Is this from bad gas??

[scipper77]

Mercruiser MCM185 (a rare 3.8 liter 229cid, not the omc one, 1985)

Went out today with a half tank. Boat was performing normally. I went out to a spot on the lake trolled and came back, maybe 5-6 miles round trip included some near WOT runs. No issues with the boat whatsoever at this point.

I came back in to the bay I launched from because my fuel was getting low. I had gone from 1/2 tank to 1/4 tank at this point. I decided to go across the bay and cast a few lures before the sun set and then it happened.

While cruising at 1/2 throttle the motor started to hesitate. I immediately turned around and headed for the launch. On my way back the boat hesitated and stalled out. The first time I tried to restart the motor cranked slowly like the battery was weak (brand new battery verified to be fully charged after I got home). The boat restarted and I cruised in at 1/4 throttle until 5 minutes later the boat hesitated off and on and then stalled again. I restarted (started right up this time) and finished the trip at maximum "no wake" speed (1/16'th throttle).

The gas in my tank is from last season. I have never dealt with fuel issues before but my feeling is that there is likely water in my fuel. The hard start was a near hydro-lock experience?? I am hoping I can siphon the remaining gas out and fill er up with fresh stuff and be on my way.

Does this sound like a bad gas situation or should I look further in to this before I try to take the boat out again??

Please guys, any help,opinions, or personal experiences would really be appreciated.

Note: every time the boat stalled the throttle was steady.

 

[scipper77]

Re: Is this from bad gas??

Bump...

Anyone know the part number for the fuel filter?

 

[reddogg]

Re: Is this from bad gas??

If the gas is from last season, it's definatley a suspect. I'd siphon some out and take a look/smell it and see what shape it's in. If it's gone bad (bad color, odor, allot of crap in it) I'd pump and dump it and replace fuel filters. Hopefully no crap got into your carb.

red

 

[scipper77]

Re: Is this from bad gas??

Here is my plan. I probably have 3-4 gallons left in the tank. I am going to siphon at least 2 gallons out (size of my free gas can). I'll do this bow up with the hose in the rear corner of the tank. It is my hope to get and sediment or water off of the bottom of the tank by doing this. Next, I'll swap the fuel filter and gas up with fresh fuel. The gallon or so that is left I would hope is now diluted enough to run without any mishaps.

If I can I will try to get all of the old gas out but I do not have appropriate containers to store all of the gas. I am hoping that getting the junk out of the bottom of the tank is the more important issue here as the boat ran perfectly until I got to the bottom of the tank.

The only fuel system maintenance that I know is overdue is the fuel filter. If the carb is blocked I will pay a pro to do a rebuild. I kind of like the idea of having the carb redone anyways for my piece of mind.

Is this plan worth trying, or do I need someone to set me straight as to the appropriate way to address this????

 

[90stingray]

Re: Is this from bad gas??

If the fuel filter is overdue then by all means CHANGE IT! Sounds like a clogged filter to me. But since the fuel tank is so low you can go ahead and take a sample.

 

[John_S]

Re: Is this from bad gas??

If you are talking about the water seperating filter, dump the contents in a glass jar and check for water or other contamination. Should check what you siphon out of the tank, as well.

PS: Buy a 5-6gal gas tank and siphon out everything you can. Get all the crap out you can. You don't want to dilute with new, and hope it is ok.

 

[scipper77]

Re: Is this from bad gas??

I do not have a water separator. I will try to get all of the fuel out. I have no idea what I am going to do with the old gas but that is another thread.

What is the best way to siphon the gas? Fill tube? Access port in floor? (i'm not sure what is under that cover.)

 

[HT32BSX115]

Re: Is this from bad gas??

I do not have a water separator. I will try to get all of the fuel out. I have no idea what I am going to do with the old gas but that is another thread.

What is the best way to siphon the gas? Fill tube? Access port in floor? (i'm not sure what is under that cover.)

Howdy,


First of all, 3 or 4 gallons of last years gas can just be left in there. fill it with fresh gasoline. If you have a filter, you can replace it with another one. Is it a "spin-on"?
If not, you should replace with a spin on type that will be water separating......

EVERY YEAR I run my (44 gal) tank down to about 1/4 to 1/2 and fill it in Spring with "fresh" gas. It has never been a problem.

If you want to have a look at what's in your tank though, remove that inspection plate.

Your gage sender should be under it. before removing it, get a (gage) gasket kit so you can replace the gasket under the tank sender.

Once the sender is out, you can get yourself a long length of clear vinyl tubing (long enough to use it to fill a tank sitting on the ground from inside the boat)

Start a siphon and have someone hold the other end in the can on the ground while you use the your end to "vacuum" the bottom of the tank from inside the boat.

If you connect a short piece of PVC tubing on your end of the hose you can move it around to get any debris or water from the bottom of the tank (tip the bow up a little if the gage sender-hole is towards the back to make everything go towards the hole)

DO THIS OUTSIDE!! No smoking and have a fire extinguisher ready!!


I seriously doubt your gas is bad enough to be a problem after only 6-8 months.....


Cheers,


Rick




I

 

[Sea Rider]

Re: Is this from bad gas??

If it's ethanol mixed and not having stabilized gas remains when boat came to a wintwer stop, throw away all tank gas leftovers, change filters, fill with new gas, should perform fine.

Happy Boating

 

[HT32BSX115]

Re: Is this from bad gas??

If it's ethanol mixed and not having stabilized gas remains when boat came to a wintwer stop, throw away all tank gas leftovers, change filters, fill with new gas, should perform fine.

Happy Boating

I'll have to disagree with you .......I park my boat every SEP in my dry garage with 1/4-1/2 tank of E10 gasoline and fill it up every JUNE and I never use "stabilizer"............and it performs fine............

Went out today with a half tank. Boat was performing normally. I went out to a spot on the lake trolled and came back, maybe 5-6 miles round trip included some near WOT runs. No issues with the boat whatsoever at this point.

I don't think you can just assume that "old" 10 is automatically the culprit after his above description........

 

[Sea Rider]

Re: Is this from bad gas??

I'll have to disagree with you .......I park my boat every SEP in my dry garage with 1/4-1/2 tank of E10 gasoline and fill it up every JUNE and I never use "stabilizer"............and it performs fine...........

Don't know much about Merc inboards, but on 2/4 t outboards you cannot keep gas remains that long period of time and expect to run fine, at the most max 3 weeks use without staibizer, if maintaining for long periods any boat and tank out of dry environments, tank will surely pick moisture inside. Ethanol is a natural moisture picker...Anyway checkig gas remains will be the fastest way to troubleshoot. Good Luck!!

Happy Boating

 

[John_S]

Re: Is this from bad gas??

If it is just end of season, last year gas, it is not causing the problem. You either have water or other contamination, or a different problem. But, you have to look at it in a glass to see. If you find anything, my recommendation is to get it all out the best you can. If you haven't run your tank that low in years, it could have been there for quite awhile.

 

[scipper77]

Re: Is this from bad gas??

I appreciate the spirited discussion. After thinking about it there is a little more to the story. Last year I had no tow vehicle for most of the season. I only got the boat out 2 or 3 times. I bet I only burned through 1/2 tank last season. So maybe the gas this year is 1/2 from last year and 1/2 from the year before. In any event I am going to pull out all of the gas that I can and replace the fuel filter. Let's just hope my issues are as simple as that.

Also, is it a bad idea to use blue rtv to reseal the sending unit on the tank? I'm sure somewhere local will have the gasket but if they don't I would consider it as long as it is a safe practice.

<EDIT> Looked it up, silicone based products are no good for fuel use <EDIT>.

 

[scipper77]

Re: Is this from bad gas??

progress. I pulled the fuel sender and put a hose in there. Started the siphon the "old fashioned" way. I could not get the siphon started so I called my neighbor and it turned out he has a pump. Went back to the boat and was horrified to find that the siphon did start after all and the can was full with at least a quart of gas on the driveway. I switched cans and tried not to think about the fact that I was one spark away from loosing my boat and possibly my house.

I filled the two 2.5 gallon cans and a little bit more to boot. The fuel sender has a cork float which I'd say after 27 years does not float as well as it once did. This means that the whole time I have owned the boat I have had more fuel than I thought in the tank (good to know).

While I did not get all of the gas out I did get most of it out. The gas was dark but the tank looked to be free of debris and water. The fuel filter I ordered comes in on Wednesday. Lets hope with the new filter and fresh gas all is well.

P.S. I soaked up the gas in the driveway with paper towels and those paper towels are in my fire pit airing out.