1996 Johnson 25HP wouldn't idle properly

This is a two-cycle engine, when I try idle the motor to troll, it stalls out frequently. Also if motor has been at idle speed for a period of time, when I try to accelerate the engine, it sounds like it is running on one cylinder (low power). After a brief moment, it seems to clear our and begins to accelerate. Is this a problem with the carb or electrical?

When was the last time you cleaned the carbs and try to do a spark test it should be a bright blue/white spark it sounds like a carb issue

Thank you for the response. I just had the boat & motor in to the marine shop, they said the carb looked good. They had replaced the shift and throttle cables on the control, the idle speed was high so I tweeked the adjustment screw on the carb. It slowed the idle, but it seems to be running rich (however the plugs looked good). Should the idle speed by adjusted through the cables or the carb?

Adjust with the cables !

racerone said:

Adjust with the cables !

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racerone - thank you for your response, I also spoke to the tech at the Marine shop, he said if the linkage is set to idle stop under the fly wheel, the linkage is proper. There is also some minor adjustment that can be made in the linkage at the carb. The needle screw on the carb is the idle mixture screw (this is the one I adjusted) I submerged motor in a barrel of water, ran the engine and adjusted the mixture needle, runs much better. I also did minor adjustment to the linkage on the carb. Tech also said if this doesn't get your idle speed down to the desired level, the timing will need to be checked and possibly adjusted

Timing on modern outboards rarely needs adjustment.-It is set at the factory !

I have somewhat the same issue, removed the carb and found the rubber hose from the side of the cylinder block running up near the bottom of the carb was not attached to the motor anywhere ? any suggestions? there is a nipple on the intake manifold but it is much larger dia. than the hose.

I have somewhat the same issue, removed the carb and found the rubber hose from the side of the cylinder block running up near the bottom of the carb was not attached to the motor anywhere ? any suggestions? there is a nipple on the intake manifold but it is much larger dia. than the hose. mine is a 1974

That was a special " moulded " hose with 2 different size ends.