two motors 1 water/fuel separator?

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whistler

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I run two motors of different brands with two remote tanks. Since a water/fuel separator has two inlets and two outlets can I run them both through one separator? I suppose if they have a different size fuel hose I would need to get the separator to fit the larger diameter hose and reduce it down for the smaller one? Or would it be best since they are both 4 strokes. Can I use one gas can and hose to the separator and then run the two hoses with proper motor fittings to the different brand motors.
 
Very good question. What size motors?

Are you talking about running the motors at the same time (twins). If not, there should be no problems. The other hose would basically be dead while using the other one.

I put twin 300hp Suzuki's on a boat with a single water/fuel and ran into a fuel starvation problem. The mechanic said that I was lucky I didn't burn up the fuel pumps. The fuel/water separator is capable of running two motors if you size the supply hose correctly. I increased the size and had no more problems.

I would be interested to hear what other mechanics say about this.
 
Specknreds said:
Very good question. What size motors?

A 9.8 kicker for small lakes and a 40-50HP for running. I actually haven't purchased this one yet but am shopping around.


Specknreds said:
Are you talking about running the motors at the same time (twins). If not, there should be no problems. The other hose would basically be dead while using the other one.
Only one at a time as mentioned above.

Specknreds said:
The fuel/water separator is capable of running two motors if you size the supply hose correctly.(snip)

I would be interested to hear what other mechanics say about this.

If one of the motor used a different size hose I would get the larger separator to fit the larger motor/hose then reduce it down on the small motor/hose size.

What about the 2 outlet hoses to the motor with 1 tank in the second scenario?
 
I got you now. You should be fine with the current hose set up. If it were me, I would just cut the hose going to the bigger motor. Install the w/f separator and then tie you kicker hose to the other outlet on the separator. You probably already have all the parts needed except for the separator.
 
Sounds like you have the right plan in mind. Just in case that doesn't work, you could put a fuel selector switch prior to the water separator. I have a similar setup to this, but only one motor (two tanks.)

KRS
 
If you run both motors off the the same water/fuel separator you may want to place a check valve in the lines on the outlet side of both to keep from sucking fuel from the other outlet side with just one motor running. The separator may have check valves built in, I am not sure. Its just that you want the fuel coming from the tank and not from the supply line of the other motor.
 
KMixson said:
If you run both motors off the the same water/fuel separator you may want to place a check valve in the lines on the outlet side of both to keep from sucking fuel from the other outlet side with just one motor running. The separator may have check valves built in, I am not sure. Its just that you want the fuel coming from the tank and not from the supply line of the other motor.

Interesting thought Hmmm? Let me think about this, the water/fuel separator has two inlets and two outlets. What would be the purpose of this arrangement if not to run more than one Motor, tank or combo? Thus if it is designed for that purpose and the sucking of fuel from the other motor is a concern I would have thought the designers (engineers) would have figured that in. I would agree that it seems a concern and it certainly wouldn't be the first product that hit the market poorly thought out! :oops: If a check valve would be needed what type style are we suggesting. Could placement of the fuel bulb between the separator and the motor be sufficient. Thanks to all who have jumped in an offered thoughts! =D>
 
I think the extra inlet and outlet are to make mounting easier.
 
lckstckn2smknbrls said:
I think the extra inlet and outlet are to make mounting easier.

Are we speaking of the extra inlet and outlets allowing a mounting position that would maybe eliminate an interference problem between the separator and another item on the boat or motor? Is so not to start an argument or dispute that but I would think the manufacture would be better served by providing an extra angled fitting or casting the separator with the inlet/outlet coming out at a different angle as opposed to the current position of side by side? Would provide lots more flexibility. Just my thoughts and you could be 100% right and I could be wrong again!
 
Hmmmm, this is a very interesting topic. My twin 9.9s are using a single fuel line through the single primer bulb and then the hose branches off using what looks like a standard Tee (no check valves). Sometimes a single engine at low speeds runs a little rough like it is losing prime, and the bulb feels weird too. Duh! I never thought about it, but mine should work better with separate primer bulbs. I'm planning to run mine through a separator as well, so I will probably make the change when I install that. Thanks for the post! For you, using two separate tanks won't be necessary, but you could hook both up to the separator and let one be a reserve. I think you will need a shutoff valve upstream of the separator on both tanks though because it all goes to the same place once inside, and the engine that's running will pull from either or both tanks. If one tank runs out of gas you'll need to turn it off, so it doesn't suck air and turn the other one on.
 
benjineer said:
Sometimes a single engine at low speeds runs a little rough like it is losing prime, and the bulb feels weird too.

It could be because it is pulling fuel through the float valve on the the other engine. If one engine is not running, the float is dropping with the suction on it from the one that is running.
 
whistler said:
lckstckn2smknbrls said:
I think the extra inlet and outlet are to make mounting easier.

Are we speaking of the extra inlet and outlets allowing a mounting position that would maybe eliminate an interference problem between the separator and another item on the boat or motor? Is so not to start an argument or dispute that but I would think the manufacture would be better served by providing an extra angled fitting or casting the separator with the inlet/outlet coming out at a different angle as opposed to the current position of side by side? Would provide lots more flexibility. Just my thoughts and you could be 100% right and I could be wrong again!
Yes to avoid an interference problem but then I could be wrong.
 
I have worked on many boats with twins, from my last boat with twin 225 Johnsons, to a 38' egg harbor with 600 hp diesels. ALL had separate filters. Why? Well, something like 90% of issues on the water arise from fuel, and especially now with ethanol percentages sneaking upward, this is not going away. It sounds like you would have the ultimate in safety if you ran two separators...two engines capable of getting you home from different fuel sources.

I was bringing home a 35' Mainship from the Bahamas, going into King's Bay Georgia when one of the engines crapped out...the issue? Bad fuel from a Bahamian dock. We had several sets of extra filters onboard, but could not stop to change the one that was clogged, because a Boomer sub was coming out at the same time. we limped out of the way, changed the filter and made it home. If we had had only one filter, then we would have been up a creek, so to speak.
 
msumoose said:
I have worked on many boats with twins, from my last boat with twin 225 Johnsons, to a 38' egg harbor with 600 hp diesels. ALL had separate filters. Why? Well, something like 90% of issues on the water arise from fuel, and especially now with ethanol percentages sneaking upward, this is not going away. It sounds like you would have the ultimate in safety if you ran two separators...two engines capable of getting you home from different fuel sources.

I was bringing home a 35' Mainship from the Bahamas, going into King's Bay Georgia when one of the engines crapped out...the issue? Bad fuel from a Bahamian dock. We had several sets of extra filters onboard, but could not stop to change the one that was clogged, because a Boomer sub was coming out at the same time. we limped out of the way, changed the filter and made it home. If we had had only one filter, then we would have been up a creek, so to speak.

WOW some story there, How does one know that a sub is in the area? Is it their duty to warn you or your duty to monitor them somehow? I remember a news report some time back about a sub surfacing under a boat. It wasn't pretty! Back to the subject I don't do any offshore running only small lakes or backwater creeks off of a river. Boat is a flat bottom boat used for fishing, hunting, trapping etc. what ever I want to do. I do plan on carrying an extra filter for an emergency and I purchase all my gas off the water as I usually don't need more than a tank at a time. I feel two separators while no doubt is the best option would probably be overkill for me and with the limited space in that area difficult. Is there a brand of filter/Separator that while does a good job the filters are more wildly obtainable. I live in a rural area with no marinas nearby so a separator that uses several brands of filters that might also be available at a parts house would be a plus. Thanks for your info! =D>
 

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