Engine power reduction.

[Clydo]

I thought - since keep fuel tank topped off - should get some fresh fuel not knowing how
long old stuff in tank. Ran tank down to quarter full. During annual get ready had change
eng fuel filter in February and Racor fuel/water sep at same time. Was bit bouncy and
started eng, dropped sails and headed back to marina. Had eng about 2500 rpm when
slowed right down. Pushed up to full rpm ran ok back to about 2500. Couple minutes
later same thing happened. Got back to marina twenty minutes later. Changed eng
fuel filter, drained Racor little bit. Checked for water and there was some. Drained
little more no water present. Next day ran eng out and about for almost hour turning
tight circles trying to get some bounce and no problem. Someone suggested I drain fuel
tank and clean it out. Have topped off tank and everything seems ok. Any thoughts?
Pulling tank and cleaning on 13 year old boat with 429 hours bit of chore. I get fuel
from busy truck stop and use West Marine fuel filter when refilling.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

 

[JK_Boston_Catalina310]

Was the tank full when you were doing donuts to get the wake?

 

[KZW]

Two thoughts.
1. The fuel will gravity feed to the engine as long as the tank is more than 1/2 full. Is your fuel pump working? On my boat, you can crack the fuel bleed line at the block, and have a friend turn the ignition key past the "on" position to turn on the glow plugs. The fuel pump should come on at the same time and you will see fuel bubbling out of the bleed fitting.

2. Is the Racor is in the lowest part of the line on your boat? Mine is located under the rear bunk, aft of the engine raw cooling water sea cock. Water at the bottom of the tank will be picked up and end up in the Racor. If you did have water, and needed to drain it, perhaps you were getting water to the engine?

 

[Clydo]

Two thoughts.
1. The fuel will gravity feed to the engine as long as the tank is more than 1/2 full. Is your fuel pump working? On my boat, you can crack the fuel bleed line at the block, and have a friend turn the ignition key past the "on" position to turn on the glow plugs. The fuel pump should come on at the same time and you will see fuel bubbling out of the bleed fitting.

2. Is the Racor is in the lowest part of the line on your boat? Mine is located under the rear bunk, aft of the engine raw cooling water sea cock. Water at the bottom of the tank will be picked up and end up in the Racor. If you did have water, and needed to drain it, perhaps you were getting water to the engine?

All good points. Have bleed eng in past using method you suggested. Had no problems with air in lines since replaced
filters in February this year and bleed air out at that time. My Racor is located same position as yours. Drained out small
amount first time and found water. Drained small amount next time no water. You may be right that some water
got past Raor into eng? My first thought some crud from fuel tank caused problem since this my first experience with
Racor. Thanks for your response.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

 

[jssailem]

Clyde, have some experience with fuel issues. When you changed your filters were they clean or dirty? ( look of coffee grounds on filter element)
When you tightened the lines after bleeding the air from the lines could there be air still leaking in? Friend installed a vacumm gauge which showed air leak from pinched o ring that leaked air. Air caused loss of power.
Sometimes dirt or goo in tank can block the fuel pickup tube. Wave action stirs fuel and dirt which then blocks tube. When you look in tank does it look dirty. ,
Could you have water leaking in around fuel caps, have you checkec the o ring on the filler cap recently?

Just a few ideas on the usual suspects.

 

[Donnybrook]

Clyde, ANY water in the Racor means you have water in the tank. The fuel pickup tube does not go to the bottom of the tank, therefore, draining the Racor will not get all the water out. Crud grows in the water. Eventually, the bottom of the tank will corrode and give you a fuel leak. As part of my routine preventative maintenance, I suck the bottom of the tank at least every 2 years. More often if I find any water. Using off road dyed fuel makes it easier to spot water. I use a plastic pump that is made to pump oil out of a quart oil container. I buy a long section of automotive brake line from auto parts store. I cut off one end and remove the fittings. The uncut end fits perfectly into the pump. Remove the pickup tube from the tank and aim the brake line to the deepest end of the tank. Water will settle to the bottom of the tank. Pump into a clear glass container and let it set for about 10 minutes. Any water will settle out and look like milk. Black crud will usually settle on top of the water. Properly dispose of the mix until you get clear fuel which can be poured back into the tank fill. This procedure will save big headaches later.

 

[JamesG161]

I had the same problem.
Not the fuel, but throttle control "creep" (as it was called by several SBO posters).

Changed eng
fuel filter, drained Racor little bit. Checked for water and there was some.

But...
Not all Racor's are not built the same.
On mine, Racor 500FG, I can see if there is water without changing the filter element.
______
As you described it, why would trace water slow the RPM? Fuel flow restriction at high RPM, maybe. You didn't state what was the maximum RPM recommended for your engine. Mine is 3000, so 2500 rpm sounds a bit high to me. Did you have the same problem at lower RPM's?
______
Here is my Racor shown in my Post #6
http://forums.sailboatowners.com/index.php?threads/fuel-line-maintenance.180546/
And my Racor analysis on my post #31
______
If you had no engine "chugging" then perhaps your replacement fuel filter was 2 micron and not 10 or 30 micron. It takes a LOT of water (dispersed with diesel) to "disturb" a diesel engine's performance. Cigarette smoke particles are ≈10 micron. In other words, you can't blow smoke through a 2 - 10 micron filter cartridge.
As others have suggest, the old cartridge appearance will give you a lot of info and the KEY to fuel tank status.
____
I wouldn't jump to the conclusion of "water in fuel" yet.

Was bit bouncy

How big is your fuel tank and what was the tank level when you observed the RPM effect?
Jim...

PS: A guy named Diesel, developed an engine to run on "Crap" fuel.

 

[Clydo]

I thought - since keep fuel tank topped off - should get some fresh fuel not knowing how
long old stuff in tank. Ran tank down to quarter full. During annual get ready had change
eng fuel filter in February and Racor fuel/water sep at same time. Was bit bouncy and
started eng, dropped sails and headed back to marina. Had eng about 2500 rpm when
slowed right down. Pushed up to full rpm ran ok back to about 2500. Couple minutes
later same thing happened. Got back to marina twenty minutes later. Changed eng
fuel filter, drained Racor little bit. Checked for water and there was some. Drained
little more no water present. Next day ran eng out and about for almost hour turning
tight circles trying to get some bounce and no problem. Someone suggested I drain fuel
tank and clean it out. Have topped off tank and everything seems ok. Any thoughts?
Pulling tank and cleaning on 13 year old boat with 429 hours bit of chore. I get fuel
from busy truck stop and use West Marine fuel filter when refilling.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

I thought - since keep fuel tank topped off - should get some fresh fuel not knowing how
long old stuff in tank. Ran tank down to quarter full. During annual get ready had change
eng fuel filter in February and Racor fuel/water sep at same time. Was bit bouncy and
started eng, dropped sails and headed back to marina. Had eng about 2500 rpm when
slowed right down. Pushed up to full rpm ran ok back to about 2500. Couple minutes
later same thing happened. Got back to marina twenty minutes later. Changed eng
fuel filter, drained Racor little bit. Checked for water and there was some. Drained
little more no water present. Next day ran eng out and about for almost hour turning
tight circles trying to get some bounce and no problem. Someone suggested I drain fuel
tank and clean it out. Have topped off tank and everything seems ok. Any thoughts?
Pulling tank and cleaning on 13 year old boat with 429 hours bit of chore. I get fuel
from busy truck stop and use West Marine fuel filter when refilling.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

 

[Clydo]

I thought - since keep fuel tank topped off - should get some fresh fuel not knowing how
long old stuff in tank. Ran tank down to quarter full. During annual get ready had change
eng fuel filter in February and Racor fuel/water sep at same time. Was bit bouncy and
started eng, dropped sails and headed back to marina. Had eng about 2500 rpm when
slowed right down. Pushed up to full rpm ran ok back to about 2500. Couple minutes
later same thing happened. Got back to marina twenty minutes later. Changed eng
fuel filter, drained Racor little bit. Checked for water and there was some. Drained
little more no water present. Next day ran eng out and about for almost hour turning
tight circles trying to get some bounce and no problem. Someone suggested I drain fuel
tank and clean it out. Have topped off tank and everything seems ok. Any thoughts?
Pulling tank and cleaning on 13 year old boat with 429 hours bit of chore. I get fuel
from busy truck stop and use West Marine fuel filter when refilling.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

Was the tank full when you were doing donuts to get the wake?

 

[Clydo]

Tank 3/4 full when doing donuts.


Clyde Thorington
C310 #245
ILEAN TOO
San Jose, CA

 

[Clydo]

Clyde, have some experience with fuel issues. When you changed your filters were they clean or dirty? ( look of coffee grounds on filter element)
When you tightened the lines after bleeding the air from the lines could there be air still leaking in? Friend installed a vacumm gauge which showed air leak from pinched o ring that leaked air. Air caused loss of power.
Sometimes dirt or goo in tank can block the fuel pickup tube. Wave action stirs fuel and dirt which then blocks tube. When you look in tank does it look dirty. ,
Could you have water leaking in around fuel caps, have you checkec the o ring on the filler cap recently?

Just a few ideas on the usual suspects.

I should have cut filter open to see what it looked like but didn't. Just installed new. Eng started ran fine after bleeding. No
apparent air leaks anywhere in February when first changed filter. Check o ring in filler cap when refuel. Looks good.
Wave action may have stired up gunk which caused initial brief power loss (twice).

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

 

[Clydo]

Clyde, ANY water in the Racor means you have water in the tank. The fuel pickup tube does not go to the bottom of the tank, therefore, draining the Racor will not get all the water out. Crud grows in the water. Eventually, the bottom of the tank will corrode and give you a fuel leak. As part of my routine preventative maintenance, I suck the bottom of the tank at least every 2 years. More often if I find any water. Using off road dyed fuel makes it easier to spot water. I use a plastic pump that is made to pump oil out of a quart oil container. I buy a long section of automotive brake line from auto parts store. I cut off one end and remove the fittings. The uncut end fits perfectly into the pump. Remove the pickup tube from the tank and aim the brake line to the deepest end of the tank. Water will settle to the bottom of the tank. Pump into a clear glass container and let it set for about 10 minutes. Any water will settle out and look like milk. Black crud will usually settle on top of the water. Properly dispose of the mix until you get clear fuel which can be poured back into the tank fill. This procedure will save big headaches later.

All good stuff. Will have my son in law get back and check/drain tank. Thanks for all the help.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose,CA

 

[JK_Boston_Catalina310]

Tank 3/4 full when doing donuts.


Clyde Thorington
C310 #245
ILEAN TOO
San Jose, CA

I would really check the fuel lift pump. I suspect that might be part of the issue.

 

[Clydo]

I would really check the fuel lift pump. I suspect that might be part of the issue.

Very good point. At marina guy put meter on it and said was receiving 13. something volts. Think that was number. Would be something to check
at time of future immediate power loss but question comes to mind when first happened applied full power and
rpms picked up to close to 3100 indicated. After couple minutes reduced rpms to around 2500 when few minutes
later repeated problem and recovery. After second recovery back to around 2400 rpms back to marina about
twenty minutes away. Wonder if lift pump failed all fuel flow would stop so no recovery to higher rpms?

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

 

[JK_Boston_Catalina310]

Very good point. At marina guy put meter on it and said was receiving 13. something volts. Think that was number. Would be something to check
at time of future immediate power loss but question comes to mind when first happened applied full power and
rpms picked up to close to 3100 indicated. After couple minutes reduced rpms to around 2500 when few minutes
later repeated problem and recovery. After second recovery back to around 2400 rpms back to marina about
twenty minutes away. Wonder if lift pump failed all fuel flow would stop so no recovery to higher rpms?

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

Mine acted exactly like this. We were crossing Pillsbury Sound between STJ and STT. It gets a little washing machine like in there. When the tank started sloshing around it would cut out and almost stall or stall and then restart. The tank cab gravity feed until it gets below half to a quarter tank, then it needs the lift pump or the engine stalls.

 

[jssailem]

Clyde,
No one asked how your fuel tank/s are arranged. Do you have one tank that you are lifting fuel out of the bilge? or do you have a day tank that you use and a main tank?
If you have a solo tank with long fuel to engine lines and multiple filters in the path, then sloshing around should not have caused any air gap in fuel that would have triggered a RPM problem. If you have a small day tank these are often located near the engine and thus nearer the fuel line and it may have caused the type of event you identified.
A second thought could the movement of the boat caused a slippage or a movement of the fuel control? I know I have bumped my fuel control and changed the throttle level by accident. Hearing the engine change sound always causes a lump in the throat and a OK what is happening moment.

 

[JK_Boston_Catalina310]

Clyde,
No one asked how your fuel tank/s are arranged. Do you have one tank that you are lifting fuel out of the bilge? or do you have a day tank that you use and a main tank?[quote/]

He posted in the Catalina 310 forum. Most of us who responded own 310s as well. But the arrangement is a single tank with baffles installed low at the stern of the boat. The tank can gravity feed when full down to below half. At that point the 12 volt fuel lift pump is needed.

 

[Clydo]

Clyde,
No one asked how your fuel tank/s are arranged. Do you have one tank that you are lifting fuel out of the bilge? or do you have a day tank that you use and a main tank?
If you have a solo tank with long fuel to engine lines and multiple filters in the path, then sloshing around should not have caused any air gap in fuel that would have triggered a RPM problem. If you have a small day tank these are often located near the engine and thus nearer the fuel line and it may have caused the type of event you identified.
A second thought could the movement of the boat caused a slippage or a movement of the fuel control? I know I have bumped my fuel control and changed the throttle level by accident. Hearing the engine change sound always causes a lump in the throat and a OK what is happening moment.

One 27 gal fuel tank. Others have said gravity feed until half or quarter full. I have one fuel/water separator and
one eng mounted filter. Believe fuel/water (Racor) sep is 10 micron and eng 2 micron. Throttle lever under control
at all times. Don't think air problem but possible crud in tank and or fuel lift pump problem. Thanks for your thoughts.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA

 

[Clydo]

Mine acted exactly like this. We were crossing Pillsbury Sound between STJ and STT. It gets a little washing machine like in there. When the tank started sloshing around it would cut out and almost stall or stall and then restart. The tank cab gravity feed until it gets below half to a quarter tank, then it needs the lift pump or the engine stalls.

Did you solve problem by (1) cleaning tank (2) replace fuel filter (3) replace lift pump or all of the above?
Thanks for your comments.

Clyde Thorington
C310 #245
ILEAN TOO
San Jose, CA

 

[iSailor]

I would really check the fuel lift pump. I suspect that might be part of the issue.

I second this. I was experiencing the same issues with mine and replaced the fuel pump (after countless filter changes and exploring other possible causes).....zero issues since replacing the pump 2 years ago. Oh, and I got the pump from NAPA.