Replacing water seperator/filter; what to bring to the boat?

[tmh]

I am working my way through things that may be causing an approx. 10% power reduction and tomorrow I'm going to replcae the water seperator.fuel filter. I have a canister (looks like an oil filter) water seperator/fuel filter on my merc 305 (1985) but I don't know exactly what filter it is. I have read on other threads that it will be full of fuel, etc. so I plan to remove it with a bucket under it. Then, I will take it to a parts shop (the marina OR an auto parts store nearby if that's OK) to make sure I get one that will fit.

When I put the new one on, do I need to lube it with oil at all? Do I fill it with gas from a gas can before installing? What else should I take to do the job?

Also, I read here somewhere that maybe it's not a great idea to have a low-micron filter/water sep combo then another in-line filter before th fuel pump. I don't know if this canister is also a low-micron filter, but if it is should I use a different one for the new one? I think the person who sold me the boat said it's a water sep and "nice fuel filter" but I will check when i get down to the boat tomorrow.

In summary:

1. Brief procedure for replacing water seperator.
2. What type filter to put on - can an auto parts store do the trick?
3. Any other fuel line thins I can check that could cause 10% power loss but still fairly smooth running engine?

 

[Reel Poor]

Re: Replacing water seperator/filter; what to bring to the boat?

If it's a spin-on filter the seirra 18-7844 (short filter) or the 18-7845 (long filter) should fit. Available at NAPA. Prefilling never hurt anything. No need to lube.

Oil filter wrench or a strap wrench should do the job.

Depending on the carb your running there may be a filter at the fuel inlet of the carb.

One 10 micron fuel/water separator is sufficient.

 

[Coors]

Re: Replacing water seperator/filter; what to bring to the boat?

Reel. I thought that you lubed
the gasket, so you can get it off the next time...

 

[Gary H NC]

Re: Replacing water seperator/filter; what to bring to the boat?

Reel. I thought that you lubed
the gasket, so you can get it off the next time...

Some people do and some don't. It does not get hot like an oil filter so it should not really matter.

I always fill my filter with Seafoam to give the engine a little cleaning...

 

[WAVENBYE2]

Re: Replacing water seperator/filter; what to bring to the boat?

I would use a coffee can or some thing under the filter, just saves time on having to clean the bilge area. I put a little oil on the seal gasket its what it said to do on the box it came in, after you put on the filter check for leaks, better to be safe then sorry...Pat

 

[Coors]

Re: Replacing water seperator/filter; what to bring to the boat?

Some people do and some don't. It does not get hot like an oil filter so it should not really matter.

I always fill my filter with Seafoam to give the engine a little cleaning...

On my new high tech 1988 OMC, the filter is in front, and the computer spins it off when you hit f2.

 

[njlarry]

Re: Replacing water seperator/filter; what to bring to the boat?

Hi Gary, I like your idea of adding the seafoam but I thought it was the general opinion on a previous post not to use straight carb cleaner in the filter on a gas engine least it break up and lodge deposits elsewhere in the carb. Also will the engine run on pure seafoam? Do you stop the engine and let it soak before running the remainder through?

 

[tmh]

Re: Replacing water seperator/filter; what to bring to the boat?

Thanks guys. I'm good to go I think.

I am wondering about the seafoam also...interesting idea. Maybe mix in some gas with it or something?

 

[jspringator]

Re: Replacing water seperator/filter; what to bring to the boat?

WalMart sells a Quicksilver filter (Mercury) that shows as a direct replacement for a Sierra 18-7846, which according to Sierras website, is the replacement fuel filter for OMC Cobra.