Johnson 9.9 Question

[Coadster68]

Hello all,

First off let me say what a wonderful forum. I have a few questions about my 9.9 Johnson. My grandfather passed away a few years ago, and he left me his boat and motor. I am led to believe that the motor is from 76, I checked on the trailer and it says 76, so im assuming he bought the boat/trailer at the same time he bought the motor. Anyway, I put a bunch of money into last year ('round 600) Replacing this and that, doing it by manual and knowledge (Im only 15 ). I put a new top end in and stuff. anyway, The motor ran GREAT last year, always started second pull when cold. But, as I was pulling it out of my garage, I noticed the Dial on the front beside the choke had been tampered with, it was set to full. (Probably my 6 yr old brother). I think its the air/fuel mixture dial. SO what im asking, how do i tell if its set properly? I'll be going up north tomorrow morning so I just want to get some advice on how to set it.

Thanks everyone.

 

[Xcusme]

Re: Johnson 9.9 Question

Welcome to iboats!



(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle valve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

 

[Coadster68]

Re: Johnson 9.9 Question

Thanks, I understand how to set the HS/LS, but could you tell me exactly what the dial is on the front beside the choke?

 

[CatTwentyTwo]

Re: Johnson 9.9 Question

On my 84 9.9 that knob is labeled Slow Speed Adjustment with Lean and Rich markings. I would set the pointer at 6:00 and then adjust it as Xcuseme described when you get on the water. My motor idles better if I turn the knob about 1/8 turn toward lean when I get on a lake above 5000 ft. in the Sierra's.