posted 02-22-2004 11:00 AM ET (US)        

I would like to get a quality filter of small size with a clear bowl and think I want to go with something like this mounted on the transom in the splashwell.

www.marinefilters.com

Is there an ultimate recommendation on one that fits good in that area of the boat? Also, is the final word to mount the bulb betweeen the filter and the engine? There seems to be some debate on this topic.

posted 02-22-2004 01:08 PM ET (US)            

A middle course is to use the mounting bracket/fuel manifold from Mercury or Tempo and get the first replacement filter from RACOR with the bowl. Here is why:

The Mercury or Tempo mounting bracket/fuel manifold has four ports, two inlets and two outlets, so it works well with dual tank feed lines and dual engines. The RACOR manifold only has three ports. (I am not sure how they are arranged, either as dual inlets/single outlet or vice-versa.) It is not as versatile in a dual tank or dual engine situation. Of course for the really cautious, you'd get dual filters so the manifold problem would not be a concern.

There is also a stainless steel mounting bracket/fuel manifold available, too, and that is recommended for salt water use if the assembly is mounted in the open splash well or cockpit. I think that comes from TEMPO.

You can use the $7 replacement filter from Mercury or you can go with a more expensive $25 RACOR element that is sized to fit the Mercury manifold. I'd recommend the Mercury manifold because you are going to be able to buy some filter element to fit it just about anywhere on the planet. If you get something more exotic you won't find the replacement element at WALMART when you need one in a hurry.

The RACOR filter is nice because you can see the water that has been accumulated in it and filtered out. It can be drained and discarded. Perhaps you can keep using the filter longer without discarding it. I think once you get the plastic bowl you can just buy the elements, too, and save money.

The disadvantage of the plastic bowl is it can break. I don't know if it meets all the regulations for inboard boats or not when used with gasoline. I think it does for diesel.

As for where the primer bulb ought to go, that is a matter of some discussion, but ironically while you were posting this article I was just finishing a reference article on that topic, so please visit it for my opinion.

http://continuouswave.com/whaler/reference/primer.html

It has been seen that the primer goes before the filter, notably here:

http://continuouswave.com/whaler/cetacea/cetaceaPage10.html

posted 02-22-2004 02:09 PM ET (US)            

Now that I am older with kids I try to buy the best possible equipment when it comes to safety and reliability [SOSpenders, Racor filter, Boston Whaler :-) ]. Even though other filters will work great I will feel better with a Racor in the boat!

jimh...when I replied to the post this morning the time stamp was stamped for 2000...

http://continuouswave.com/ubb/Forum4/HTML/000026.html

posted 02-22-2004 07:51 PM ET (US)            

Both of the manifolds on my 27 have the four port arrangement so they must be OMC or Tempo manifolds, not Racor. The thought never occurred to me that the four ports were provided to enable twin engines to be connected to a single filter or separate tanks. I always thought the four port arrangement was provided to allow mounting flexibility for the manifold by providing flexibility in plumbing, i.e., (1) in and out from the left, (2) in from the left out from the right, (3) in from the right out from the left, or (4) in and out from the right. While I suppose two engines could be connected to this filter or two fuel tanks or both tanks and engines, I think it would be downright stupid not to have each engine draw fuel through its own filter and separate fuel line just to save 40 dollars initially and then 7 to 14 dollars per season for the extra replacement filter element.

posted 02-23-2004 01:02 PM ET (US)            

As explained to me, the issue is not so much starving of fuel if both engines are running, but the risk that if one engine is off, the running engine may draw from the stopped engine's feed line. If there is any break in the fuel line or a defective (leaking check valve in the) primer bulb, this is a possibility. Then, when you go to start up the stopped engine, you'll have either to reprime or worse, an airlock of some kind. For a carb'd engine, not a big deal, but for a FI engine, could be problematic. Where a single pickup feeds a main & kicker, some kind of check valve is to be installed in each engine's feed, after the lines split.

Also as Peter notes, the fuel/water filter head I have (Mercury kit, p/n 35-802893A 4) has four ports, configured for in/out from either side, apparently for plumbing flexibility, not necessarily to feed two motors from the single filter.

One other item--Mercury's instructions on the Optimax are to remove any fuel flow restrictions such as external fuel/water sep filters or shut off valves. The Opti 225 (and the old Laser EFI) have under-cowl fuel/water sep filters wired into the alert systems. Annual replacement is recommended. On installation, the dealer removed the original external fuel/water filter and plumbed direct to the pickup. I'll use fuel/water filter for my kicker going forward.

posted 02-23-2004 08:49 PM ET (US)         

As for JimH's comment that this provides a single failure point, that's easy to overcome by carrying a replacement filter, which I do. The Merc filters are small, economical to buy and easy to stow. A water separating filter is really a quite simple device.

posted 02-23-2004 09:11 PM ET (US)            

I am looking at brass fittings in the West Marine catalog designed to connect two tanks...do these fittings require you to run off of one tank or the other? Or do they allow you to run off of both tanks at the same time? I would like to run off of both tanks at the same time if this is possible, assuming the tanks would remain evenly full. Can someone help me with the best way to hook two tanks to one engine?

Thanks

posted 02-24-2004 08:28 AM ET (US)            

To the extent that the filter is a single point of failure, it will shut down both power plants, not just one. That could be a significant problem in some operating situations than if just one engine shuts down due to a filter failure. In my view, using a single filter in a twin outboard application cuts against the redundancy philosophy of twin outboards. Of course, if you take the redundancy philosophy to the extreme, you should also have dual tanks.

posted 02-24-2004 09:10 AM ET (US)            

You could argue that with dual engines, dual filters, and dual feeds (from a common tank), you ought to construct a manifold and valve arrangement so that each feed could supply either filter, and also allow each engine to draw from either filter output. With this arrangement, you could keep both engines running even if one filter or one tank feed went bad.

But then the single tank is a point of failure, so I better get dual tanks and each with dual feeds and dual filters in a manifold so I could run either or both engine from any combination of tanks, feeds, and filters.

At some point, it is reasonable to keep it simple.

posted 02-24-2004 09:00 PM ET (US)            

Thanks again,