Water seperator for a 2 stroke and a 4 stroke auxillary motor

starjet

Recruit
Joined
Jan 27, 2009
Messages
4
Does anyone know if you can run two fuel lines thru the same water seperator. I want to hook up my main 2 stroke and an auxillary 4 stroke trolling motor. Do I need two seperate filters?

Maybe a dumb question but one line will have oil in the gas and the other line will be straight gas.

Does some opf the oil stay in a filter when a 2 stroke fuel goes thru it?
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,762
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

The filter will not filter out the oil.

You can not run 2 types of fuel into one filter, and expect them not to mix.
They will mix. You will have oil going into the 4 stroke, and not enough oil going into the 2 stroke.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,369
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

One of the benefits of running a oil injected two stroke
 

starjet

Recruit
Joined
Jan 27, 2009
Messages
4
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

So what you're saying is I need two seperate filter systems. I don't understand how oil mixes with the 4 stroke if the two stroke is off anf the 4 stroke is running off of a seperate gas only tank.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,137
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

So what you're saying is I need two seperate filter systems. I don't understand how oil mixes with the 4 stroke if the two stroke is off anf the 4 stroke is running off of a seperate gas only tank.

Ayuh,.... When ya switch tanks/ motors the gas in the filter, will be the wrong gas,...

The 4 stroke will smoke til it burns off,...
'n the 2 stroke may well seize, before the mixed gas displaces the straight gas,...
 

Home Cookin'

Fleet Admiral
Joined
May 26, 2009
Messages
9,715
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

also you weaken the back-up aspect of the smaller motor. Often motor failure is caused by problems in the fuel path, including a clogged or water-logged filter. Since you have to run two tanks anyway, spending the extra $15 for a second filter is worthwhile to keep the two systems independent.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

Since I'm human and I must assume you are too, Star, we make mistakes. The mistake to be made here is forgetting to switch tanks when going to the kicker and vice versa. Straight gas mistakenly running through the main 2 stroke will have you coming back here with questions and no good answers.

Spend the extra cash for for two separate water separators.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: Water seperator for a 2 stroke and a 4 stroke auxillary motor

If you buy good quality fuel and consume most of it throughout that outing, no need to install a water separator filter specially if boating with small to medium portable engines. In the long run could develop fuel pump diahragm stress issues, due to being thin made and with more pumping work than without a water separator filter. Never have used one and don't plan using one.

The 4 HP engine probably has an internal fuel tank and can't possibly install a water separator filter ?

Happy Boating
 
Last edited:
Top