OK brain trust.... motor question

tod osier

tod osier

Well-known member
Supporter
I have a Nissan 3.5 hp that I use as a kicker on my Snowgoose - motor has an internal tank. I keep it stored tied in the boat and it does not get used much at all (hopefully never). I put new gas in every year and start it and run it for a while and then close the fuel shutoff and run the carb out of gas. The tank cap has a seal at top and stopcock shutoff at bottom so it can be closed for storage. Problem is that I've split 2 tanks over the years, apparently from the pressure - it is common for these little internal tanks to split I understand.


I have a new tank on order and I'll put it in, but the question is how to store the tank from now on to maximize function when I need it and to keep the tank from splitting. The first tank I split I was storing with the tank pleasantly full (with a nice air space for expansion). Second tank I was storing with the tank completely full thinking liquids don't expand much with temperature (but knowing that they are incompressible when they do expand).


So, thoughts? Store the tank empty and vented and fuel when needed? I could see the gas and oil in the tank getting pretty skanky vented though. Stored cleaned out and slightly vented would be an option I suppose, but the tank is extremely hard to empty completely. With our current gas situation (10% ethanol) I'm hesitant to vent the tank with fuel in it for any length of time. I don't want to store empty and sealed since that is more likely to split the tank. I'm thinking of buying the premixed stabilized cans of gas if it last better than pump E10 and this is my only WC motor and it only takes .37 gallons, so premixing for it is almost silly. Cleaned out and vented seems my best option, but I'm open to ideas. If I use the motor I'm having a bad day, so I want the best chance of it running.
 
Last edited:
Tod,
I'm not familiar with that particular fuel system. My first thought;
(A) store the tank empty and I mean empty, void of fumes as well.
(B) even if empty, the tank may split with pressure change if sealed up, therefore locate a second cap that you can drill a couple holes in for venting purposes. Put a zip tie thru the holes to clearly mark it as the vented cap. Screw the vented cap onto the tank to keep the tank free of debris and such. Attach the good cap to the motor so you have it when you need it.
(c) store your fuel supply in an appropriate container. Refreshing said fuel supply as needed.
 
Tod,
I'm not familiar with that particular fuel system. My first thought;
(A) store the tank empty and I mean empty, void of fumes as well.
(B) even if empty, the tank may split with pressure change if sealed up, therefore locate a second cap that you can drill a couple holes in for venting purposes. Put a zip tie thru the holes to clearly mark it as the vented cap. Screw the vented cap onto the tank to keep the tank free of debris and such. Attach the good cap to the motor so you have it when you need it.
(c) store your fuel supply in an appropriate container. Refreshing said fuel supply as needed.
Click to expand...

Motor cap has vent and actually a foam filter inside vent - screw type with rubber seal (seals very well, obviously). Otherwise I think your approach is pretty much what I settled on.

Thanks for your thoughts.
 
Perhaps this is a stupid response, as I am by no means a motor expert. But why not store it nearly full, allowing a little air space to deal with any expansion, and seal the vents to prevent water intrusion?

FWIW, I've stored mine both full (maybe 90%) and empty, vents closed, without problems. Mine's a Tohatsu 2 stroke. There is always Stabil and a slightly richer than 50:1 fuel/oil mix in the tank, storage or during the season.

Now, if you can tell me how to get the dang thing to a low idle, I'm all ears.
 
Perhaps this is a stupid response, as I am by no means a motor expert. But why not store it nearly full, allowing a little air space to deal with any expansion, and seal the vents to prevent water intrusion?

FWIW, I've stored mine both full (maybe 90%) and empty, vents closed, without problems. Mine's a Tohatsu 2 stroke. There is always Stabil and a slightly richer than 50:1 fuel/oil mix in the tank, storage or during the season.

Now, if you can tell me how to get the dang thing to a low idle, I'm all ears.
Click to expand...

That is how I used to keep mine when I split the first tank, mostly full with a little air space. Maybe that tank was just bad. I will say the two tanks split in completely different places.

Can't help with the idle, mine has been good.
 
Last edited:
Tod,
This is probably a long shot. I am going to assume this motor does not have a fuel pump and that the carb is gravity fed. If so, what I am going to suggest will NOT work. (how's that for a positive contribution?)
If this motor has a fuel pump, can you eliminate the internal tank and rig up quick connect fittings to connect to your main tank when and if needed? Even if your motor does not presently have a fuel pump, some motors can be fitted with an optional fuel pump just so they can be run from a remote tank.
 
Tod,
This is probably a long shot. I am going to assume this motor does not have a fuel pump and that the carb is gravity fed. If so, what I am going to suggest will NOT work. (how's that for a positive contribution?)
If this motor has a fuel pump, can you eliminate the internal tank and rig up quick connect fittings to connect to your main tank when and if needed? Even if your motor does not presently have a fuel pump, some motors can be fitted with an optional fuel pump just so they can be run from a remote tank.
Click to expand...

Yes, but I'd rather the tank internal. I think I'll just run the tank dry, clean it out and store it empty with separate premix with the vent cracked.
 
Just a thought: I use a marine gas stabilizer in every small engine I own...outboards, gas lawn tractor, chainsaws, weedeaters, generator. They: a. run better in season and b. I don't drain tanks; rather, I fill them, and they run just fine after months of inactivity. Example: my generator gets started maybe three times/year, and its starts and runs well on the first or second pull. My 15hp 4-stroke Merc outboard sits all winter and spring. Starts right up first time out in summer.
Gary
 
Just a thought: I use a marine gas stabilizer in every small engine I own...outboards, gas lawn tractor, chainsaws, weedeaters, generator. They: a. run better in season and b. I don't drain tanks; rather, I fill them, and they run just fine after months of inactivity. Example: my generator gets started maybe three times/year, and its starts and runs well on the first or second pull. My 15hp 4-stroke Merc outboard sits all winter and spring. Starts right up first time out in summer.
Gary
Click to expand...

Thanks for the suggestion, I'm sure that will do the trick.
 
Todd

I like to keep things simple. I don't have any experience with the small kicker, so my thoughts maybe totally worthless. But I keep 3 gallons of fresh fuel as backup in a plastic gas can in my Bankes. I regularly (every few weeks) pour that gas into my main tank. Why not keep your kicker empty, lid vented, a small plastic gas can (they make 1 or 1.5 gallon) of straight gas that is stabilized and a can of oil out of the way. That way you can keep fresh gas, oil, and the motor all stowed until you need them. You aren't mounting the motor in a hurry so time shouldn't be a big concern while you mix up the fresh tank.

I really don't like the idea of fuel in a tank stored horizontally, long term storage of fuel or running the motor dry to empty the fuel lines and carb (I'll defer to Tom S or another experienced small motor mechanic on this issue, but running an engine to starvation just seems like a bad idea).
 
Todd, I would go with the tank empty and a can of premix handy. Have not heard of so much trouble with tank splitting. Just curious, what is your main motor? On my fishing boat I have both motors OMC without a tank on the 3 hp. so I can just switch the fuel line. Probably not much help but that works for me.
 
Todd, I would go with the tank empty and a can of premix handy. Have not heard of so much trouble with tank splitting. Just curious, what is your main motor? On my fishing boat I have both motors OMC without a tank on the 3 hp. so I can just switch the fuel line. Probably not much help but that works for me.
Click to expand...

Thanks Tom. Main is a Yamaha F40, so not mixed fuel. I like not depending on the same fuel supply, since the only problems I've had with my Yamaha were fuel related (water) before I put a water separator filter in.
 
I hate the new gas. I have more problems with 2 stroke equipment now regardless of additives.
I use real gas with stabil. It lasts so much longer.
This site helped me to find a place that sells it:
http://pure-gas.org

LOL.
I do not work in any oil related or mexican food industry.
 
Todd

I like to keep things simple. I don't have any experience with the small kicker, so my thoughts maybe totally worthless. But I keep 3 gallons of fresh fuel as backup in a plastic gas can in my Bankes. I regularly (every few weeks) pour that gas into my main tank. Why not keep your kicker empty, lid vented, a small plastic gas can (they make 1 or 1.5 gallon) of straight gas that is stabilized and a can of oil out of the way. That way you can keep fresh gas, oil, and the motor all stowed until you need them. You aren't mounting the motor in a hurry so time shouldn't be a big concern while you mix up the fresh tank.

I really don't like the idea of fuel in a tank stored horizontally, long term storage of fuel or running the motor dry to empty the fuel lines and carb (I'll defer to Tom S or another experienced small motor mechanic on this issue, but running an engine to starvation just seems like a bad idea).
Click to expand...

No, I hear you on the running it out of gas, but I'm going to keep doing it. The motor always has started beautifully when stored that way and that is my priority - not longevity of the motor. I don't run it - I had to work hard to get in the hours to get it broke in, and I try to actually run it on the water every year (rather than in the driveway).
 
Like others, I run marine stabile, but I've also tried the premix, ethanol free, fuels in one of my chainsaws. The stuff really burns great. Thinking your empty tank and one of these fuel cells would be worth the try. And hopefully your just trying it in warm weather and never have to see if this really works.
 
I hate the new gas. I have more problems with 2 stroke equipment now regardless of additives.
I use real gas with stabil. It lasts so much longer.
This site helped me to find a place that sells it:
http://pure-gas.org

LOL.
I do not work in any oil related or mexican food industry.
Click to expand...

We have no real gas here. I will bring it back when I travel to make premix for kicker, string trimmer, chainsaws, etc.. and for my other motors.

I use stabil or seafoam in all my gas, have for 10 years.
 
Like others, I run marine stabile, but I've also tried the premix, ethanol free, fuels in one of my chainsaws. The stuff really burns great. Thinking your empty tank and one of these fuel cells would be worth the try. And hopefully your just trying it in warm weather and never have to see if this really works.
Click to expand...

I think I'll buy the stuff in the can to try, would be very convenient. I make premix for this motor annually and since I don't run any other TC-W3, I end up putting it in the car when I make new anyway.
 
Brad, As far as running a motor til it quits, no worries. There is plenty of residual oil in the fuel to lubricate during a run dry. I wouldn't probably run it dry under a load of at high R.P.M. just because. The real misconception about "running dry" is that it doesn't REALLY run dry, there is always just enough fuel left in the float bowl to dry out and turn to trouble. Some of the older carb motors had a drain in the bottom of the float bowl but that has kinda gone away. This is a very interesting topic both professionally and personally.
Also for any of you looking for alcohol free fuel, contact a old car club or association. Here in Minn. the Minnesota Street Rod Assoc. has compiled a list of stations that have "good" gas.
 
Last edited:
For the most part here in the South we can run our engines year round, if not most of us use fogging oil for long term storage.

Running engines out of gas for storage can allow internal parts to condensate with temperature changes during storage and create rust or corrosion. Keeping them fueled up may allow evaporation and shellacking or crud to build up. Marine stabilizer is great stuff to prevent problems while fueled up during the offseason.........or take a few minutes to properly fog the cylinders, carb, etc. You will save yourself some headache after Spring thaw, gaskets and seals stay lubed and this prevents deterioration or drying out. You can fog any engine and it'll be ready come Spring.
 
For the most part here in the South we can run our engines year round, if not most of us use fogging oil for long term storage.

Running engines out of gas for storage can allow internal parts to condensate with temperature changes during storage and create rust or corrosion. Keeping them fueled up may allow evaporation and shellacking or crud to build up. Marine stabilizer is great stuff to prevent problems while fueled up during the offseason.........or take a few minutes to properly fog the cylinders, carb, etc. You will save yourself some headache after Spring thaw, gaskets and seals stay lubed and this prevents deterioration or drying out. You can fog any engine and it'll be ready come Spring.
Click to expand...

Thanks for the suggestion, I'm sure that will do the trick.
 
You must log in or register to reply here.
Back
Top