1992 Evinrude 150hp EXEN will not run correctly

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Aug 4, 2002
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58
Back again.... Back to square one... Took the boat out today and it will not run when I give it any throttle, it idles kinda rough but just bogs down. This is getting very frustrating, as it has to be something simple. It seems like it's not getting enough fuel or it's in limp mode. I have checked the temp with an IR and it reads about 130 on both heads top and bottom. . Since my last post I have replaced the T-stats, put in new T-stat and cylinder O-rings, new starboard temp sensor, rebuilt the carbs, new floats (I did make sure they were adjusted correctly), needle valves, gaskets and new float bowls as the others were warped and I did not feel comfortable sanding them down, new optic sensor, checked the spark all cylinders throw a good spark solid 1/2"+, new plugs and wires gapped 0.30 new fuel/water separator, what have I missed??
 
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saltchuckmatt

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Back again.... Back to square one... Took the boat out today and it will not run when I give it any throttle, it idles kinda rough but just bogs down. This is getting very frustrating, as it has to be something simple. It seems like it's not getting enough fuel or it's in limp mode. I have checked the temp with an IR and it reads about 130 on both heads top and bottom. . Since my last post I have replaced the T-stats, put in new T-stat and cylinder O-rings, new starboard temp sensor, rebuilt the carbs, new floats (I did make sure they were adjusted correctly), needle valves, gaskets and new float bowls as the others were warped and I did not feel comfortable sanding them down, new optic sensor, checked the spark all cylinders throw a good spark solid 1/2"+, new plugs and wires gapped 0.30 new fuel/water separator, what have I missed??
Compression test?

Did you try pumping the primer ball?
 
Joined
Aug 4, 2002
Messages
58
Compression test?

Did you try pumping the primer ball?
compression is now at 100 - 105 . while it was running I was pumping the bulb and there was no change... I've been doing some research on the blocking diode?!? could this perhaps be an issue, something I have not replaced YET...when I bought this boat all the wiring was a mess to say the least... I had to rewire the temp sensors to the alarm and replace the alarm as it was rusted shut. It does sound when I ground out the tan wire but does not chirp when I turn the key on...
 
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Aug 4, 2002
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58
If only rough in gear it may be a problem with the shift interrupter switch.

would that cause the motor to bog down and die when given throttle which is the major problem. When I idle out past the no wake zone and give it some throttle it just runs rough as hell then dies if I don't put it back to idle then I have to really baby it back to the dock
 

dwco5051

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Sep 14, 2008
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The shift interrupter momentarily cuts power to one bank of cylinders as the shifter goes from neutral to forward to ease stress on the clutch dogs. A bad or sticky switch or one with improper adjustments could cause the problem you are having. It has been a while since I sold my boat with a V6 Evinrude and my factory manual was thrown in with the deal so my memory is a little vague on the exact wiring plus mine was a 1990 so there may be a difference. The blocking diode being bad (shorted) would kill both banks. If it failed open it would make no difference. Disconnecting the ground from the switch should cause the problem to go away but do it only as a test as it will cause stress on your lower unit to operate it that way in normal operations. Hopefully someone with more experience with your year and model will chime in and correct me if I am wrong. The older I get the more I have learned not to rely on my memory.
 
Joined
Aug 4, 2002
Messages
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The shift interrupter momentarily cuts power to one bank of cylinders as the shifter goes from neutral to forward to ease stress on the clutch dogs. A bad or sticky switch or one with improper adjustments could cause the problem you are having. It has been a while since I sold my boat with a V6 Evinrude and my factory manual was thrown in with the deal so my memory is a little vague on the exact wiring plus mine was a 1990 so there may be a difference. The blocking diode being bad (shorted) would kill both banks. If it failed open it would make no difference. Disconnecting the ground from the switch should cause the problem to go away but do it only as a test as it will cause stress on your lower unit to operate it that way in normal operations. Hopefully someone with more experience with your year and model will chime in and correct me if I am wrong. The older I get the more I have learned not to rely on my memory.
HMMMmmmmm... I'll have to look at that tomorrow morning. I'll disable the switch and see if that does it. Yes, with age comes memory loss, but for some reason we tend to remember the good times
 

dwco5051

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Sep 14, 2008
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HMMMmmmmm... I'll have to look at that tomorrow morning. I'll disable the switch and see if that does it. Yes, with age comes memory loss, but for some reason we tend to remember the good times
Here is an old thread on that switch. A lot of good info there;

 
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Aug 4, 2002
Messages
58
So, before I take this down to the landing and pay another 20 bux to find out it's still not running is there anything else I can check while I'm there?
 
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racerone

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Dec 28, 2013
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Primer bulbs do not need to be hard when motor has started!----A simple fact mis-understood by many.----But it should go hard after 1 or 2 squeezes when motor is running.
 
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Aug 4, 2002
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Just got back from running the motor. The video "Motor 3" is what happens when I begin give it throttle, it just bogs right down like it's being starved. The other two are at idle at the dock. During this test I had the neutral switch disconnected as well as the two temp sensor switches, this changed absolutely nothing, sure does smoke though... I checked the cylinder temps after it ran for a bout 15 minutes, the port side stayed around 100, the strbd stayed around 115 so temp is not an issue... I hope this helps...
 

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racerone

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Simple test.-----Does spark jump a gap of 7/16" or more on each lead , yes or no.
 

racerone

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Did you remove high speed jets from old bowls and install them in the new bowls ?
 
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