# 15 hp Mercury



## shore warrior (Apr 5, 2015)

1999 with hardly any time on it. Cuts out at full throttle? It comes back on if I pull the choke out. Runs great at low rpm. Came with my boat last year. First time we went out it wouldn't start. Took it to Dutch harbor in Berlin. They looked at it and took the gas filter off. Gas was black and had a bad smell. So it was probably a few years old. Flushed that out and emptied the tank. Put fresh fuel in and she started up and ran good. Now when ever I run wide open it starts to die until I pull the choke/primer. Then it runs great. But after we stop to drift it won't start for at least 20 minutes?? Any help is appreciated


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## FISNFOOL (May 12, 2009)

shore warrior said:


> 1999 with hardly any time on it. Cuts out at full throttle? It comes back on if I pull the choke out. Runs great at low rpm. Came with my boat last year. First time we went out it wouldn't start. Took it to Dutch harbor in Berlin. They looked at it and took the gas filter off. Gas was black and had a bad smell. So it was probably a few years old. Flushed that out and emptied the tank. Put fresh fuel in and she started up and ran good. Now when ever I run wide open it starts to die until I pull the choke/primer. Then it runs great. But after we stop to drift it won't start for at least 20 minutes?? Any help is appreciated


Check the O rings on the fuel line connectors. If cracked, you are sucking air at higher rpm. Pulling the choke is giving more fuel. 

I had this happen one year while out camping. Solved it using several layers of electrical tape on the fitting until I could get O rings. Made a pad of take, put a hole in it with a knife, and slipped it onto the fuel nipple so I had to force the connector on. Other issue could be diaphragm in the fuel pump.


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## FISNFOOL (May 12, 2009)

FISNFOOL said:


> Check the O rings on the fuel line connectors. If cracked, you are sucking air at higher rpm. Pulling the choke is giving more fuel.
> 
> I had this happen one year while out camping. Solved it using several layers of electrical tape on the fitting until I could get O rings. Made a pad of take, put a hole in it with a knife, and slipped it onto the fuel nipple so I had to force the connector on. Other issue could be diaphragm in the fuel pump.


Spelling error. That was a pad of electrical tape.


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## FISNFOOL (May 12, 2009)

FISNFOOL said:


> Spelling error. That was a pad of electrical tape.


Make sure your fuel line, including on the motor are ethonal compliant. The black rubber old ones are not. Grey usually is.


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## shore warrior (Apr 5, 2015)

FISNFOOL said:


> Make sure your fuel line, including on the motor are ethonal compliant. The black rubber old ones are not. Grey usually is.


Thanks for all the info fisnfool, going to check all of that out today. Pretty sure my fuel line is black.


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## sherman51 (Apr 12, 2011)

sounds like your high speed jets are partly stopped up in the carb. my brother bought a 65 hp evinrude motor many yrs ago. it ran good at idle. we took it to dale hollow and jumped in the boat and took off. when he hit the throttle it would die. we tried putting gas in the carb at the same time he hit the throttle and it ran good. I tore the carb down at the dock and the high speed jets was completely clogged up. I took a piece of wire and cleaned the jets. then went back out and it run like a scalded dog.

my lawn mower was doing the same thing your motor is doing. at full throttle it ran real rough. we could pull the choke out part way and it run good. I started putting carb cleaner in my gas and after a few tanks the mower runs fine now. don't know if this would work on your carb or not. it would be better just to clean the carb.
sherman


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## shore warrior (Apr 5, 2015)

sherman51 said:


> sounds like your high speed jets are partly stopped up in the carb. my brother bought a 65 hp evinrude motor many yrs ago. it ran good at idle. we took it to dale hollow and jumped in the boat and took off. when he hit the throttle it would die. we tried putting gas in the carb at the same time he hit the throttle and it ran good. I tore the carb down at the dock and the high speed jets was completely clogged up. I took a piece of wire and cleaned the jets. then went back out and it run like a scalded dog.
> 
> my lawn mower was doing the same thing your motor is doing. at full throttle it ran real rough. we could pull the choke out part way and it run good. I started putting carb cleaner in my gas and after a few tanks the mower runs fine now. don't know if this would work on your carb or not. it would be better just to clean the carb.
> sherman


Thanks for the info. I am going to try and get into this little carb and check the jets out tomorrow. I been running Sea Foam through it since I got it. But maybe the jet is to gummed up for that to clean it.


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## shore warrior (Apr 5, 2015)

All my fuel hoses are black on the motor, fuel tank hoses are gray.


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## shore warrior (Apr 5, 2015)

Motor is a 1996 just looked.


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## sherman51 (Apr 12, 2011)

let us know how the carb clean works out for you. if a small piece of gas line came loose and got in the carb that could be the problem also. if the carb clean doesn't help you might want to change the gas lines on the motor. I have a old inline 6 115 hp merc that was giving me fits and the inner lining of the gas line had separated and was blocking the fuel flo. but it didn't want to idle or run at high rpm's. just some thoughts.
sherman


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## chatterbox (Jan 7, 2013)

Every post here is spot on. Ethanol is nothing but problems. We have to learn to deal with it though. It can be done, but costs more than before. Please read post in Boats & Motors about ethanol free gas.


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