69 9.5 Evinrude spuddering/coughing

doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
Hey y'all I'm trying to figure out why my 9.5 won't run right or idle properly, I've replaced the entire ignition system new wires, plugs coils condensers, carburetor cleaned and rebuilt and it just won't idle properly it coughs or sneezes really bad no matter what I do to the slow speed adjustment needle, fuel pump appears to be working properly primer bulb nice and hard while running, I'm stumped at this point tried everything that I can think of
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,502
Does throttle plate go closed at idle ?----Does throttle plate open at the correct time ?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,502
There is a mark on the cam.----That is the point where throttle plate opens.----At idle there usually is a gap between follower and cam.-----If throttle plate is open it will not idle properly.
 

McGR

Senior Chief Petty Officer
Joined
Jun 19, 2004
Messages
664
Does it do this with the cowl removed? Exhaust leaks are known issue with the 9.5.
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,687
see adjustment

how did you clean the car totally or partially ..?? is the float adjusted ok

did you inspect and clean out the HS jet behind the bolt at the bottom
did yoy total clean the low speed circuit by removoving the plugs on top....see leroys on MQ's
these 9.5 must be 100 % clean .

did you adjust timing ?
 

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doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
Totally took carb apart, Welch plugs included,high speed jet out and cleaned,float is level is parallel to the carb body,only thing I haven't done so far is adjust the timing gonna try that today
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,687
the side knob controlling the low speed limit may be to low .... turn it and see the throttle handle rotate to a speedier position towards SHIFT


btw was this engine running so bad ?? to have you change plug wires etc.... was this a sudden issue or are you reviving an oldy ?

did you test compression ...65-70 should do ... mine isn't much higher and runs perfectly all day long idling
 

doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
Ok I'll look into that,put a new head gasket on it,was running way to warm, tried the thermostat and that didn't work, running hot is now resolved.it ran decent when I first got it,but decided to rebuild the magneto,could,points, condensers wires ,plugs
 

doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
I've done all of the above mentioned things,it's made no difference, I've got good spark on both cylinders,fuel pump appears to be working properly,it'll run with choke on but when the choke goes to the off position it spudders then finally dies,the low speed adjustment seems to have no impact on it in any position
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,811
I've done all of the above mentioned things,it's made no difference, I've got good spark on both cylinders,fuel pump appears to be working properly,it'll run with choke on but when the choke goes to the off position it spudders then finally dies,the low speed adjustment seems to have no impact on it in any position
Did you try pumping the primer ball when it starts to die?
 

doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
I've cleaned it out two or three times,just to be certain,far as I know it's the original low speed needle,it looks decent but not sure if that makes any difference,just because it looks good?
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
38,502
Maybe the tip of the low speed needle is broken off.-----This motor should be an easy fix.----But I can't get my hands on it.----Post a picture of the needle.
 

doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
Here's the needle
 

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doors67us

Petty Officer 2nd Class
Joined
Aug 2, 2021
Messages
152
Maybe the tip of the low speed needle is broken off.-----This motor should be an easy fix.----But I can't get my hands on it.----Post a picture of the needle.
Yes I agree with you,this one has given me more problems than any other one I've ever messed with,plus things aren't easy to get to compared to most
 

racerone

Supreme Mariner
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Dec 28, 2013
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Needle looks OK.----But I believe there is an issue with the carburetor.-----
 

doors67us

Petty Officer 2nd Class
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Aug 2, 2021
Messages
152
Ok ,but what could the carb issue be, perhaps the low speed chamber is corrupt? What do you suggest find a new /used carburetor? This issue has been driving me nuts!!
 
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