4.3 spin on water seperator

[gtfireftr]

I am going to change the water separators on my 4.3's....
I am thinking I may have a problem re-priming the fuel system with such a large empty filter...
Is it necessary, and appropriate to fill them prior to installing them? I don't want to burn out a starter trying to fill the filters???

 

[bspeth]

I always fill them,and she fires right up.

 

[Alumarine]

If you only run the starter for 15 seconds and then let it cool for a minute then no need to worry about burning them up.

 

[Bondo]

Is it necessary, and appropriate to fill them prior to installing them?

Ayuh,..... Is it Necessary,..??..?? Usually not,....

Is it Appropriate,..??..?? Sure, if you can spin it back on without dumpin' gasoline into the bilge,....
The explosion hazard is much higher than the limited wear on the starter,....

If it's a bad place to get to, 1/2 full is better than empty, but it oughta work empty as well,....

 

[HT32BSX115]

Ayuh,..... Is it Necessary,..??..?? Usually not,....

............. it oughta work empty as well,....

I always install mine "dry".
There's really no need to fill those filters if your fuel pump is not faulty.

I just pull the carb flame arrestor and pour a little splash of gas into the carb and start it up. You might have to do it twice but there's no extended cranking necessary and the filter fills almost immediately.

 

[Leardriver]

In a fuel injected boat, you can cycle the key to on 2-3 times, and the electric fuel pump will have it filled before you turn it over.

 

[Fun Times]

What year are your 4.3's? Are they carbureted or EFI's?

If they are newer models with Electric Fuel Pumps, It's considered a better idea to pre-fill the filter till about 3/4 full to help slow prolonged engine starting/cranking as both the fuel pump and engine starters start to become considered compromised internally in shorter periods of time as Mercruisers recommendations are to not let the fuel pumps run dry for longer than 10 seconds as noted in a service bulletin about fuel pump warranties quoted below.
High pressure fuel pumps are considered to have low pickup suction as they are more designed to push fuel vs suck fuel up.
Should an engine from mercruiser have the catalyst exhaust system, it is best not to let the engine run lean on fuel.

Troubleshooting Models Affected All MerCruiser V6 and V8 carburetor, EFI and MPI gas engines. Situation Mercury MerCruiser receives electric fuel pumps returned for warranty that function properly when tested (No Trouble Found). Engines that are not run for extended periods of time or are placed in storage with untreated fuel are at risk of forming fuel gum. The accumulation of fuel gum can seize electric fuel pumps, which typically results in the replacement of a mechanically sound fuel pump. NOTE: Boost pumps used on EFI or MPI models are the same low pressure pump used on carbureted models. The pumps used to pressurize the EFI or MPI system is a high pressure pump. IMPORTANT: Electric fuel pump can be run dry for 10 seconds. Do not run the pump dry repeatedly or internal damage may occur.

Strange fuel delivery problem 2002 Mercruiser 5.0 MPI ...

 

[JoLin]

You shouldn't have to crank the engine to fill the canister. If you want to put 'some' fuel in the filter it won't hurt anything, but you shouldn't have to do that.

Start the engine briefly and shut it off. Change the filter, Restart the engine. There's enough fuel still sitting in the line to start the engine. The filter will fill before the engine stalls.

My .02