Thread: 25 hp yamaha 4 stroke 2002 hard to start when cold

I know on my 2-stroke, when it hasn't been ran in a while, I take the motor hood off and flip the little red switch to "closed" that acts as a heavy choke. Once it kicks over I flip it back to "normal" and put the hood back on and proceed as normal. I don't know if 4-strokes have this or not. Should be a sticker on the engine telling you about it, looks similar to this:

Originally Posted by artcarney_agr

I know on my 2-stroke, when it hasn't been ran in a while, I take the motor hood off and flip the little red switch to "closed" that acts as a heavy choke. Once it kicks over I flip it back to "normal" and put the hood back on and proceed as normal. I don't know if 4-strokes have this or not. Should be a sticker on the engine telling you about it, looks similar to this:

Closed position turns off the added fuel enrichment. On position is a manual over ride for extra fuel. The auto position should be all you need. If you are having issues that requires any change from auto to assist in starting, you have a problem in the enrichment system.

Originally Posted by ichabod

starts fine rest of the day . have to push throttle wide open a few times and then start. may have to do that 2 or 3 times to get it to stay running. is this normal for a 4 stroke yamaha?

There's an auto enrichment system on the carb that is giving you problems. Unlike the other motor mentioned above, you do not have a manual over ride option. The fuel circuits in your carb are very small and easily obstructed. It sounds like you are managing to start the engine with added fuel from the accelerator pump. My best guess from your description is that the circuit that supplies fuel to the enrichener is blocked or restricted.

Originally Posted by sliderman

Closed position turns off the added fuel enrichment. On position is a manual over ride for extra fuel. The auto position should be all you need. If you are having issues that requires any change from auto to assist in starting, you have a problem in the enrichment system.

Just so we're clear....

On mine, a 2-stroke, 3 positions on mine..."Normal" "Open" and "Close"

When mine hasn't been ran in a while, I flip it to "Close" and then it fires right up, then I flip it back to "Normal" and never have to touch it again until the boat has sat unused for 2 weeks or more. Been doing this for almost 10 years.

Are you saying that the original poster, ichabod, does not have this setup because his is a 4-stroke and it's all electronic with no levers to manually flip? That his system is possibly experiencing failure in the electronics that operate it?