC repair manual… First page says “go buy a Mercury!”

Just opened my SELOC repair manual… First page says “go buy a Mercury!”