Carb question-89 Johnson 60HP

[DumbBass]

I just rebuilt my carbs,thanks to all of the great information available on this site. I used the factory rebuild kits, followed the factory service manual and everything worked fine. I have a question concerning the idle mixture adjustment. The service manual indicates the adjustment should be 2 1/2 turns out from all the way in. Before rebuild, the top carb was set very close to this, but the middle carb was only 1 turn out; the bottom carb was 1 1/4 turn out. I adjusted mixture the same as before rebuild. These adjustments would seem to create a "lean" condition but the motor runs as if it is "rich" at idle; occasionally rough, not a hiccup or backfire indicating lean condition. I plan to run boat in the water tomorrow and adjust idle mixture per manual. Any feedback/recommendations on this situation would be appreciated.

 

[JB]

Re: Carb question-89 Johnson 60HP

Howdy, DB.<br /><br />You have a good plan.<br /><br />Idle should never be adjusted without the engine in the water. You need that backpressure to get it right.<br /><br />Good luck.

 

[Yepblaze]

Re: Carb question-89 Johnson 60HP

Not absolutely sure about your particular units but some carbs use an idle air bleed screw which in turn acts in a reverse (in rich/ out lean) way.

 

[DumbBass]

Re: Carb question-89 Johnson 60HP

Thanks for the replys. Yepblaze, manual indicates clockwise(in) to make leaner.

 

[DumbBass]

Re: Carb question-89 Johnson 60HP

I took the boat out yesterday and idle still seems a little rough, wants to stall at idle of 800RPM when in gear. As stated above, middle and bottom carb idle mixtures are set at 1 turn out and 1 1/4 turn out which seems lean according to manual. Adjusting richer resulted in rougher idle. Any ideas as to why these two carbs would be adjusted so different from the manual recommendation of 2-21/2 turns. Is it possible choke solenoid is leaking additional fuel into carbs? I noticed choke solenoid has two feeds, one to the bottom 2 carbs and one to the top carb.<br />Motor does seem smoother at all other throttle setting after carb rebuild.

 

[OBJ]

Re: Carb question-89 Johnson 60HP

Hey Bass. (Notice I left the "Dumb" part off)<br />The starting point the service manual suggests is just a starting point. This gets you going and the final adjustments are made from here. During the rebuild, did ya notice how the reeds looked? Were they flat against the cages? A good way to check the primer solenoid when the engine is running is to pinch of the supply hose from the fuel pump. If the idle improves, then the solenoid is passing gas (Not that way!) when it shoudn't. This will give you a poor idle and making carb adjustments is really tough to imposible. Keep us posted and good luck.