yanmar requires bleeding after rough weather

woodster · Sep 2, 2014

djekels said:
I have noticed that after every storm thats includes rough water heights ranging from 3 to 5 ft and the boat bouncing left, right, up and down I needed to bleed the engine as she refuses to start.

does anyone know how i can prevent this from happening?

two things come to mind here

1 make sure your fuel and filters are clean and your dip tube in the tank is not some what blocked

2 make sure you have adequate fuel level in your tank and not loosing prime bouncing around out there

kito · Sep 2, 2014

That's what is was thinking Woodster. Fuel level low and sucking air when the fuel is sloshing around.

rardiH36 · Sep 2, 2014

My experience is the same as Woodster's #2 observation.

If I allow my fuel level to go to ~25% (= 7.5 gallons of 30 gallon tank), my Yanmar 2QM20 will suck air during any sort of chop. Once that happens, bleeding is required before the engine will start again. Not a dangerous issue if I have enough wind to sail to smooth spot of water near my marina so as not to repeat.

After my second incident like this, I now will not let my fuel level go below about 33%.

But I do have the advantage of doing only day sailing. So I never have to "go the distance" in respect of my 30 gallon limit ... as I expect cruising sailors will often need to do.

Maine Sail · Sep 2, 2014

djekels said:
I have noticed that after every storm thats includes rough water heights ranging from 3 to 5 ft and the boat bouncing left, right, up and down I needed to bleed the engine as she refuses to start.

does anyone know how i can prevent this from happening?

Keep the tank more full and when it comes time to replace the tank add some baffles.

Steve Dion · Sep 2, 2014

Isn't the pickup tube normally aluminum? It should not be moving around?

It was common for that era to have screens on the tube which could be plugging up. Pull it out and see.

Maine Sail · Sep 2, 2014

djekels said:
baffles in the tank please explain?

If your tank does not have baffles and the tank is also not full, or close to it, the fuel can slosh from one side to the other and the pick up tube sucks in air. Baffles slow the sloshing.

Take a Tupperware container half full and slosh it around, like your boat moves, and you will see how one area can have no water while another one still does.

MrBill_FLL · Sep 3, 2014

I do NOT recommend foam in the tank, since it degrades over time, but you could use this. (if you replace the foam every ~2 years)

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=0HX7GQGQ6ZSC27BPRC1R

OTOH, I only have experience with Gas/E10 fuel and foam. it clogs all filters when it breaks down...

Maine Sail · Sep 3, 2014

MrBill_FLL said:
I do NOT recommend foam in the tank, since it degrades over time, but you could use this. (if you replace the foam every ~2 years)

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=0HX7GQGQ6ZSC27BPRC1R

OTOH, I only have experience with Gas/E10 fuel and foam. it clogs all filters when it breaks down...

?????? Baffels are usually welded plastic or aluminum dividers depending upon which tank material you have...

MrBill_FLL · Sep 3, 2014

if he doesn't have any baffles, I would think he'd have to cut a large opening to install some. OTOH, foam prevents sloshing of fuel in race cars, (and could do same in boats). but the foam breaks down over time.

-or, foam is only good for a short term fix, when you had to travel long distances by engine. *or*, just keep fuel jugs aboard to keep it full, all the time.

-what about a small 'day tank' ?