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Johnson 25 Idle Adjustment Help

J

Jcqsrbrts

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I’ve got a new to me 92 Johnson 2cyl 2 stroke (J25TEEND). The previous owner has the kill switch disconnected and uses the tiller handle to kill the motor. At about 1/4-1/2 twist of the tiller is when it seems to idle and if you go below it will stall. Does anyone know what adjustments I can make to have it so where no throttle is idle? Thanks!
 
racerone said:
Is the motor in good condition to idle properly, yes , no or not sure ?-----What trouble shooting have you done ?
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Motor runs great and idles perfectly at 1/4 throttle. this really isn’t an issue. My first thought was adjust the carb idle screw but I’m thinking it has more to do with the cable adjustment. The only reason I’m trying to mess with it is because the wife struggles with killing the motor when she drives and wanted to make it so where it idles when the tiller is 0 throttle. I assumed that’s how tiller handles normally operate but if having the tiller at no throttle is normal for the motor to die then that’s fine.
 
Jcqsrbrts said:
Motor runs great and idles perfectly at 1/4 throttle. this really isn’t an issue. My first thought was adjust the carb idle screw but I’m thinking it has more to do with the cable adjustment. The only reason I’m trying to mess with it is because the wife struggles with killing the motor when she drives and wanted to make it so where it idles when the tiller is 0 throttle. I assumed that’s how tiller handles normally operate but if having the tiller at no throttle is normal for the motor to die then that’s fine.
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Hey did you ever figure this out? Same problem on my 1992 25hp evinrude, cleaned carb and reset idle adj screw, didnt matter….
 
Jstay0 said:
Hey did you ever figure this out? Same problem on my 1992 25hp evinrude, cleaned carb and reset idle adj screw, didnt matter….
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When you cleaned the carb, did you remove all the welch plugs, clean every passage, then reassemble? If not, you could have still have some crud lodged in a fuel circuit. Also, make sure you have good compression on both cylinders and your fuel pump is in good shape.
 
kevinj said:
When you cleaned the carb, did you remove all the welch plugs, clean every passage, then reassemble? If not, you could have still have some crud lodged in a fuel circuit. Also, make sure you have good compression on both cylinders and your fuel pump is in good shape.
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Yeah, i cleaned it once without removing the welch plugs. Took it off cleaned it again, took out all welch plugs. Used a thin guitar string, even went through the tiny holes in the middle of the throttle body just un the butterfly which i read is linked to the low idle jets. Also, sunk the carb for 15 min in that berrymans chem dip. Also, took off the fuel pump, everything looked new. Diaphragm was not worn or dry rotted. No leaks ect. I can keep it running on lower throttle only by tightening the end of the tiller handle. When i tighten the handle, it essentially is just increasing the roller on the cam thus increasing throttle position and locking it in place….
 
Jstay0 said:
Yeah, i cleaned it once without removing the welch plugs. Took it off cleaned it again, took out all welch plugs. Used a thin guitar string, even went through the tiny holes in the middle of the throttle body just un the butterfly which i read is linked to the low idle jets. Also, sunk the carb for 15 min in that berrymans chem dip. Also, took off the fuel pump, everything looked new. Diaphragm was not worn or dry rotted. No leaks ect. I can keep it running on lower throttle only by tightening the end of the tiller handle. When i tighten the handle, it essentially is just increasing the roller on the cam thus increasing throttle position and locking it in place….
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Jstay------What trouble shooting has been done.----Post the actual compression test values.----And was this poor idle a sudden development ??----How long have you owned this motor?
 
I bought this motor new to me, just last week. 1992 Evinrude 25hp. Original owners manual. Original evinrude engine cover.paint looks completely new. Original owner past away had original receipt, the guy got cancer unfortunately and only was able to use it a year or so when he bought. Son was selling it under the family trust. Only used on a 14’ alum. StarCraft boat. Compression numbers cold, on my new amazon branded compression tester showing 118/119 top/bottom. I know its not a snap on compression tester. Its all i got. New spark plugs installed. Spark light tester showing light on both plugs. Changed lower unit oil. Just put in new water impeller assembly last night. Surprisingly, impeller was not too bad looking. Original paint on the screws of lower unit. Its mint. Family said it had about 10 hrs on it.
 
only odd thing i noticed on the fuel pump was a small tear in the orange gasket inside fuel pump, would this cause a low idle issue? See picture below along with lowest throttle position on cam roller…
 

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