2000 johnson 40hp 2s. Idle out of gear fine but dies in gear 30s later

alexh86

Cadet
Joined
May 24, 2010
Messages
10
This is a bit difficult to describe but I will do my best.
Basic engine info:
The motor starts up and runs as it should and so far I am very happy with the motor. The VRO was removed due to a fuel leak and a reg pump was put in. I can reach full speed and rpm without any issue.

The problem:
The motor will idle out of gear all day long. It sound pretty smooth, and there isn't much change in rpm at all. Once I put the motor into gear, the engine rpms fall slightly as they should, but then the motor begins to run a little more rough, and starts to bog. This continues, and continually gets worse until the motor will eventually die. Currently, in order to get around this, I am having to go back into neutral, where the motor seems to "catch up" and climb back up to a normal, smooth idle- takes about a second. Another way around this is once I think its about to die, I give it more gas and there is a slight hesitation until it can catch up in RPMs -usually only a couple seconds. Anything above a high idle and the motor is fine all day long. I know i could just increase the idle and let it go, but I do not want to beat up the lower unit. I also slow troll and cannot yet do this because of the bogging issue. I have adj. the low speed screw everywhere - nothing reallly helps.

Do you think the carb floats are not set correctly? I have also read it might not be getting a strong enough spark? I have gone over the engine several times and looked for fuel leaks and havenot found any. Seems to me its running too rich at idle, and when I give it more gas it takes awhile to clear itself out. Low speed needles do not really change a lot- started with the base of 2.5 turns out and went all over the place from there.

Any ideas?
Thanks,
Alex.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 2000 johnson 40hp 2s. Idle out of gear fine but dies in gear 30s later

Make sure the low speed needle valves are adjusted properly. If the idle speed is not at the proper RPM it could cause your problem. If the idle speed is correct when you shift do not try and ease it into gear, snap the shifter and put it in gear quickly.
 
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