Should I install a water/fuel separator

[izoomie]

Just bought a 2007 Merc 90hp 4 Stroke EFI on my fish/ski. The motor has two fuel filters in it but there is no water separator on the rig. I never worried about it with my 1988 johnson 2 stroke 90hp but I wonder if this more modern engine with fuel injections is more susceptible to damage from water in the fuel.

 

[Bob_VT]

Re: Should I install a water/fuel separator

It might be worth the insurance and piece of mind .......... won't hurt anything water seperator - iboats

 

[bassman284]

Re: Should I install a water/fuel separator

The first filter in the fuel line should be a water separating filter unless a previous owner took it off for some reason. It should be on a bracket attached to the block upstream of the low pressure fuel pump. It would have a sight glass on the bottom. Do you have you owner's manual. should be a picture of it in there.

 

[bassman284]

Re: Should I install a water/fuel separator

Here's a scan from my manual. This is on a 2001 60hp 4 stroke.



A little rough but should give you an idea where to look and what it looks like.

 

[rickdb1boat]

Re: Should I install a water/fuel separator

There is no built-in separator on the 90HP model. You can add one inline from the fuel tank to the engine. It's not really recommended by Mercury, but I've had one on mine since new (2007) and it works fine..

 

[robert graham]

Re: Should I install a water/fuel separator

I'm of the opinion that the addition of a water/fuel separating filter is the one best preventive maintenance item thus far. Yamaha and Racor both carry an extensive line of filters, but I've used the Walmart/Attwood unit ($28) for years....it's simple, cheap and easy to install....good luck!...

 

[achris]

Re: Should I install a water/fuel separator

Can't have too many filters, especially on injected engines.

Just make sure the fittings aren't over-tightened, crack the housing and cause an air leak.

Chris.....

 

[bilge rat jim]

Re: Should I install a water/fuel separator

I've always considered a water separating filter an essential on any EFI outboard. A 40 buck filter between the tank and the outboard is cheap insurance when you consider the cost of replacing a $275 fuel pump or a set of injectors at $500. Personally, I like the filters that have the clear canister, then you can visually monitor your fuel for signs of water.

 

[limitout]

Re: Should I install a water/fuel separator

water/fuel separator - don't leave the dock without one

 

[Fleetwin]

Re: Should I install a water/fuel separator

Absolutely. You can buy a whole kit for about $40.00. Replacement Spin On filters are about $10. Replace once a year and go.

 

[bassman284]

Re: Should I install a water/fuel separator

There is no built-in separator on the 90HP model. You can add one inline from the fuel tank to the engine. It's not really recommended by Mercury, but I've had one on mine since new (2007) and it works fine..

Seems odd they wouldn't recommend it for the 90 but have it as standard equipment on the 40-50-60.