09 Mercury 15hp Outboard- no gas getting to priming bulb on motor.

txriver

Recruit
Joined
Sep 15, 2012
Messages
2
OK, first post, just joined. I just bought an alum. boat with a 09 mercury 15hp tiller style, no e start. Was out last weekend and while running full out the motor ran rough for a few seconds then totally died. By holding the choke lever out most of the way I managed to limp back to the boat ramp. Got home and tried to figure out the problem, found fuel pickup line inside tank a little too long and had a pretty good crimp but not totally blocked. Then i noticed the primer bulb doesnt seem to be filling, the one on the engine hooked to the carb not on the fuel line. Checked bulb by disconnecting and holding my finger over the hole and it held suction in the bulb. no obvious damage to the line. I did these things and the motor now runs but still absolutely no gas getting to the primer bulb on motor. All advice or ideas appreciated.
 
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Maxz695

Guest
Re: 09 Mercury 15hp Outboard- no gas getting to priming bulb on motor.

Is the fuel pump before the primer bulb? The diaphram may have a tear or puncture. Also check all the fuel line for a crack. The primer bulb is pulling in air from somewhere
 

txriver

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Joined
Sep 15, 2012
Messages
2
Re: 09 Mercury 15hp Outboard- no gas getting to priming bulb on motor.

yes, the gas line goes to the fuel pump and the primer bulb has only one hose that goes to the bottom of the carb, I am assuming its the accelerator pump. It was running perfectly though, do you think the diaphram in the accelerator pump could have gone out so suddenly while under way? My understanding from my dirtbike carb experience is that the accelerator pump just draws in a little gas to the carb to get it started. I agree i have an air leak somewhere, I just cant figure out where, Im not seeing a fuel leak anywhere. I started the motor and while running disconnected the outlet hose from the fuel pump to make sure it was pumping good, it was squirting gas like crazy until the fuel supply in the carb ran out and died. Im open to any ideas of stuff i can check...
 
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Maxz695

Guest
Re: 09 Mercury 15hp Outboard- no gas getting to priming bulb on motor.

I,m not firmiliar with your engine I,m sight unseen but there are only so many things that it can be. True the primer bulb like a weed wacker or chainsaw pumps a slight bit of gas to start the engine. The are gravity fed and need no assistance to get fuel to the carb. The marine engine needs the fuel pump to pull the gas from the tank and push feed it through a filter and then the carb. (Normally) The fuel pump cannot pull gas if there is air being pulled n somewhere and it will not nessecarily leak feul at the point of the source. The diaphram in the fuel pump can stretch to the point of being totally unfunctional. If it hasn,t been changed in many years it may also become hardened and crack or tear which would cause it to fail in both pulling and pushing abilities. If there is fuel coming out of the fuel pump then your problem lies between the hose and or filter going from it to the carb.There may be a restricion inside of the carburetor. On some carburetors they have a screen where the fitting for the fuel line goes into the carb. I would take the carb apart and clean it really good with carb cleaner. You may be getting a bit of gas in the carb but not a steady flow needed to fill the bowl
 

toyn2much

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Joined
Sep 16, 2012
Messages
5
Re: 09 Mercury 15hp Outboard- no gas getting to priming bulb on motor.

I just fixed this on my 2007 9.9. The enriching valve on mine was totally fouled. I noticed this because while the motor was running I manually activated the valve(it affects choke too) and there was no difference in how the motor ran. The primer bulb draws fuel from this valve. I removed carb and cleaned with brake cleaner and pipe cleaners. Also, the hose running from bulb to carb had a small pin hole in it.

Runs like a champ now.... except for my water flow issue.
 
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