Do i have fuel issues? Or idle issues?

Joined
Jul 10, 2011
Messages
7
i have a '99 mercury saltwater 115 and it will not idle. i have replaced fuel lines, fuel filters, primer bulb, the fuel line connections to the engine and the water separator. Also i have gone thru the carbs and cleaned those. It starts up great but it will not keep running. i can rev it up and it will run at higher rpms for a lot longer but it to will end up shutting down. i would say it run this way for several mins. the fuel is from late last year and it does have startron and seafoam. thanks for any help!
 

sutor623

Rear Admiral
Joined
May 23, 2011
Messages
4,089
Re: Do i have fuel issues? Or idle issues?

Have you tried to adjust the idle jet setting? It sounds like you need to richen it up some.
 
Joined
Jul 10, 2011
Messages
7
Re: Do i have fuel issues? Or idle issues?

No Sir, where exactly is that screw. do i adjust the same on all carbs?
(first time boat owner)
 

sutor623

Rear Admiral
Joined
May 23, 2011
Messages
4,089
Re: Do i have fuel issues? Or idle issues?

How many cylinders/carbs does this model have? Is it a pro xs, or what model?
 

sutor623

Rear Admiral
Joined
May 23, 2011
Messages
4,089
Re: Do i have fuel issues? Or idle issues?

You may also need to perform a link and sync. Check the articles here on the forum and it will guide you on how to do it. There are a lot of great reads on here that more people should read before diving head first into their motors.
 

1nebel0

Chief Petty Officer
Joined
Nov 28, 2005
Messages
512
Re: Do i have fuel issues? Or idle issues?

Its a 115 and you only have idle screws on two carbs as this motors idles on two carbs and than transitions to the other two which could cause you some problems if the motor is not lync and sync along with the correct accelerator pump not setup correctly..These motors are not the best idleing motors but my bet is your carbs are too lean...back out each screw 1 1/2 turns from lightly seated position and let us know if that does it....
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Do i have fuel issues? Or idle issues?

Before you start messing with adjustments try testing a couple of simple things. You know, the old 'KISS' principle.

Disconnect the fuel hose to the carbs and crank the motor watching to ensure a strong pulsed flow, then temporarily install that hose with a clear hose, start the motor and watch for any air bubbles passing thru which would prove air sucking into the fuel system somewhere between the fuel pump and tank.

Be SURE to remove that clear hose once finished with repairs as clear hose is NOT rated for fuel.
 
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