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Slow Speed Carb Adjustment 90hp Johnson

M

magnet

New member
The factory service manual discusses exhaust back pressure and the need to make this adjustment in the water with neutral trim and in forward gear. I've had many outboards in my time and was always able to make this adjustment "in the yard." How necessary are the above-mentioned requirements?
Thanks,
Magnet
 
It is allways best to adjust the idle air and idle speed in a barrel or on the water with the engine in forward gear. On the muffs you can get it running good but with the added backpressure and load on the prop you will be running too lean. Allways adjust the fuel mix a little rich especially if you do alot of slow speed operation. It helps with cold starts and will give you a better hole shot as well plus it protects the motor.
 
With experience you can get it "close", but to get it right you need to have it in the water as the book says. Especially the idle speed (RPM).
 
This model has a "bungee cord" means of securing the air silencer to the motor. The lower bungee on the port side (highlighted in red) is extremely difficult to access. Is there a special tool required just to remove/install the silencer?
LowerBungee.jpg
 
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