1975 Johnson 25hp dies at idle

agib08

Cadet
Joined
Jun 13, 2010
Messages
21
My 1975 Johnson 25RL75B dies anytime I throttle it down to low throttle to shift. I'm thinking my links and everything may not be set right. Any suggestions on what to check? Anyone have a manual or can tell me how to adjust all the links and whatnot? I really don't like shifting it without going to low throttle. I have adjusted the low speed to the best of my knowledge on how to do that. Sorry if this is confusing. I'm typing while watching football.
 

hardwater fisherman

Lieutenant Commander
Joined
Mar 19, 2010
Messages
1,725
Follow the tiller handle to the back. And on the back side of the gear , there is a idle stop screw.If original it will be a white long plastic screw with a spring. Often they are broken or missing. If you have to you can find a bolt or screw to take its place. This will prevent the idle from dropping too low and also you can use it while trolling or moving slow without twisting the throttle.
 
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agib08

Cadet
Joined
Jun 13, 2010
Messages
21
Mine has the white one. The issue I'm running into is when I turn the throttle down to where it says shift, slow, stop it dies. I can't even get it to the shift part without it dying. Should I disregard the labels on the throttle?
 

ondarvr

Supreme Mariner
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Apr 6, 2005
Messages
11,527
And the markings mean nothing after all these years, they rarely line up correctly.
 

agib08

Cadet
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Jun 13, 2010
Messages
21
The motor does run at about quarter throttle and up and moves my boat along at full throttle with 2 people in it if that helps.
 

ondarvr

Supreme Mariner
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Apr 6, 2005
Messages
11,527
As mentioned, check compression, then clean the carb.
 

lindy46

Captain
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Nov 27, 2008
Messages
3,886
As mentioned, check compression, then clean the carb.

And make sure to clean the idle circuit under the plug on top of the carb. Make sure the tip of the needle is good and the orifice (seen from inside the idle circuit) isn't cracked or chipped.
 

agib08

Cadet
Joined
Jun 13, 2010
Messages
21
I cleaned it all and followed all the tips and it seems to be running good now. Thank you all!
 
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