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Port engine running rough

G

gastite101

Member
I have had my boat in dry storage for the winter since Oct1st 2009. I kept the fuel tanks at ¾ full and added some dry gas before winter. I also added antifreeze to all the raw water side so it does not freeze.

04/08/2009 I had the boat but into the water for a weekend cruise. The boat started great and ran great. We went about 63 miles total. On our way home we were doing 2900 rpm’s and about 15-16 knots for about 2 hours none stop, the boat ran great until
We got in-front of the entrance were I had to throttle back. Soon as I did that the port engine started to run very very rough. There was smell of gas but not in the engine room or cabin, it smelled like it was coming from the exhaust like the engine was not firing correctly and not burning the gas. When it first happen I did not see any black or white smoke coming from the exhaust and we had to run it for 1/2 hour down the river to the docks and still have no smoke, we did not hear and bangs or anything like that. The engine ran but I could not get it over 1100 rpm's and when I had to slow down to get into the dock it went to 400-500 rpm's but did not stall. I am at ¼ tank of fuel when we arived now so I am going to assume I might have water in the gas line and some in the tank. :confused:

Can I get your input Captains?

I plan to replace distributor cap, rotor, points, spark plugs, plug wires and change the main fuel filter and the fuel filter in the carb to see if that helps along with some dry gas and a good fill up of fuel. Before we went I did top off the feul tanks with fresh gas, about 1/4 tank worth.

Thank you
 
Do you have water seperators on your fuel system? Change out your filters as well and carry spares on board. Sounds like water in the tank. Good luck on the search.
 
You should have added an alcohol fuel system treatment (like marine Sta-Bil or Star Tron) before putting her away (running it through the engines first). That dry gas simply added more water absorbing stuff to the tank. It should ONLY be used in a closed fuel system, like modern cars and trucks. Since yours is vented, the tank sucked in moisture all winter and the alcohol absorbed it, freeing the gas to take in even more water.

The result is a layer of non-burnable "gook" formed by the ethanol in gasahol and water--the infamous third liquid. The below photo shows what it looks like, and it will NOT burn as you have discovered. Frankly, you're lucky to have gotten that far with it in your tanks!

The cure is to let the boat sit overnight, then suck out the bottom 1/4 of the fuel with a hose that goes to the bottom of the tanks. In doing this, you need to walk on eggshells to prevent mixing that stuff with your gas.

Jeff
 
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Rather than try to suck out the water & ethanol, you might want to try to find a company that specializes in filtering your current fuel and tank. You also won't waste any of the fuel. I had it done on my previous boat that had chronic ethanol & water issues. I drained my entire tanks and still had problems until a company called "Fuel Solutions" (NY based) ran it through their filter system and back into my tanks - I think it was about $400 for both tanks. I still had to change the fuel filter and carb filter about 2 more times right after they were done (they said it was most likely because there was still ethanol in the fuel lines), but there were never any other problems after that.

When you pull your carb filters, throw them in a plastic bag and let them dry, if you see a powdery tan substance - that's ethanol.

I'd never waste time and money again on trying to empty my tanks when there is a service available that can cure it completely.
 
I am just wondering ...you mention fuel tankS....do you have muliple tanks or a single tank that feeds both engines?
 
I'm assuming you're asking gastite if he has two tanks and not me? My old boat had two tanks and each fed an engine, but I did have the ability to run both engines off one tank (valve system) which did help me isolate the problem to one tank and probably what you're going to recommend that gastite does ---that's a very good idea! Once he changes the filters on the port side, shut off that port tank and try running both engines from the starboard tank.
 
I have two tanks.
One 100 gal Star
One 100 gal Port

I spoke to a mech in Seattle and he said for me to get the stuff that fastjeff said (Sta-Bil or Star Tron) and poor 1 whole bottle in each tank. Replace all the filters on both tanks and fill up the boat with fresh gas and add some gas oil to the fuel tanks, it will help the carb pins and all the little parts in the carb. The mech also said I need to see where the 2nd stage carb is at because if the 2nd stage (4th) is stuck open I would get the same type of problem as if it was water in the tank, adding to much fuel. He thinks I might have some water in the tank and feels trying Sta-Bil or Star Tron will help and cant hurt any.
 
If you have access to the tanks and can open the sending unit mount, IT MIGHT be prudent to use a dip tube to see if the bottom of the tank is "crudded up". Like those big straws they use for testing wines. Jeff's suggestion is a good one and if you have enough junk in there, no amount of fuel additive will provide an easy fix. It just depends on whether or not you plan on a 100% effort or some other level to get out of this jam..my 2 cents
 
The additives won't hurt but the gas oil (2 cycle oil?) isn't necessary. If the secondaries are hung open, the engine won't idle down (rpm-wise).

If you have that "crud" in your tank, you really need to remove it; there isn't anything you can add to the fuel to break it down.

You can also plumb in an outboard tank, temporarily, to see if the issue is with the fuel in the main tank. Just be careful as any fuel (fume) leak can be dangerous.
 
I took some time before the gas guy and oiled the carb and cleaned all levers and springs and used a carb lubricant and then started the port engine. The engine ran smooth and good. The guy next door said that if there is any water it would be in the back due to the boat being tilted a-little so it should run ok. I am sure he is correct.

Well today I got 95% of the gas out. Thank god I only had a ¼ tank of fuel.
The guy that did it said I have about 1-2 gallons in each tank.
He suggested that I replace all filters and get some good gas stabilizer and one can for each tank of hi octane booster on the first fill up. He could not tell how much water was in the tank but feels that taking the gas out and starting from empty is the best thing to due. I hope he is correct. My next trip will be Seattle Opening day of boating and it would suck if the boat started to act up again.

Thank you fellow boaters for your input.

Jim in Seattle
 
Hi team.
The boat is out of the water. I cleaned the carb and put fresh gas after draining the old stuff.
While the boat is out of the water the engine on the Port side runs great and the other engine is also doing well. Do you all think I might have a diffrent responds when in the water?

The place is good about getting the boat in that water but it sucks because if there is a problem and the port engine is still not running correctly I still have to move the boat to the otherside to have lifted out of the water.

I guest the questions is if you started your boat on land and it ran well would you feel confident that it will run well when put into the water? :confused:
 
I will agree with Jeff. You are probably good unless the angle of the lift sloshed all of the gook away from the pickup tube in the fuel tank. But if you think you did drain it all, you should be fine.
 
That is interesting knuckle47 and fastjeff. I found no gook in the fuel when we were sucking out the gas. The guy that did it had 2 clear 50 gal tanks so you can see everything that went into the tanks. He used a different tank per fuel tank. The guy was nice and even stayed for a few hours to see if there was any water at the bottom of what we sucked out and nothing. Some of the guys at the Marina think it was a combination of three things.
Bad gas. Replaced all the fuel with fresh fuel.
Junk that got into the carb. I fixed it when I cleaned the carb and fixed the gas
Choke. fixed when I cleaned my carb


Thank you all for your input. Please have a fun safe boating season and be well.
 
The gas can breakdown (some say turn sour) and not ignite very well long before it starts to give any visual clues.

I have an old weedwhacker that will not run on "old" fuel (> 60 days old). In the spring and fall, when the temp swings all around and the fuel blend is changing, sometimes 4 weeks is the max....been that way since the ethanol notices started showing up on the pumps.
 
Good! You should be all set now.

Jeff

PS: If you let the gas sit dead still for a "while" the junk settles enough to be seen.
 
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