Fuel Question

fidalgoisland · Posted: Mon Jun 17, 2013 9:04 pm Post subject: Fuel Question

I know this topic has been discussed before but thought I would ask again for some fresh thoughts I had a motor problem this past weekend I am pretty sure was related to old gas. The engine would start but only run for about 30-60 seconds.

As a general rule, how long do you recommend leaving gas in the tanks before using and how much do additives help? I assume time of year is also a factor. Thanks.

Dennis

bridma · Posted: Tue Jun 18, 2013 12:29 am Post subject: Fuel Question

I am certainly not an expert, but I'll throw my 2 cents worth in. I have had a lot of boats, diesel and gas. But the principle is the same for any gas engine, lawn mower, weed wacker, etc.
If the engine has a small gas tank like a mower, I run the tank and the carb dry. For a bigger tank, such as a boat, at the end of the season, I fill the tank to full to reduce condensation, add an additive such as red Stabil, and that's it until the Spring. Winterizing the engine is another topic, I'm just talking about the gas. If I am not going to use the gas come Spring, then dump it. It's not worth trying to keep it for a year or two if it is not going to be used.
I was also told that when buying a new to you boat, dump the fuel, you do not know it's history, and start with fresh. How many of us actually do that is probably minimal.

Martin.

colobear · Posted: Tue Jun 18, 2013 12:50 am Post subject:

I don't think there is a definitive answer to your question. Like you (probably), my engines are carburated and I make a point of running the engines dry, draining the fuel bowls and treating the fuel in the tanks with Stabil grey (the marine stuff) at the end of a season or when I don't expect to use them for a couple of months. Some people argue that one should leave the tanks full..others that one should empty them. I have never worried about it but then my boat is on the water most of the year. I do use Sea Foam fuel additive pretty frequently. From what you say I would suspect your problem may well be in the carburetors. Some people have used almost a fifty fifty mix of sea foam and gas in the carb bowls to try to get rid of varnish. By the way, I think I have seen your boat at Condo 18, Skyline Marina

BrentB · Posted: Tue Jun 18, 2013 3:07 pm Post subject:

my theory and it is funny to me and not always to others is select fuel additives by the number of product testimonials Wink

starcrafttom · Posted: Tue Jun 18, 2013 3:52 pm Post subject:

Are your motors carbs or fuel injection? If carbs always run the motors dry and drain the carb , really easy to do, if you are not going to use the boat for a few weeks or longer.

Do you have a water separator before the engine? do you have one on the engine, many do and people dont know.

To tell you the truth I dont treat my gas at all. I also run my boat at least once a month. I try to use up as much gas as I can between fill ups. In other words if I pop out for a short fishing trip and only burn 10 gallons out of 100 I don't run to the gas station to fill up the missing ten. I general don't re fill unless one tank or the other is down to 1/4 or less. I believe, regardless of facts Wink

, that this keeps the tank cleaner and does not allow deposits and water to collect. I don't think that water and other deposits are the act of one fill up or another, but the accumulation of many tanks of fuel and the deposits that cone with them. I also don't believe that a large amount of fuel in a tank is going to go bad this year. Most if not all fuel /motor problems are caused by the small amounts of fuel in your lines and carbs. So why do they treat the gas in your tank? Well that's how it get's to you carb's don't it?? I would rather run a injector cleaner in my fuel to keep the injectors/carbs clean then worry about the fuel in the tank. but hey that's just me.

p.s. I also like to run a de-winterize or fog off spray thru the carbs once a year. It really helps keep your carbs working partrs clean and removes any carbon build up in the valves or pistons. Great for two or four strokes.

starcrafttom · Posted: Tue Jun 18, 2013 3:55 pm Post subject:

p.s. where you shrimping off jones on saturday?

fidalgoisland · Posted: Tue Jun 18, 2013 9:03 pm Post subject:

fidalgoisland · Posted: Tue Jun 18, 2013 9:22 pm Post subject:

fidalgoisland · Posted: Tue Jun 18, 2013 9:25 pm Post subject:

bridma · Posted: Tue Jun 18, 2013 10:52 pm Post subject: Fuel Question

Thanks Tom for your input. I learnt something new reading your post. The information and help on this site is amazing.

Martin.

billzbub · Posted: Wed Jun 19, 2013 3:44 am Post subject:

Here's my 2 cents from a total noob (this is my first boat):

May 2012: launched from Shilshole for 1st trip of the year. Warmed up both motors - the main motor, a 2006 Suzuki fuel-injected 90, and the kicker, a Suzuki 15, at the dock.

50 yards from the breakwater, the 90hp died, wouldn't restart. Fired up the kicker, and it promptly died, wouldn't restart.

Dropped the anchor, cursed the motors, and watched families play on the beach 20 yards away at Golden Gardens Park while we waited for BoatUS to show up and tow us back to the dock. (BTW, that BoatUS towing insurance coverage was one of the best investments I've ever made…)

That was how I learned that my boat had a fuel filter / water separator (told you I was a noob). It had a lot of water in it. I replaced it and assumed that my 20 gallons of fuel were also polluted with water. A Lake Union firm quoted me about $1000 to drain the fuel.

Instead, I called Todd McChesney at Blue Water Yachts on Lake Union. Blue Water had done the 200 hour service on the 90 hp. Todd explained how to drain the injectors and the internal fuel filters on the 90 and 15 to clear out the old, water-logged fuel.

It worked. With the use of Sta-Bil at each fill-up, and occasional draining of water from the fuel filter, we haven't had any more fuel problems (knock on wood).