Fuel filter selection

[Randyg123]

Any tips on selecting an in-line fuel filter?

Type preferred?
Brands to select/avoid?
Location in fuel line?
Fixed-mount v. loose?

'75 135HP Johnson

Thanks in advance

 

[ezeke]

Re: Fuel filter selection

Water separating filters work from gravity, so they should be mounted in a fixed location where they are not subject to movement from tilt and trim etc.

All other things being equal, the bigger the filter, the more water it can separate and the more debris it can filter before clogging.

The ideal filter can be drained from the bottom, and you can see the water through the plastic base. These are expensive, but arguably the best.

Your 135 uses a substantial amount of fuel and will be best protected by a full-sized water separating filter.

I like the filter as close to the tank as possible and above the top of the tank in case of a leak so that fuel will not be siphoned from the tank.

 

[tashasdaddy]

Re: Fuel filter selection

i like mine in the motor well if there is room.

 

[dajohnson53]

Re: Fuel filter selection

I hope this isn't a thread hijack, but I think it's a related question.

have recently installed a new engine. Old engine was an 80's V6, new engine is a 90's V6. I have retained the existing water separating filter, a Racor clear bowl S3214. It's always worked great, and like Ezeke, I recommend this system, or at least a cannister type water separating filter. I've always used them in some form or other.

My question is this: my old engine had a small OMC inline gas filter inside the cowling, between where the fuel line enters the cowling and the fuel pump. My new engine does not have this filter. I haven't been too concerned since I do have the water separator. But I went ahead and purchased one of the small filters intending to splice it into the fuel line inside the cowling. I guess I should have asked this question earlier, but is this second filter really necessary? Interestingly, I believe both the factory owner's manual and service manual refer to this filter even though it is not installed in my engine. It could be that previous owner did not use one because he also had a water separating filter.

 

[ezeke]

Re: Fuel filter selection

My concern on the extra filter would be that it places unnecessary additional resistance on the fuel flow. The oil tank has its own internal filter.

 

[SKEETR]

Re: Fuel filter selection

Interesting, I was wondering the same thing. Especially since the guy I bought my boat from neglected to buy the metal one req for my inboard jet.
I was about to purchase one to replace existing.

 

[Randyg123]

Re: Fuel filter selection

I am not too convinced I need to go to the extra expense of a fuel/water separator in my situation. Mostly because I only use a six gallon tank and as you all know, with this 135, that doesn't last very long. Needless to say, I fill the tank just about every time I go out. If the gas in the tank gets older than a month or so, I just give it away to someone I know that needs it, so the tank gets emptied completely several times a year. And here in OK the humidity is not a year-round issue.

I think 99% of the risk I am trying to prevent is getting some particles into my carbs. I understand the screen at the fuel pump should prevent anything large from reaching my carbs, but does an inline particulate filter trap anything else or is it just preventing the filter on the pump from getting clogged? I would expect the inline unit would filter out finer particles than the screen at the pump, but would these smaller particles create problems in the carbs anyways?

 

[Randyg123]

Re: Fuel filter selection

Wow...I thought for sure I'd get a lecture from someone about 'going cheap'! he, he

But seriously, any thoughts on the simple inline particulate filters. Are they a good idea or simply a waste of time and $$?

 

[tashasdaddy]

Re: Fuel filter selection

your fuel pump has a built in filter, remove the center screw, you will see a screen behing it. watch out don't loose the Oring.

 

[ezeke]

Re: Fuel filter selection

I don't think that a filter designed for use with gasoline/oil mix in a marine environment is a waste of money. I always used them, never rebuilt a carburetor on my 1973 135 and only once on the 1976 115 - because the hoses fell apart.

 

[goldstem]

Re: Fuel filter selection

the filter on the fuel pump is a screen that only catches the grossest of impurities. I have had trouble with stuff in a 6 gallon portable - once
jamming the inlet valve on a johnson 40 wide open. get the racor filter. it is money well spent, and will prevent lots of carb problems. i have them on all my boats, and the boats that our sailing club uses (all fed by portable tanks) and our carb problems have been zero ever since. the only hassle has been if you run the whole system dry (happens at our sailing club) getting the system re-primed can be a hassle.

 

[dajohnson53]

Re: Fuel filter selection

Wow...I thought for sure I'd get a lecture from someone about 'going cheap'! he, he

But seriously, any thoughts on the simple inline particulate filters. Are they a good idea or simply a waste of time and $$?

I really think a water separating filter is almost essential, and it will only cost you about $10-$20 per year to replace after you get it installed.

But really it depends on how inconvenient it is for you to get disabled because of water in the fuel. I believe modern DFI engines can be ruined by water getting through, but that's probably not the case for you. If (a) the chance of water problems is low (which it sounds like for you) and (b) it really is more an inconvenience than a serious problem, then you'll be fine with the standard little in-line filter. You should buy one that is made for outboards. I always just use the OEM ones because they're cheap and easy to find. I would definitely put some sort of appropriate in line filter on it though: why wouldn't you?