Boat related question

KnotRight

KnotRight

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I have a 1975 Mako 17 Angler with a 2015 E-tec on the back. It sat up all 2020 with a full tank of gas (24 gallons). Took it out last weekend and burned about a 1/2 of a tank and started having problems with the motor maintaining a steady RPM. Check the fuel water separator and there was some water in there.
The questions are: Do I fill the tank back up (non-ethanol gas) and let the separator do its job? Find some additive to add to the 12 gallons of gas and let the separator do its job? Or drain the 12 gallons that I have in the tank. I DO NOT care about wasting the 12 gallons, but it is a PIA to get the gas out and then what do you do with it after you have collected it?
 
I wouldn't that run gas through a $15k outboard. No matter what you do will "fix" the gas.

What has happened is called phase separation. Nothing you can do will remedy that.

26 years in gasoline industry, I don't care if it's non-ethanol or not there is a bit of ethanol in the gas, unless the tanker was steamed and dried.
 
Id trash the old gas. And fill with new gas adding marine grade stabil in the appropriate dose. Then continue to stabil at every fill. You may be able to remove the feed line at the motor and let it pump itself out.

Fresh filters as well.

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I'd pump that old gas out, grab a bottle of heat add and swash it around, by driving the boat on the trailer and dump it out too. Fresh fuel.
 
GoWolfpack said:
Are you saying your gas is 18 months old?

Do not run that in your boat.
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(About a month or so earlier it ran great. Same gas that has been in there for a year or so)

I ran the boat for 20 minutes on the wash rack twice. Then got into it and ran WOT out to the sound (7 to 8) miles, then back to Thunderbolt WOT about 10 miles. Idle through Thunderbolt and noticed that it was not running at 100%.. The ran to downtown Savannah maybe 12-13 miles at WOT. When I got to River street it kept bouncing between 4000 RPM down to 3000 and then back up.

I would think that the water problem would show up on the run to the sound.
 
KnotRight said:
(About a month or so earlier it ran great. Same gas that has been in there for a year or so)

I ran the boat for 20 minutes on the wash rack twice. Then got into it and ran WOT out to the sound (7 to 8) miles, then back to Thunderbolt WOT about 10 miles. Idle through Thunderbolt and noticed that it was not running at 100%.. The ran to downtown Savannah maybe 12-13 miles at WOT. When I got to River street it kept bouncing between 4000 RPM down to 3000 and then back up.

I would think that the water problem would show up on the run to the sound.
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It's probably not so much the water as the fuel degradation and the engine trying to compensate for the trashy fuel
 
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Make sure your filter is 10 micron. Racor's are recommended. I personally use the racors that have the clear bowl and peacock on the bottom to drain any water should it get in vs the oil filter style that you can't see in. The generic filters most big box stores carry are only 20 micron (bigger mesh hole) and will let water through. It has to be 10 micron.

When was the last time you replaced your fuel lines and bulb? If its been a few years and there's a chance of ethanol fuel in them, replace, its cheap. Your lines may be collapsing at higher rpms. I've had that happen on the first OEM lines the skiff had. Use only a BRP brand bulb (rest are crap) and good fuel line, not attwood/sierra/bigbox brands.

Personally, with that new engine, I'd drain all that fuel and overhaul fuel system (new tank pickup, fittings, line, and blub) if it wasn't done with the new motor. Also there is probably a small filter under the cowl that will need replacing. You also need to figure out where that water came from. Most likely the tank vent. Is there something deflecting water into the vent? Is a rubber oring on the top of the gas cap gone and rain water gets in? Is the vent line cracked allowing condensation/rain in?

To drain the tank, go get a cheap 12v fuel pump from advance auto and 10' of cheap auto fuel line (it'll be single use). It's worth the cost and saves a lot of time. I have a 42 gallon tank and about 5 years ago we overhauled the fuel system one afternoon. I drained the gas and with a stiff piece of copper wire, used clean rags to wipe out the inside. We replaced the fuel pickup in the tank which degrades over time and ran all new ethanol resistant fuel hose, new brass fittings, and new BRP bulb.

I burn only pure gas in both the 115 Yami and the 2 smoke 50hp Rude jon. The jon has dedicated gas cans for only the boat when I refill to avoid contamination from ethanol. Paying $0.60 more per gallon is nothing compared to $1400 injector job on the 115yami.
 
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2ndAmendmentSteve said:
I'd pump that old gas out, grab a bottle of heat add and swash it around, by driving the boat on the trailer and dump it out too. Fresh fuel.
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If I'm not mistaken, Heet is basically just ethanol.
 
tod0987 said:
Make sure your filter is 10 micron. Racor's are recommended. I personally use the racors that have the clear bowl and peacock on the bottom to drain any water should it get in vs the oil filter style that you can't see in.
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tod0987, that is the filter that I use. It was changed about a 2 weeks ago and the filter on the motor was also replaced. Today, I had to take the whole filter off because I could not get a glass under the nipple. I bought a hose to hook on the nipple and run it out of the drain hole in the transom to a glass on the ground.

i only use ethanol free gas.
 
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KnotRight said:
tod0987, that is the filter that I use. It was changed about a 2 weeks ago and the filter on the motor was also replaced. Today, I had to take the whole filter off because I could not get a glass under the nipple. I bought a hose to hook on the nipple and run it out of the drain hole in the transom to a glass on the ground.

i only use ethanol free gas.
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As I stated above. It may say non ethanol. But it still has a bit In it.
 
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