Fuel Tanks

[awalker]

Found significant contamination in fuel system which caused involuntary engine shutdown and subsequent tow back to home port. It seems I have a lot of junk in my tanks. What action should I take to remedy this problem. My boat is a 1998 Gulfstrem 232 with a 2 stroke Yamaha 250. Any advice would be appreciated.
Thanks for helping a newcomer!

 

[seasick]

What are your tanks made of. Poly or aluminum?
Was the boat sitting for a while before the last run?
Did you just fill up?
This will help determine if you just got a bad load of fuel or if you have a more severe issue.
Regardless, you will probably need to have the tanks drained and all filters replaced. If fuel injected,Your injectors may be contaminated but you won't know that until later. If carbureatted, you will most likely need to get the carbs cleaned

If the tank is aluminum, sometimes ethanol gas will disolve the old varnishes that built up. Once cleaned, the tank will be OK but engine oarts may be clogged.
If the tank is poly, its probably bad fuel.
Could also be phase separation. A sample from the tank left to sit for a while will show if the fuel separated. If so, pretty much the same actions needed.

 

[Grog]

Unless you can find someone to polish the fuel, carry some extra 10micron water separating fuel filters or pay some $ to have it pumped out and disposed. If you get some Racor fuel filters with the plastic bowl, you can see what's setteling out.

I'm pretty sure all Grady tanks are Aluminum.

 

[Offshore24]

If the tanks are original they are aluminum.

Not sure about where you live, but up here we switched over to ethanol fuels last year. Going to see lots of plugged filters as a result. Keep changing filters and draining the water trap, if you have one. Add marine stabilizer to fuel for a while, or at every fillup. I've drainaed my own tank before but it's a PIA. Can't say how to clean the junk out though, short of pulling the tank and sloshing some solvent around, redraining and repeating. Another PIA.

 

[awalker]

Thanks for replying to my question. I purchased the boat at the end of last season from an 83 year old gentleman who rarely used it. The boat was delivered with full fuel and 147 hours total time. It has never been re-engined and the times were verified by Boats Inc. invoices. The tanks are aluminum and I think your suggestions of installing a water separator is wise advice. I'll need some help to drain the fuel tanks and clean out the old fuel but I'm fairly handy and can change filters and install the separator.
Thanks again to everyone for lending your experience and knowledge.

Walker

 

[gradyfish22]

Depending on the price, if you can find a serive that will polish the fuel that might be better since your talking about 100gal or so of fuel. Polishing it is not cheap, but in the end you keep the fuel and can use it, draining the tank will mean you loose the fuel and then need to replace it. Neither is cheap and needs to be left to professionals. I would highly advise adding startron enzyme treatement, it will asborb some water if present and pass through the engine safely, and will save you a filter or two over the course of the season if you truely have issues. If you have lots of particales, that is a different story and you really need the tank cleaned out and drained to properly do it. My advice would be add Racor 2micron filters, that way no junk reaches the engines. Carry spare filters so you can safely change it on the water and get in and avoid the tow feee and trouble. The clear bowls are the way to go to determine if your problem is just water, or particles as well anmd is easy to monitor. Every boat should have an external fuel water seperator nowadays, it is a cheap insurance policy for your engine.

 

[seasick]

I'm pretty sure all Grady tanks are Aluminum.

My tank is poly, factory original.

 

[seasick]

You need to get the fuel pumped out at a minimum. Don't waste your money on new filters until you do so. All you will do is clog them up.
After the gas is out don't fill up, Drain and check the filter under the cowl also. Use the bulb to see if fuel flows into the engine filter, if it does, you don't need to change the water separator yet. Your carbs may be gummed up also and will cleaning but see if you can start the motor first before disassembling the carbs.
After you are pretty sure that things are back to normal, change the water separator and add more fuel. Don't fill up for a while, it is better to keep adding a little more than you use in a trip for a while to keep the fuel fresh. Every time you add more fuel you will dilute the existing contaminates if present and burn them off.

 

[richie rich]

what everyone has said is definitely true, but there's a bit more as well. Had the same problem. Over the years the older MTBE gas left a bit if a varnish in the gas tank walls. When everyone switched to E10, the alcohol dissolved the varnish, a little at a time and plugged the carbs. I have 10 micron Racors and changed them 3 times a season and still got orange particulate in the engines little pre-filter and in the carbs...rebuilt the carbs, ran well for 2 tank fulls and then started giving problems.......installed brand new carbs, went 2 to 3 tankfuls or 500+ gallons and the engines started sputtering again. changed filters like they were going out of style....added Startron etc.....ended up pulling the tanks out and changing them as they were geting pitted anyway.....

Just draining may not do it........if you keep finding orange particles in your engines pre-filters or carb bowls...you may need to pull the tanks to either really properly clean them or just replace them. Those orange particles are like gels which squeeze throught the 10 micron Racors...it make continue to be a long-term problem...