I have recently acquired a 1994 Sylvan Classic 14ft fishing boat with a 1994 Yamaha 25hp outboard motor(model C25ERLS). The motor had a new fuel pump and carb rebuild kit put on it when I purchased it. The motor runs great but not for very long after it's initial start. It won't run higher than idle without losing prime. I have replaced the gas tank and primer bulb and I have not found any leaks in the fuel line as it is fairly new. Could it be filter, plug or some other part I am over looking?
rule of thumb is. remove the float bowl and turn the carb over(so its upside down). the bottom of the float should sit parallel with the float bowl mounting surface.
If you are referring to the fuel filter, Yes, the filter is brand new as is the fuel pump and fuel lines. I changed those all myself after buying it hoping that was the problem. Those things have made it run a LOT better. I can now run it at about 3/4 throttle instead of 1/4 when I first bought it. The only thing I haven't taken off is the carb. Should I order a rebuild kit and go that route right off the bat? I don't really have the extra $$, so if I can clean it up that's my hope.Thanks guys.
I had a problem with sputtering and rough running and I just cleaned the fuel filter replaced the fuel pump and cleaned the deposits from the carbs.I also blew out the jets voila a new motor. Maybe you have something in the jets. Sorry I can't help more.
Sylvan, before you tear down the carb or carbs, try this.I think you may have a stuck float. Could be 1 or all of them. If you have only 1 carb this will be so much easier. Have you noticed gas pouring out the top of the carb? If so your float is stuck. If your dont see this I don't think the float is your problem. You can check this by removing the hood and pumping your bulb looking for any gas pouring out the carb(s). Point the bulb arrow to the sky when doing this. If your bulb tightens you DO NOT have a issue with your hoses from the tank to the float.If it DOES NOT tighten do this.On the bowl of the carb you will see a drain screw. Best to use a socket to remove it. Get a slim piece of strong wire and bend it into a long hook. Snake the wire into the drain hole in the direction towards the plugs, now twist the hook up and see if you can move or free the float. Now go back and retest the hoses and float.If that dont work....pull the carb.Its not real hard. Just a PIA.