I topped off all the jerry cans and inboard tank before heading out this weekend. I have a 12 gallon inboard for my old OMC saildrive. I poured enough oil in there for 4 gallons while pumping gas. Unfortunately I was only able to get about 3-3.5 gallons in there before the tank was full. We started up the inboard and it ran great... for about 60 seconds. Then it refused to start back up. Are these things really that sensitive to proper oil/gas ratio?
Did this seriously just clog my carb!?
- Thread starter Project_Mayhem
- Start date
I poured the oil in while pumping gas to help mix it. My outboard is running on gas from the same fuel dock. I have a separate tank for the outboard
Correction, WAS running off of the same fuel until the outboard bracket decided to break in half. Outboard went for a swim. Inboard refused to run. Had to get a tow up the river. It was a fun day
No, it wasn't that. More than likely just sediment. Better fuel filtration is becoming more important with the alcohol fuels as it seems to make hoses, tanks, everything, break down quicker. Installing a coarser filter, followed by a finer filter, as well as a water trap, as close as practical to the point of use, can make life better. Draining the fuel bowl if it is going to sit for more than a day or two makes a difference as well.
We used to mix oil and gas in our snowmobiles at the station...dump in the oil, and pump in the gas...I don’t think the engines are that sensitive to the fuel / oil ratio.
More likely sludge in the tank that got stirred up and clogged the filter.
Good luck.
Greg
More likely sludge in the tank that got stirred up and clogged the filter.
Good luck.
Greg
See if the carburetor has a drain plug in the float bowl. Take a Ziploc bag and use it to catch the fuel coming out after you open the plug. Use two Ziploc bags one inside the other in case the first one leaks. Then you can see if you have water or other gunk in the fuel. The fuel and water will be separated and gunk will be readily apparent. If the carb is anything other than pure fuel pull it apart and clean it. Then deal with the fuel in the lines and the tank. Also did you check for a spark at the plugs? Could be electrical but if it was running and the only thing that changed was filling it with fuel it is likely the fuel.
@jibes138 brings up a good point. I've had ignition problems do immediate shutdowns with no restart much more often than fuel. Usually, a fuel problem will give you a sputter, or pop, or something to indicate there's still fire (unless you've run completely out of fuel).
How long has it been since you last ran it? Has the other 8-9 gallons been sitting all winter?
Suggest you check the easiest thing first, carb drain, or spark. It could be a mere coincidence that it happened after fueling. If I understood correctly, you only put 3 gallons in a 12 gallon tank. Being off on the oil for 3 gallons out of 12 is insignificant. Unless that 3 gallons was mostly water, it's unlikely that it caused the sudden death you described.
Good luck and keep us posted.
How long has it been since you last ran it? Has the other 8-9 gallons been sitting all winter?
Suggest you check the easiest thing first, carb drain, or spark. It could be a mere coincidence that it happened after fueling. If I understood correctly, you only put 3 gallons in a 12 gallon tank. Being off on the oil for 3 gallons out of 12 is insignificant. Unless that 3 gallons was mostly water, it's unlikely that it caused the sudden death you described.
Good luck and keep us posted.
I went to go check on things last night. Found that the head was leaking so didnt get to check on the engine. This boat just keeps on giving...
There is a FRAM PS3808 filter installed which is labeled as a fuel/water separator. If this was a separator then logically there should be a drain for water? It looks just like an oil filter. Is there an element inside that collects or becomes saturated with water? Does it do any filtering of particulates?
This engine has always ran great. Sunday was the first time I had ever filled up at a fuel dock so this further supports the theory of stirring up sediment. Who knows if this tank has ever been cleaned
There is a FRAM PS3808 filter installed which is labeled as a fuel/water separator. If this was a separator then logically there should be a drain for water? It looks just like an oil filter. Is there an element inside that collects or becomes saturated with water? Does it do any filtering of particulates?
This engine has always ran great. Sunday was the first time I had ever filled up at a fuel dock so this further supports the theory of stirring up sediment. Who knows if this tank has ever been cleaned
Man, you're having a run of it! Doesn't have a drain, filters particulate and removes water (according to Fram). If you haven't changed it lately, it should be $10-12 so change it. There are no good descriptions of how the internals work, but one would assume exactly what you did, absorption of some type.
Marina gas could easily be the issue - depends on usage and maintenance.
Do you have a priming bulb in the system? Have you tried pumping fuel through the filter/separator. If it's clogged solid, it could produce the symptom you're seeing.
Oh yes, I'm almost seething with hatred towards this boat right now. Did I also mention that I was taking on water on Sunday during the tow and had to haul out? I'm starting to see why @cb32863 couldn't wait to get rid of his O'Day 25
The filter is new. It has maybe two hours of usage. The fuel dock appeared to be busy. DNR filled up there as well (although I'm sure their new fuel injected motors can handle bad gas better than mine)
The previous owner didnt like priming so he installed an electric fuel pump. There probably should be a pressure regulator but its running fine without one. Assuming the original fuel pump works correctly I was thinking about connecting my portable outboard tank as a test. Oil/Fuel ratio is correct in that tank as well
The filter is new. It has maybe two hours of usage. The fuel dock appeared to be busy. DNR filled up there as well (although I'm sure their new fuel injected motors can handle bad gas better than mine)
The previous owner didnt like priming so he installed an electric fuel pump. There probably should be a pressure regulator but its running fine without one. Assuming the original fuel pump works correctly I was thinking about connecting my portable outboard tank as a test. Oil/Fuel ratio is correct in that tank as well
Last edited:
A key item is that you started it and it ran great for 60 seconds. The fuel still in the filter and carburetor and fuel lines from the tank had the old gas mixture from before you filled the tank. Once the new gas made its' way to the carburetor the engine quit. Sure sounds like a bad (contaminated) gas scenario to me. If you have an electric fuel pump remove a hose and put the line in a quart mason jar and pump some gas in and look at it. I had about five gallons of bad fuel accumulated over the years. I went to the fire department to ask how to get rid of it. They told me to burn it ! Needless to say I looked for other disposal methods.
When you get on those downhill runs, you just have to ride it to the bottom and hope it comes quickly. Hang in there.
If it's easy to hook your outboard tank for testing, that would be a great way to tell you whether you're looking for an external fuel problem or not. Is that marina fuel in your portable tank?
@jibes138 is spot on. That's a good test for several issues.
I've had friends that got a load of bad gas before - from stations that got plenty of traffic. So, you're just going to have to test your way through a diagnosis. Now that you're hauled, maybe you can figure out which one of these "opportunities to excel" you want to tackle first.
I honestly cant remember if I topped the portable tank off after filling the jerry cans. I do have about a gallon of fuel that the outboard is happy with. Theres also another marina that advertises some advanced on-site fuel filtering for their fuel dock.
I totally agree that it ran on good gas left in the carb or lines before encountering bad fuel/ratio/sediment
I totally agree that it ran on good gas left in the carb or lines before encountering bad fuel/ratio/sediment
Put to bed the ratio argument. I’ve used 50-1 mix in my 4 stroke lawnmower to get rid of it and it ran fine. I always ran a rich oil mixture with no trouble. Any gunk in the carb will kill it. So will water. My lawnmower wouldn’t start this spring, tank fuel had completely separated into two phases, drained it, cleaned the carb fresh gas instant start.
I tried starting the little monster this weekend. Not even a sputter! The previous owner said he ran into the same issue at one point and had to have the carb rebuilt or cleaned. Now the question remains... Is it the gas or the carb? How do I get rid of twelve gallons of potentially bad fuel? Will leaving this "bad" gas in there till the end of the season gum up the carb?
Ok, it wouldn't start. Have you checked spark? Have you pumped fuel out of the tank, through the filter into a clear container to check fuel flow and potential contaminant (water)? We need some feedback to form some idea of what's happening. Right now, I'm still at air, fuel, or spark? I don't think I have any info to rule out or confirm any of the three are your issue. Sorry you're having such a bad run. Trust me, you're not alone.
Is it gas or carb? Right now, don't have a clue that it's either.
Will leaving bad gas in it till end of season clog the carb? If that's the problem, it depends on what "bad" means. If it's marine gas with water in it, and your separator didn't stop the water, the carb could be ruined by corrosion if you let it sit with water in the bowl.
How do you get rid of 12 gallons of bad fuel? Depends on why it's bad. If it's water, I'd pour the fuel off and use it in my lawnmower. Maybe put the last bit on anthills, or find somewhere that would take it. Last resort would be burning it in very small amounts at a time. But, I am from Alabama...
Is it gas or carb? Right now, don't have a clue that it's either.
Will leaving bad gas in it till end of season clog the carb? If that's the problem, it depends on what "bad" means. If it's marine gas with water in it, and your separator didn't stop the water, the carb could be ruined by corrosion if you let it sit with water in the bowl.
How do you get rid of 12 gallons of bad fuel? Depends on why it's bad. If it's water, I'd pour the fuel off and use it in my lawnmower. Maybe put the last bit on anthills, or find somewhere that would take it. Last resort would be burning it in very small amounts at a time. But, I am from Alabama...
Last edited:
Have a 2-1/2 hp four cycle outboard on my inflatable. I also have a lawnmower and a snowblower. After having to replace the carburetors on both the outboard and the snowblower one year I switched to "Real Gas" available in 5 gallon cans at a Sonoco station nearby. That gas has no alcohol. It costs about $75 for five gallons and lasts me about three years. Never use additives, never drain carburetors, and never had a problem after the switch.
Corn does not belong in internal combustion engines. I do not care how much the corn farmers bribed our congressmen. Can I get an Amen?
Corn does not belong in internal combustion engines. I do not care how much the corn farmers bribed our congressmen. Can I get an Amen?