Float valve sticking in 2 stroke outboard

[superdave1984]

This little Merc 25 runs like a champ. AFTER I pull the carb and unstick the float valve. If it sits a few days the needle valve sticks. Should I be running the carb dry after each use? I have read passionate opinions on both sides of this question. I don't understand why it should be needed since there's oil in the gas and that should keep all the carb parts well lubricated. The fuel is not evaporated from the bowl as it starts right up and runs for about long enough to get 50 feet from the launch. I could see the thing sticking if it had evaporated and it dried out. This carb has been disassembled and cleaned well twice in the last month. I did not replace the needle valve as it looks perfectly fine.

[Clint]

You said that you did not replace the needle and seat because it looked fine. I would suggest you either go ahead and replace it or look at the needle with a very strong magnifying glass. I rode Yamaha dirt bikes for many years, and the needles would get a really fine ridge where it sat in the seat. Just enough for the needle to get a little bit dirty and would then stick.

For as inexpensive as a kit costs, it makes sense to eliminate the possibility of it leaving you stuck somewhere and have to make it to the dock on the trolling motor.

Don't ask me how I know that.

[scout-j-m]

I think the needles kind of have a point where the rubber tip just goes bad. I've never actually seen one that looks worn or grooved but many that either don't seat well or constantly stick like yours. I know carb cleaners and stuff with alcohol in it can cause rubber parts to expand and shrink and mess them up while looking fine to the human eye. Are you using ethanol gas and/or any additives like Seafoam? Either way, the needle shouldn't stick after just a few days of sitting.

I sometimes run the fuel out of the carb but only if I feel the motor may sit a while like in the winter time, but I also use non-ethanol and typically add fuel stabilizer. I think running it out of a single carb motor is a personal preference but perfectly fine if you choose to do it. I probably do lean more towards not doing it as I feel like having the bowl full leads to less evaporation and less varnish build-up. I'm not a fan of doing it to multi carb motors as I don't like the idea of one bowl running dry first and not getting any lube to that cylinder while the other carbs use their fuel up. Probably not a big deal but as the motor leans out as fuel gets low the rpms do tend to climb for a few seconds before totally starving out.

I'd say replace the needle and the seat(if the seat isn't a pressed in one). I would imagine it would be a cheap fix, but I know those 25 Mercs have expensive carb kits so maybe the individual parts are high too.

[DockShootinJack]

Those little problems like that can drive you crazy

[superdave1984]

You said that you did not replace the needle and seat because it looked fine. I would suggest you either go ahead and replace it or look at the needle with a very strong magnifying glass. I rode Yamaha dirt bikes for many years, and the needles would get a really fine ridge where it sat in the seat. Just enough for the needle to get a little bit dirty and would then stick.

For as inexpensive as a kit costs, it makes sense to eliminate the possibility of it leaving you stuck somewhere and have to make it to the dock on the trolling motor.

Don't ask me how I know that.

Probably the way to go in this situation. And I currently don't have a trolling motor, just a home made paddle. ow just have to get the correct carb kit. And, of course, there will be 100 things in it that I won't ever need because it is a kit for 35 different carbs.

[superdave1984]

So it appears the seat is pressed in. I can't seem to get it out. I have not tried very hard as it seems fragile to me. I am just going to clean it really well with gumout and a pipe cleaner and get a new needle valve which I was able to find online for about $21 + shipping. First I am going to clean, reassemble, fire up the motor and let it run a little bit, then pull the fuel connector and let it run out as much as possible from the carb to allow the needle to (hopefully) unseat. I will be out of town for the next couple days so Saturday we will see if it worked.

[DockShootinJack]

I would think there are certainly videos on YouTube about taking the seat out. Never hurts to watch 2 or 3 to make sure they are all saying the same thing

[TheGrandPoohBah]

Several years ago I had a "Mini Mac" chain saw that would not crank. I took it to a local small engine repair, guy asks me if I ran all the gas out of the carb before I put it away. I said "No". He said "There's your problem, old gas has gummed it up, you gotta burn all the gas out of it". Left it with Him, picked it up a couple of days later, ran great.
Couple of years go by, chain saw would would not start, I brought it back to the same man at the shop, said it would not start. He asked "Did you run all the gas out of the carb before you put it away". I proudly replied "Yep, I sure did". He said "There's your problem, everything has dry rotted in the carb, you gotta leave fuel in the carb".
That was then, now I work on my own stuff, but the game is still being played out there.
Here's how I avoid the BS. I run Mercury Quickare Fuel Stabilizer year round in all of my small engines, including my Mercury Outboard, never a problem. One ounce to 10 gallons of fuel. A bottle of it from Walmart or Amazon treats 120 gallons of gas for around $8. I keep my tanks full of treated fuel, my pressure washer only gets run once or twice a year, never a problem after nearly 20 years of doing this. Regular gas, under 10% ethanol. Around here, non ethanol gas is a buck more per gallon, and many question the freshness of it due to a lower level of it being sold.
I am rolling with what keeps working for me.
Last year, I fixed my neighbor's generator, He always ran non ethanol gas in it, never a stabilizer, and it had not been started in at least 3 or 4 years. The gas tank had a coat of tar looking goo all in the bottom of the tank, and throughout the system. What a mess. Cleaned the tank, new fuel lines, cleaned the carb, He is back in business. I see this all the time. There is no magical cure for over extended storage. If you run them frequently, with good fuel you will probably be fine. If not run frequently, fuel stabilizers may buy you some time, maybe a year, maybe even a LITTLE more.
I have seen gas from a closed gas can that was a couple of years old that you could not light with a match.
How can you run with that?
Rant over...

[DockShootinJack]

I have a bunch of the old Coleman lanterns and lamps that run on white gas/ Coleman fuel. When I would find them places if they had fuel in them they would have a layer of varnish in the tank and plugging up all the orifices. Denatured alcohol would break it up

[TheGrandPoohBah]

I have a bunch of the old Coleman lanterns and lamps that run on white gas/ Coleman fuel. When I would find them places if they had fuel in them they would have a layer of varnish in the tank and plugging up all the orifices. Denatured alcohol would break it up

Yes it will.
Another trick my Grand Daddy taught me long ago was to clean inside gas cans, put in a big hand full of clean gravel in the tank with a little gas and sling it around every which a way and pour out on a big ant bed. Works on small boat gas tanks, too.
Years ago, the wife had a copper bottom steam kettle that looked rough inside. I put a hand full of gravel in there with some water and dish soap, slung around and around, poured out, rinsed, voila - clean as a whistle.
Come to think of it, my Mercury Manual near the front discusses the importance of cleaning the outboard's gas tank on a regular basis.