Diesel fuel question

[sailnski]

I am about to start my engine up for the first time this year having done some extended work on my boat. I have about a half tank of fuel from last season and didn't put biocide in the tank at that time. Do I need to pump the diesel out of the tank and refill?

Thanks.

Catalina 30 TRBS, M25

 

[Benny17441]

I don't think that during the winter months your boat was subjected to excessive heat and condensation cycles so your fuel might likely be OK. Any bacterial debris will have mostly sank to the bottom of the tank. You may consider replacing the fuel filters after a good shakedown outing. If you want to polish the fuel and clean the tank I would not argue about the benefits but to just pump out and replace fuel I don't think it will do much. Watch and drain the water separator for the first few runs.

 

[sailnski]

Thanks, Benny, I appreciate our reply.

 

[DougM]

I’m beginning to think people are paranoid with regard to living and dying organisms in their fuel tanks. Twice in the 17 years I have owned my boat, it had to remain in storage outdoors over two consecutive winters. After spring commissioning, and new batteries, we launched and on engine restart, it fired up on the first turn. Some of the fuel in the tank each time had to be more than two years old and overly diluted with Stabil. Most seasons I would be surprised if I used 5 gallons of diesel.

 

[jssailem]

SailnSki... Fire it up and give her a run about the bay. Take along a couple fuel filters. If you have two filters in the system it is handy to have a vacuum gauge in the system to provide feed back as to clogging of a filter. The gauge sits between the first filter and the fuel pump. When the gauge begins to show a high vacuum reading, then the first filter in your system is becoming clogged. You can validate this by changing the filter and then inspecting the filter medium.

This is what a dirty clogged filter looks like when your fuel is 3-5 years old and the boat has been sitting in a marina.


Symptom experienced. The engine RPMs suddenly surged a couple of times. The signs of fuel starvation and the pump sucking the last fuel from the system. Then the engine stopped.

Change the filter, bleed the fuel lines, start the engine, your back in business.

 

[sail sfbay]

Agree with the posts above.....I will add that I started up my sailboat and truck diesel engines after sitting without a fuel stabilizer/biocide after 3 years while living overseas.

 

[dLj]

The only time I've drained a diesel is one time after it had been sitting for over 15 years.

dj

 

[jssailem]

I've drained a diesel is one time

Once you've drained a diesel the smell sticks with you a life time.

 

[sailnski]

Thanks for all of the suggestions. Maybe this was a case of too much reading, as I am new to larger sailboats and diesel engines. I have plenty of secondary fuel filters from the previous owner and will purchase a couple that go in the primary filter.

Cheers.

 

[Monterey385]

Also bear in mind that with the fuel return the best polishing is actually running the engines while having the boat in a bit of waves (and then changing the filters)