Four stroke short term storage

[Terrier]

I have a Tohatsu 3.5 four stroke. Was wondering how many of you turn off the fuel **** and run the fuel out of your four stroke carb when you are done using the engine for the day, or week, or month? How many of you do not run the fuel out and leave it as is for a week or a month or so? I could not find any information on this in the owner's manual. I am not talking about winterizing.
The reason I ask it that this is my first four stroke and on my 2 stroke, I always run the fuel out of the carb before I take the boat out of the water. On the other hand, on my 4 stroke lawnmower, I don't. Don't want to have carb issues.
Thanks.

 

[pvanv]

Re: Four stroke short term storage

I always recommend turning off the fuel **** when stopping for more than a few minutes. That way, if the engine is tilted, the only fuel that can spill is the small amount in the carb bowl. I would also close the tank vent. Don't overtighten the vent, just seat it lightly, or it will be difficult to open later.

As for running the carb dry, I usually don't bother, unless it's going to be at least several days until it's started again, or if the motor will be tilted up. If the fuel is left in there for weeks on end, it will spoil, and that can gunk up the jets and passages. Overnight is not a big deal. Mine often sits full from Sunday night until Thursday afternoon with no problems. Keep in mind that you can't run the bowl completely empty; The motor will stop from fuel starvation when the bowl is down about half way, but it does help.

The big thing is to only use fresh fuel, and to religiously run a good stabilizer, such as K100-MG in the gas, especially with today's E-10 gas.

 

[TOHATSU GURU]

Re: Four stroke short term storage

The theory that we have used for the last 60 years(applies to 2 and 4-strokes) is that you should always run the fuel out of the engine at the end of the day. As Paul said, it doesn't make a difference in the short term. But, people have a habit of NOT using the engine when they intend to. Next day plans turn into next week plans, next week plans turn into next month, etc.

 

[Terrier]

Re: Four stroke short term storage

Thank you both for your input.

 

[Terrier]

Re: Four stroke short term storage

Just thought of something else. Is the risk of problems greater with a 2 stroke since there is oil in the gas? In other words, does the straight gasoline make it less prone to gumming up? Also, Tohastsu Guru, is the carb bowl bleed screw on the 4 stroke Tohatsu 3.5 located on the starboard side of the bowl?

 

[Wee Hooker]

Re: Four stroke short term storage

"But, people have a habit of NOT using the engine when they intend to. Next day plans turn into next week plans, next week plans turn into next month, etc."

You know me Elvin!
That's exactly why I run them dry as a matter of routine. No guess work or decisions to make.

 

[Mas]

Re: Four stroke short term storage

and to religiously run a good stabilizer

I agree! Close the vents and use a good stabilizer! I do not run the carbs dry. Just use you boat more often!

MAS

 

[Sea Rider]

Nonsense Tech Question

Nonsense Tech Question

Keep in mind that you can't run the bowl completely empty; The motor will stop from fuel starvation when the bowl is down about half way, but it does help.

If you state that can't run the bowl completely empty; when the engine is about to die from fuel starvation and the choke is completely pulled and closed again while accelerating the engine will revive again, if you do this process again and again where is the engine obtaining it's fuel, from the rest of the carb bowl, from gas filter or from both ? What are your ideas ? Is there any problem by doing this ?

If my 2 strokes engine is used frequently just disconnect fuel hose an let die from fuel starvation while it's being water flushed, if it will not be used for several days, weeks would preffer the second option, that is a dryer bowl & gas filter because of the remaining oil issue

Happy Boating

 

[pvanv]

Re: Four stroke short term storage

Think of the carb as a cup with a straw in it. But the straw doesn't contact the bottom. You can't possibly empty the cup with the straw, since it doesn't draw from the very bottom. If you really want the carb dry, run it out, and then open the drain to get the final bit of fuel out.

 

[TOHATSU GURU]

Re: Four stroke short term storage

Here's the thing. You are trying to get the gas level below the jets so that they don't clog up. You don't have to get every drop of fuel out of the carb. Also, fuel stabilizer has its place, but not used in small containers of gasoline. Use fuel stabilizer in built in tanks. Any portable tank or tank on an engine should have the fuel emptied rather than stabilized. It is a waste of stabilizer on such a small amout of fuel. Throw the $1.00 worth of gas away or use it in something else.

 

[pvanv]

Re: Four stroke short term storage

TG is absolutely correct. We advocate that our customers keep some stabilizer in the fill can (that's used to top up the motor's tank), just as a belt-and-suspenders approach. That way, any fuel used, either today or next month, has a better chance of still being good.

For a few days of non-use, running the carb down is fine. Certainly won't hurt anything.

I still advocate draining the carb bowl if planning on any length of down time. Sludge in the bottom of the bowl, while easier to clean out, isn't much better than clogged jets and emulsifier tubes, as it can get drawn into those passages.