Fuel pump down

[Phillips2124]

Hey boat freaks maybe y’all can help. I have a 2007 opti 2 stroke. My fuel pump that supplies fuel/ water filter will not pull fuel. I take out filter I pump ball it fills case but I turn Motor over pump will not pull fuel for supply. Just rebuilt it thinking that was issue but no. I took off air supply line and with my finger I feel suction pressure. What you think ?

 

[Scott Danforth]

Get a new fuelpump

 

[flyingscott]

Isnt that pump electric and controlled by the emm.

 

[Chris1956]

Optimax's have two high pressure electric fuel pumps. One for running and both are used during starting. They should run when key is turned to run, before starting.

Optimax is a different animal, compared to a conventional 2 cycle motor. I would recommend a factory service manual, and a set of pressure gauge for the fuel and air rails.

 

[tlh 178]

try this, turn key on, within the 1st 10 seconds. move your shiftier from neutral to forward 3-5 five times. this will activate the priming on your fuel pump. you should hear your fuel pump kick in and it will run for atleast a minute or two, so don't freak out when you hear your pump turn on, as it will stay running. i just went thur this last month as i pulled fuel rail and injector to be cleaned. hth.

 

[tlh 178]

i have an optimax as well!

 

[tlh 178]

you can find your manual at the top of this merc forum. its the top sticky, click on boat info, goto merc section and find opti. the priming process can be found on page 3C-8.

 

[Faztbullet]

That for oil pump priming not the fuel pump.... I think the poster is saying he rebuilt the mechanical pump but the low pressure pump (elec) will not pull fuel. This is possibly because high pressure pump is not running so test to see if working. Also need HP....

 

[tlh 178]

That for oil pump priming not the fuel pump.... I think the poster is saying he rebuilt the mechanical pump but the low pressure pump (elec) will not pull fuel. This is possibly because high pressure pump is not running so test to see if working. Also need HP....

my motor would not start until i did the priming, wouldn't even fire. as soon as i primed it, it fired right up. as posted above those opti are a different breed.

 

[Phillips2124]

My first time posting didnt realize I had to be logged in to see notifications i was waiting on emails.Wow thanks for all feedback. This motor has three fuel pumps. One outside attached to fuel pump module( mechanical powered by crankcase pressure/suction I believe like a weed eater pump) no electricity to it. This pump pulls fuel from fuel tank and feeds fuel water separator where the filter is. Theres also two electric high pressure pumps inside module, these are fine. My problem is with that outside air driven pump that feeds the module.I can pump my ball and fill entire module the motor would start for a while then itll stop. Ill open bottom drains and take out fuel/water filter the module is empty. Basically the motor took all the fuel and nothing was feeding the module ( the mechanical pump attached that does the feeding). Im no merc expert but i believe this is the way this space age motors fuel system operates.

 

[Phillips2124]

Faztbullet ok so "low Pressure" electric inside module pulls fuel? why is there a mechanical air driven pump outside attached to fuel water filter ?

 

[Phillips2124]

Optimax's have two high pressure electric fuel pumps. One for running and both are used during starting. They should run when key is turned to run, before starting.

Optimax is a different animal, compared to a conventional 2 cycle motor. I would recommend a factory service manual, and a set of pressure gauge for the fuel and air rails.

Gauges good idea!! But im not getting the fuel delivered there. I can push the tire air fitting thing on the fuel rail and no fuel at all. Push the air fitting i feel air. YES merc is different animal..The engineering is top notch but to me TOO engineered

 

[Phillips2124]

[No message]

 

[Chris1956]

Although I have never taken it apart, the mechanical fuel pump looks very much like a standard Merc V6 carb fuel pump. If it is similar, it is easily rebuildable. I just looked up a 2006 Optimax 150HPV6 fuel pump, and the kit is priced the same and looks the same as the one for my Merc carb V6.

You might rebuild it. You might get a service manual, as I think you need to break off some excess plastic stems on the check valves, if memory serves,

 

[Faztbullet]

The mechanical pump pulls fuel from fuel tank and fills VST. The low pressure fuel is sent to high pressure which goes to fuel rails. There is no priming of the fuel system just a purge off the Schrader valve on fuel rail. The check valves usually wrinkle/warp and cause pumping issues.The plastic stem you drive thru the plastic insert as its a rivet, not break them off...