Loss of engine power in rough seas

[brhodes]

Had an experience this weekend starting back from Saturna Island to White Rock, BC. About 5 miles out in shipping lane, with a third of a tank and rough water, and the fuel gauge swinging from zero to half - the engine started to lose power. After reducing revs it ran for a while, but worsened as did the weather. A couple of miles further it started to stall on idle. I shut down and ran the auxiliary kicker the six miles into Point Roberts marina. Filled up the tank and set out into even rougher seas, and the motor ran great all the way home.

I assume this was an airlock issue due to a partially empty tank, but should this occur with a third of a tank of fuel? According to the book, i could have primed the injectors manually. Didn't do this at the time, but would this have solved the problem? By the way, the motor manual shows clearly the bleeder valve on top of the fuel filter, but not the prime bulb for the 40 horse. Is it the red corrugated rubber bulb on the stern side of the injector array?

Bruce
Red Current EC-21

 

[dloop]

Scary. I'm glad you made it safely Bruce. This is a good reminder for the value of an auxiliary kicker. I don't always take mine with me (lazy). I need to get better about doing that.

I hope you resolve the issue, but don't do testing by yourself in seas like those.

dave

 

[bbrh842]

You may have had less fuel in your tank than the guage indicated.
On my R-25, when the fuel guage shows 1/2, the tank is only 1/3 full.
So I presume if my fuel guage was showing 1/3, the tank would be realy REALLY low.
In rough conditions this could cause the fuel to slosh completely away from the fuel pickup in the tank ???

 

[dloop]

By the way, the motor manual shows clearly the bleeder valve on top of the fuel filter, but not the prime bulb for the 40 horse. Is it the red corrugated rubber bulb on the stern side of the injector array?

Hi Bruce,

Are you referring to the stop bulb in this picture?

http://www.flickr.com/photos/dloop/4767989973/


Also, you mention 40HP, but you have a 30HP, correct?

dave

 

[brhodes]

Thanks for the picture. The stop solenoid is definitely NOT the prime bulb that i thought it was! The picture does show the manual pump valve elsewhere; i shall investigate.

I do actually have the only factory installed 40 Yanmar that i am aware of. I think it was an experiment by the factory, and it gets about 1 - 2 knots more than the 30 with comparable fuel economy due to lower revs. I am very happy with the engine - and i am not sure why it is not offered as an option. But, i still doesn't turn this boat into a speed demon!

 

[Ram]

It sounds very much like the symptoms of a clogged fuel filter.

We experienced a number last summer after getting a tank of "dirty fuel". It seems that the pounding of the boat exacerbates the problem, so it tends to happen in the worst conditions. Got really good at changing the primary filter in a hurry.

Certainly worth considering this possibility.

 

[Paradox]

This happened to me this February with 1/3 tank indicated on the fuel gauge on my 21EC; rolling side to side, the fuel gauge was hitting empty on the rolls, and the engine stalled.
I have added a primary filter coming out of the fuel tank, and try to keep the tank at least 1/2 full. There are no baffles n these tanks, and air can be sucked into the fuel line if the fuel pick up is exposed to air on the rolling of the boat.

 

[Portugeezer]

Hi Bruce & Debbie,

I was very aware of the winds on July 4 and that you were likely sailing home. I worried. It was nice to see the Red Current under the tarp next day. I wonder if there is anywhere else on earth where there are two red R21s on the same block? They say imitation is the best form of flattery. Hope you guys take it as such.

John

 

[Toodles]

I got low fuel pressure while in 6 foot seas with about 1/3 of a tank remaining (using the fuel calculator for the 130hp Cummins) Being a shallow tank I believe that the fuel does not feed well and needs to be topped off for rough seas.

 

[thataway]

Probably picking up air into the fuel lline. A "Solution" is adding a "day tank"--smaller tank which is narrow and deep, with a pump from the primary diesel tank which will keep the fuel pick up fully engaged. If you get any air in the day tank is is just vented out. The symptoms could be a fuel filter, but filling the tank would not have solved the probelms.

 

[Levitation]

Last summer I got into violent seas in the Detour Passage - electronic buoy in the passage measured them as 7 footers on a 4 second interval, these are vertical walls of water... The boat was pitched up and down hard enough to eject the sleeping bags, sheets, pillows, etc. from the vee berth into the aisle and then fling them back and forth the length of the aisle with each cycle like they were in a wash machine...
The fuel tank <luckily> was nearly full, so the Cummins hummed along like a sewing machine at 1250 rpm and 4 knots and at no time did I feel we were in the slightest danger...
<Pasta the dog, to this day does not agree with me. The Admiral just rolls her eyes when it is brought up and walks away.>
I am slightly embarrassed that I got us into that, yet I have the satisfaction now of knowing what the R25 is capable of doing...

It was mere chance that the fuel tank was full for us.. So learning from the experience of Bruce, I now have an operating pearl - when entering rough water have a full tank...
In hindsight it is predictable... The tank is a flat pan... So 1/3 full is very little depth of fuel... As the boat rolls/pitches the fluid is going to rush back and forth making foam... So, even if it does not uncover the pickup, there will be foam pumped to the engine...