gas leaking from prop

[cbsykes]

I recently noticed on my 2004 25hp Yamy outboard that gas was leaking from my prop and also from underneath the housing coming down the shaft. Does anyone know what might be causing this? I ran the engine about a week ago with no problems at all. Walked out to the boat today and noticed all the gas leaking. What gives?? Any thoughts are appreciated.

 

[rodbolt]

Re: gas leaking from prop

could be a carb needle, could be a bad fuel pump diaphram. something is dumping fuel into the crankcase area and its running out the exhaust.

 

[cbsykes]

Re: gas leaking from prop

Thanks for the quick reply! Also, I cannot pull the start rope but about halfway and as soon as I do...gas leaks out of the prop. Would this indicate anything? Just weird how this happened when the engine was just sitting in the garage.

 

[drewmitch44]

Re: gas leaking from prop

If you are using those portable plastic gas tanks sometimes ive noticed that when the sun beats on it, it builds up a lot of pressure. It could be causing the fuel to force its way out the carb somewhere or where there is a little leak in the fuel system somewhere. When those tanks have the sun beating on them it puts a lot of pressure on the fuel system because of the built up pressure in the tank.

 

[cbsykes]

Re: gas leaking from prop

Well, now that you mentioned it...my boat did sit out in the sun for a few days after I used with the vent screw on the portable tank tightened. So, if in fact, this caused the fuel to leak all over the place...could this have damaged anything in the process? How can I be sure this is the culprit? Maybe I should take it in to get it checked out just to be sure. Or do you think everything should be ok? Thanks for your help.

 

[drewmitch44]

Re: gas leaking from prop

its hard to tell. The only reason i said that is cause a tech told me one time that, that was the reason that i was replacing fuel pump gaskets so oftenly. It was cause the pressure that builds up in the tank. Im not saying that, that is your problem. Just possible. What it did on my evinrude was cause the gasket to push out of the housing on the fuel pump and then dry and crack. I dont know if that is your problem but i unplug the fuel line since then when i use those plastic tanks.

 

[BruceAML]

Re: gas leaking from prop

Do you have a genuine Yamaha fuel line assembly? If not I would suggest that you get one as they are of a much higher quality and have better check valves. What brand of gas tank are you using?