1996 115 Johnson Ocean Runner V4 Will Not Idle J115SLEDR

sguidry

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Oct 31, 2022
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*Compression 121-131 all cylinders
*Has spark from all plugs (7/16" jump)
*fuel is getting into motor (visually seen fuel coming from the carb jets into the motor)
*Fuel being held via external tank ( because the boat tank is in the process of being cleaned)
*NON-VRO FUEL PUMP, (it has a small low volume electric fuel pump)
*Miss fire, Backfire
So start out I received this boat as a gift to repair. The previous owner stated that all it needed was the carbs rebuilt. I ordered a kit online cleaned the carbs, all the ports with compressed air, rebuilt the carbs. Installed them and it fired right up and then died. Well I put the motor in a test tank (trash can) to run it again so I would not burn it up. I went to start it again it would not idle, however if I started it up and then put it into gear it will run. So I decided to take it out to test it on the water. Same issue would not idle, but will run WOT. Well I took it out about three more times to see if anything changed after messing with fuel lines and the carbs again, and this last time it was running like usual (still not idling) I was on my way in and then the motor revved up really high ( sounded like it was about to explode) and took off, then it slowed down again, it revved up again and took off again, (it did this three times before dying completely). Turns out the electric fuel pump came unhooked (or so I thought this was the problem) I hooked the pump back up on the water. It would not fire up unless I pressed the electric choke in. Well to get back to the boat ramp I had to continuously push in the electric choke about every two seconds to keep the engine running. ( even in gear) Not mentioned beforehand, to keep it idling while it was not in gear I had to press in the electric choke . This time I had to press it in while the motor was in gear to keep it going. I got a service manual and it turns out I had the floats set incorrectly. So i set them according to the repair manuals specifications ( 11/16"- 1-1/8") , I thought this was maybe the idling problem. Well I'm still having the same issue the boat will not idle, and it is accompanied by a miss, and backfire. I have looked at the timing and it seems to be correct. I am by no means a mechanic by trade, but I can change parts out. I see there is an idle adjustment screw on each carb but I have no clue which way to turn it? Does anyone have any suggestions to what could be the issue?
 

racerone

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Dec 28, 2013
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37,830
When you push in the key the electric primer VALVE opens.-----This puts fuel directly into the engine.----This fuel bypasses the float bowls and metering circuits.-----This suggests to me that you need to revisit carburetor work and adjustment.
 

Faztbullet

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Mar 2, 2008
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15,905
Need to pump a mechanical pump back on it as electric may not supply enough fuel to keep carbs filled.
 

sguidry

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Oct 31, 2022
Messages
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Need to pump a mechanical pump back on it as electric may not supply enough fuel to keep carbs filled.
The guy I got it from said it’s been on there about two years and it would run fine so I may end up going back to the mechanical pump.
 

sguidry

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Oct 31, 2022
Messages
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When you push in the key the electric primer VALVE opens.-----This puts fuel directly into the engine.----This fuel bypasses the float bowls and metering circuits.-----This suggests to me that you need to revisit carburetor work and adjustment.
How would you adjust the carburetor on this particular model? I see a screw on the throttle body, but the only thing I could possibly adjust in the carbs is the float and I set those by the book. Also I noticed today that my electric choke was leaking, when you press the key choke in it squirts fuel out the electric choke could that cause this non idle issue as well?
 

racerone

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Dec 28, 2013
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Get the repair kit for that electric primer valve.----Easy to install .-----Test run.-----The red lever is in the run and not in the manual operation position ?
 

sguidry

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Oct 31, 2022
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Get the repair kit for that electric primer valve.----Easy to install .-----Test run.-----The red lever is in the run and not in the manual operation position ?
I'm about to order that as we speak. I'm at the point where I'm just fixing things and putting it back to how its supposed to be at this point. I've had the carbs off at least 5 times in the past two weeks working on them.
 

sguidry

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Oct 31, 2022
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I'm about to order that as we speak. I'm at the point where I'm just fixing things and putting it back to how its supposed to be at this point. I've had the carbs off at least 5 times in the past two weeks working on them.
Yes racerone it is in the run position.
 

racerone

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Dec 28, 2013
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Carburetors off 5 times ???-----Some say that ---" most carburetor issues turn out to be something else"-----I recall 2 old guys coming into the Johnson dealer 50 years ago.---Said they could not get the carburetor on a 7.5 HP Evinrude adjusted.------A teenage mechanic ( me ) threw it in the test tank and quickly found a blown head gasket to be the issue.----Just saying.
 

sguidry

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Oct 31, 2022
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Carburetors off 5 times ???-----Some say that ---" most carburetor issues turn out to be something else"-----I recall 2 old guys coming into the Johnson dealer 50 years ago.---Said they could not get the carburetor on a 7.5 HP Evinrude adjusted.------A teenage mechanic ( me ) threw it in the test tank and quickly found a blown head gasket to be the issue.----Just saying.
Oof đŸ˜… I surely hope not but I can defiantly rule that out or in if you told me how to.
 

sguidry

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Oct 31, 2022
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I have ran it after that, it still does the same thing like it’s starving for fuel. I have to keep pressing the electric choke to keep the motor running.
I will check compression again and report back my numbers
 

saltchuckmatt

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Jul 19, 2019
Messages
2,647
I have ran it after that, it still does the same thing like it’s starving for fuel. I have to keep pressing the electric choke to keep the motor running.
Running a 2 stroke motor to lean is not good, that's why I suggested to run another compression test. Hopefully your engine is still ok....
 

Faztbullet

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Mar 2, 2008
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15,905
Make sure you did not put the plastic washer under inlet needle when carbs where serviced
 
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