1981 Hunter 30 Fuel Tank Clogged

[mbirk81]

I found my Yanmar 15 will only run about 15 minutes until she shuts down. After replacing all filters I took the fuel line off the tank and put directly into a new fuel can. She ran fine. I presume my tank is clogged with algae. Should I remove my fuel tank and have it cleaned or is there a cleaner that will work in place? My Hunter has a 12 gal metal tank which may be lifted out through the starboard lazzarette. Any suggestions will be appreciated.

 

[jssailem]

Removing and cleaning the tank is a definite option. The problem may also be in the pickup tube sitting in the tank or in the fuel lines from the tank to the Primary filter. When you changed the filter (assuming this is a primary and not the one on the engine - identified as the secondary) what was the condition of the filter material. Clean of filled with small black stuff looks like pepper. Any gummy stuff in the fuel line openings or the ports on the filter? Any water in the filter housing?
Can you see into the tank? Can you see any particulates in the fuel? Is the fuel color dark/black with floating stuff? Can you see a sludge on the sides/bottom of the tank?
Sludge is a remove and clean signal. No sludge but water or particles floating may be solved by fuel polishing.
No primary filter system? Getting on may help stop the junk from getting to the engine filter.

 

[lee oakley]

I had a problem with mine that was about the same. All I did was completely drain the tank and put some stabil cleaner and got fuel from a place that all they sell is ciesal to make sure it was top of the lineand it was cured

 

[Capt jgw]

Check for a filter screen on the end of the pick up tube. If there's one there remove it. Those are one of the most stupid things ever put on a boat. You want that gunk to be caught in the primary filter, not plugging up the tube where you can't get to it.
They're also might be a filter screen in your lift pump, but that's after the filter so not as likely plugged.

 

[mbirk81]

JSsailem, Thanks for the reply. The filters were pretty clean. I saw one black speck in the engine filter. For my test to the new fuel can I put hose on the racor filter to the fuel can. I have not tried to remove the pick up tube yet. I cannot see into the tank.
Lee, Thanks for the note and ideas.
Capt JGW, I will attempt to pull the pick up tube out on my next day off.

Has anyone removed the fuel tank on the Hunter 30'??

 

[jssailem]

If you have a fuel filter blockage you will see it full of black particles and perhaps even a jelly like goo. If you put a vacuum gauge on the engine side of the pump you will see a high vacuum level with the engine trying to draw fuel through a clogged filter.
Based on your not seeing stuff clogging the filter I would start looking between the filter and the tank. Following a clogged filter I changed it and for a short time the engine ran then it stopped again. We flushed the pickup tube and it cleaned up the issue and the engine ran again.
Do you have any openings on the top of the tank? I am able to look into the tank by removing the fuel level sending unit. It leaves a 2.5 inch diameter access to the tank.
This is an opening I plan to use to filter the fuel in my tank and using a 1" diameter pick-up tube and return the fuel back into the tanks through the same hole with a smaller line to spray the fuel into the tank and stir up any crud while I cycle the fuel through filters. Expectation is I may not get everything but to reduce the level of the crud.

 

[HMT2]

I had a similar problem on my Yanmar 2gm it ended being a clogged vent. Check that first especially if your filters are clean other than getting to it it is an easy fix.

 

[mbirk81]

HMT2,
I heard that too and checked the vent, it was clear.
Still waiting for a day off to pull the pick up tube.
Thanks,
Mark

 

[mbirk81]

I pulled my fuel tank out, not as hard as it looked, found the tube is attached to the tank. There are small specs of black substance. Anyone have suggestions on the right cleaner to break this up and clean out my tank?