Idle Adjustment...HELP !!

16Pilot

Petty Officer 1st Class
Joined
Mar 18, 2004
Messages
205
ok guys this is what my problem is! I have a 1970 9.5 Johnson that has two idle adjustments, one on the side for high speed that adjust the linkage and one for slow speed. They are completely screwed up because when I am at full throttle it only goes half speed and catches up once in a while when I play with the adjustment. Where is the best place to set the two from the start ?<br /> Thank You
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: Idle Adjustment...HELP !!

Do you mean the screw that locks the syncronization between the spark advance (armature plate under the flywheel turning) and the throttle butterfly opening?<br />If so, you loosen that screw and adjust the throttle lever so that when the throttle butterfly *just* begins to move, the lever is centered on the mark on the cam.
 

16Pilot

Petty Officer 1st Class
Joined
Mar 18, 2004
Messages
205
Re: Idle Adjustment...HELP !!

no it is the exterior adjustment knobs, one say's rich or lean and the says high speed, that actually controls the assembly inside to the throttle linkage when I turn it
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Idle Adjustment...HELP !!

16pilot.....I think your referring to the throttle control on the tiller handle that controls the throttle plate?<br /><br />Lightly seat the low speed needle (the knob marked lean/rich) and back out a turn and a half. Warm the engine up. This proceedure is best done with the motor on the boat and in the water. Run the engine at full throttle to warm it up and clear it out. Back the throttle down to slow. Turn the slow speed needle in 1/8 turn and give the engine time to respond. You will get to a point where the engine will start to idle rough. Back the needle out 1/4 turn. This should be all you need to do if the carb is clean and ignition is work as advertised.<br /><br />I hope this is what you were looking for....thanks.
 

16Pilot

Petty Officer 1st Class
Joined
Mar 18, 2004
Messages
205
Re: Idle Adjustment...HELP !!

thanks OBJ I will try that today and let you know how it goes, as long as it stops raining
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Idle Adjustment...HELP !!

If I have this strait, The knob on the side of the engine is the idle stop screw. You adjust this to control engine speed at idle to prevent stalling. The knob on the front is the idle mixture screw to the carb. There is no high spped adjustment, it uses a fixed jet.
 

Xcusme

Commander
Joined
Apr 21, 2003
Messages
2,888
Re: Idle Adjustment...HELP !!

Yup, that's it...<br />You may have to pull the idle mixture knob out (the one on the front of the motor)to clear the stop so you can screw in the needle valve as OBJ mentioned, until it lightly seats.
 

Bass Runner

Senior Chief Petty Officer
Joined
Apr 2, 2004
Messages
746
Re: Idle Adjustment...HELP !!

a good setting is one turn out for the high speed and 1 1/2 turn for the idle, start the motor and let it warm up then play with the idle adjustment untill the motor idles the best, then take it out and run wide open and play with the high speed jet till you get the best top speed then back it out just a little you don't want it to lean. Hope this helps
 

Xcusme

Commander
Joined
Apr 21, 2003
Messages
2,888
Re: Idle Adjustment...HELP !!

Bass Runner,<br />That's good advise for those folks that have motors with 2 carb mixture screws, but this motor has a fixed high speed jet-no adjustment, except for having a clean carb.
 
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