Fuel tank sediment

[Bill O'Donovan]

I keep reading about the need to get the sediment out of the bottom of the fuel tank, but I'll be damned if I can figure out how to access it. On my 1995 Hunter 29.5, the tank is behind the aft wall and shows no access for draining. I looked at the fuel bowl setup running parallel to the shaft, but I'm puzzled how to handle that. I just want to get any water/residue out while the boat is laid up. Any advice? Or steer me to another portal on HOW that may have this subject archived. Thanks.

 

[Ed Schenck]

A different opinion.

A seemingly knowledgeable Yanmar mechanic told me not to worry about the tank. He did recommend removing the pickup screen so that it could not clog. But he said that a Racor filter will trap anything that could come from the tank and it is easily cleaned.If the screen on the pickup tube does clog you can clear it. Simply pull the hose at the Racor and blow back through it. But not having it there to clog is preferable because now you have to bleed the fuel system.Despite this opinion you will find lots written in the archives on the subject. Many have cut cleanout ports in the tops of their fuel tanks.

 

[Ralph Johnstone]

Fuel Tank Inspection

I think Ed provided the best answer with an access port drilled into the top of the tank.This is what I am presently doing on our 1999 H310. Machined a 316 SS plate into a 2" dia. disk which is 0.5 in. thick. Drilled and tapped a 0.25 in. NPT hole in the middle and then 0.125 in. holes near the edge so that it looks like a small flange. Drilled a 0.375 in. hole in the top of the polyethylene tank and then screwed the flange on it with NO. 2 Permatex as a sealant. Finally inserted a 0.125 in. pipe plug and the job is finished.When required, I now remove the pipe plug and use my vacuum oil pump (used for changing the oil thru the dip stick)to pump out the bottom of the fuel tank.Regards,s/v Island Hunter

 

[Doug]

Larger racor

You may want to put a second (assuming you have a smaller unit already) racor in line to the first. We used the 500 series and it has a huge filter and water separater with clear plastic view at bottom. You may fuss with cleaning your tank only to find sediment problems again in a season or two. But getting this out of the fuel prior to getting to your Yanmar primary fuel filter is really the important thing. This will also get out the water and you can view the amount collected so you can empty as needed. Keeping your tank topped off in colder months will greatly reduce the amount of condensation and thus water accumulation in your tank.Doug

 

[Bill Verburgt]

What I do each Spring is to stick a tube down the hole vacated through the removalof the fuel gauge. A piece of cake. The tube I use is the plastic tube sold by plumbing stores that goes to the toilet tank. This I hook up to my oil retraction pump and I pump out about a quart of fuel off the bottom.It works!Good Luck,Bill

 

[Bob Belvin]

Racor input screen clogging

I have a '91 33.5 and had a case where the engine would not keep running for more than 5 minutes. Tried changing the Racor filter element but no help. Turns out the Racor filter has an input screen that was clogged up. I had to remove the element and input hose to clean it. Rough water stirred up the trash in the fuel tank and caused the problem. I now need to clean the bottom of the tank before I venture into heavy water again.BB on WindDance