Help: Water Seperator cause surge then kills

[johnredmond]

1999 Johnson 2-cycle 175. Runs great if I run the line with a regular fuel fillter into the gas tank. If I add a water seperator, within a minute after I throttle up, the alarm sounds, seconds later it surges back and forth, then dies. I've tried two different brands of water separator (Racor and Envinrude/Johnson), moved the placement, put on new filter. Same result. It is obviously the water seperator not allowing the full vacuum when it increases with throttle up, so it then starves the engine. My orofessional boat mechanic can't firgure it out.

Ideas anyone? If no solution, I'm just going to run it without the water separator. No choice.

Thanks

 

[bob johnson]

Re: Help: Water Seperator cause surge then kills

1999 Johnson 2-cycle 175. Runs great if I run the line with a regular fuel fillter into the gas tank. If I add a water seperator, within a minute after I throttle up, the alarm sounds, seconds later it surges back and forth, then dies. I've tried two different brands of water separator (Racor and Envinrude/Johnson), moved the placement, put on new filter. Same result. It is obviously the water seperator not allowing the full vacuum when it increases with throttle up, so it then starves the engine. My orofessional boat mechanic can't firgure it out.

Ideas anyone? If no solution, I'm just going to run it without the water separator. No choice.

Thanks

the sensor that monitors the fuel pressure, is probably bad...

is the hose really really big going into and out of the seperator...I wonder if that would give a pressure drop..

i know the my manual which covers the 150 and 175 ocean pro and runner series, has a section on the alarms and one is for fuel pressure..

what eve ris monitoring the fuel pressure is suspect I would guess..


you should be able to run a seperator on every motor

have your mechanic look into servicing the fuel componet bracket( if it is equiped )


bob

 

[johnredmond]

Re: Help: Water Seperator cause surge then kills

Thanks very much for your response.

Does the sensor/alarm itself shut down or physically affect the fuel flow to the engine. If so, does disconnectiong the alarm solve the problem. I thought that the alarm merely told you the problem, not physically itself do anything to the fuel flow.

Hose in and out of the water separator is standard 3/8".

What is a fuel component bracket.

This is an extremely frustrating problem.

 

[jonesg]

Re: Help: Water Seperator cause surge then kills

Before spending money on sensors, remove the anti-syphon valve at the fuel tank, its usually located in the elbow at the top of the feed pipe.
Remove from tank and knock the ball out so its free flowing.
They can get gunked up and become marginal, then if you add a water seperator and the alarm goes off.

Either that or eliminate the extra fuel filter.

Clean the fuel pickup screen too.

 

[bob johnson]

Re: Help: Water Seperator cause surge then kills

Thanks very much for your response.

Does the sensor/alarm itself shut down or physically affect the fuel flow to the engine. If so, does disconnectiong the alarm solve the problem. I thought that the alarm merely told you the problem, not physically itself do anything to the fuel flow.

Hose in and out of the water separator is standard 3/8".

What is a fuel component bracket.

This is an extremely frustrating problem.

some motors have a S.L.O.W. system.... when the overheat alarm goes off, it does something to limit teh motor to 2500 rpms

it COULD do the same for any alarm I imagine...


give jonesg's suggestion a try first.. its wont cost any money..

good luck

bob

 

[jonesg]

Re: Help: Water Seperator cause surge then kills

some motors have a S.L.O.W. system.... when the overheat alarm goes off, it does something to limit teh motor to 2500 rpms

it COULD do the same for any alarm I imagine...

I was wondering about that, too lazy to go downstairs and snag my manual though.

 

[bob johnson]

Re: Help: Water Seperator cause surge then kills

I am readig the manual for 60 degree eagle block motors..mine a 95, this book covers the V4 and V6 motors

they say the alarm for fuel restriction( only on V6) is a continuous tone at or near full throttle.


going to dig deeper about the slow mode

EDIT, the SLOW explanation says it is seperate from the warning horn system, and only applies to the temperature switches.

bob

 

[ezeke]

Re: Help: Water Seperator cause surge then kills

S.L.O.W. is isolated to the overheat switch by the blocking diode in the harness. Unless the diode is damaged, the fuel system alarms cannot reach it.

The vacuum switch on the fuel line also runs ahead of the blocking diode so that it activates the horn and sounds the constant alarm but does not reach the powerpack either.

This is all shown in the color wiring diagrams in the back of the appropriate factory service manuals.

 

[ezeke]

Re: Help: Water Seperator cause surge then kills

The pumps are not designed to overcome redundant filters. When you add the full sized water separating filters, the other gasoline filters are no longer needed . The oil tank has its own filter in the oil tank.

All fuel filters should be of design for and specifically rated for outboard motor use. Check the manufacturer's web sites for information. For example: http://www.teleflexsierra.com/Johns...ated-Products/dm/store_id.373--view_id.488121

 

[emdsapmgr]

Re: Help: Water Seperator cause surge then kills

You can test to see if you have a fuel restriction. The vacuum switch is set to sound an alarm at some specific vacuum. On the older units it was at 7 lbs vacuum. You can tee a vacuum gauge into the fuel line and see what vacuum the system is drawing. Testing should be done at max rpm, when the vacuum reaches it's maximum. Your readings will determine if the vacuum switch is bad or not-or if you have a fuel restriction. ezeke's comment about multiple filters is correct. Check the hose lines to the new separator filter and make sure the hoses didn't get bent or kinked when installed.