Carb Cleaning Options after Storage?

[v10enomous]

I didn't run my 1999 Mercury 25 out of gas before the long bitter cold winter. Idles roughly now and will stall without pulling the primer every 45 seconds or so. What are the simple things to try for carb cleaning before taking it somewhere ?

 

[bilge rat jim]

First, despite what others have said, I don't recommend running the engine dry- There is always the slim possibility of creating a lean condition at the end of the fuel and damaging the internals. Much better, in my opinion, to just use a storage product in the fuel, and then draining the fuel system.

These are about the simplest carbs around and cleaning is easy- remove the carb, completely disassemble, clean the body and parts in Dunk, or better yet, have the carb body cleaned by a shop that has an ultrasonic tank, and reassemble using ALL the pertinent parts in your carb rebuild kit.

 

[jimthorley]

my carbs were blocked as the outboard had sat for at least a year before i bought it.tried running with seafoam and mystery magic oil outboard. was serviced fully by my self.and in the end took carbs off got sonic clean and problem fixed the outboard had refused to even get me up on the plane had out on Monday first time since putting carbs back on and what a difference .i have just started the practice of running outboard out of fuel. bilge rat jim now you have me thinking as a lot of info on the web is to run dry and drain bowls if outboard going to sit even for only 3 days without running. i have just started using a new outboard mechanic and he was saying hes booked solid with carb problems worst year hes ever seen for carb problems he even told me not to use the sea foam?? is he wrong?

 

[papyson]

if you run carbs dry then run the motor at 2k or below....then press the choke as it starts to die....its the clowns you see at the launches that run the motors at screaming rpms that are subject to damage...thats my opinion anyway....but i run carbs dry for 55 years til i went with efi..you never know when something will happen and the boat will go unused for a long time...been there done that

 

[fastjeff]

.."its the clowns you see at the launches that run the motors at screaming rpms that are subject to damage..."

Right you are--an especially with multi-carb motors! If all the carbs ran out of gas at exactly the same time it wouldn't be as bad, but that's never what happens; one of them will go dry as the motor keeps screaming...


Jeff

 

[jimthorley]

.."its the clowns you see at the launches that run the motors at screaming rpms that are subject to damage..."

Right you are--an especially with multi-carb motors! If all the carbs ran out of gas at exactly the same time it wouldn't be as bad, but that's never what happens; one of them will go dry as the motor keeps screaming...


Jeff

Yes i know the type .i just let her run out at idel speed.mine has the 4 carbs and are a bit of a job for a novice like me.its hard to beleive such a small amount of debris in the carbs causing so much bother but i have experianced it first hand and the cleaning bill to go with it.i will continue to run it dry each use.thanks for clearing that up for me appresiated

 

[v10enomous]

Ok... all fixed. Carb rebuild, fuel line and primer bulb, plastic fuel filter bowl and labor $396 total including tax. She runs like a top now but the place that fixed tells me that the fuel starts varnishing within 3 to 4 weeks of inactivity because of the ethanol. What are the best additives and practices to prevent this from happening again ?

 

[jimthorley]

Ok... all fixed. Carb rebuild, fuel line and primer bulb, plastic fuel filter bowl and labor $396 total including tax. She runs like a top now but the place that fixed tells me that the fuel starts varnishing within 3 to 4 weeks of inactivity because of the ethanol. What are the best additives and practices to prevent this from happening again ?

lots of diffrent advise going about on this subject i was using seafoam but my mechanic said best practice is to let the outboard run out of fuel by disconnecting fuel line and let outboard run dry it can take 5 to ten mins dependant on engine dont rev engine hard to get it to run out once thats done unscrew carb bowl drain screw and let any fuel drain out best to have a cloth to catch any fuel and if you do this everytime you wont get carb problems this is the practice i have started.and lots of people have agreed best thing to do a few will say diffrent but no fuel no tarnish makes sence to me glad you got it in the end i was the same

 

[racerone]

Run the carburetors dry !!!-------It is the best thing you can do to keep them clean.---And do not worry about one carburetor running out before the others.--------There is lots of oil inside a running motor and it does not disappear instantly once fuel stops coming in.

 

[bilge rat jim]

Ok... all fixed. Carb rebuild, fuel line and primer bulb, plastic fuel filter bowl and labor $396 total including tax. She runs like a top now but the place that fixed tells me that the fuel starts varnishing within 3 to 4 weeks of inactivity because of the ethanol. What are the best additives and practices to prevent this from happening again ?

Meadow muffins! Residual gasoline in a fuel system component such as a carb causes "varnish", because when the fuel evaporates, it leaves the solids behind. Ethanol contains virtually no solids, so does not contribute to "varnishing". If you doubt this, pour an equal amount of gasoline and ethanol in separate glass dishes, and let them evaporate. You will find a layer of solids in the dish with the gasoline, but none in the ethanol dish.

The key to keeping the varnish from a device is to remove the fuel. Even if you run the engine dry, there is still fuel left in the float bowl, which will eventually evaporate, leaving solids. If you drain the device, there is no fuel left.

 

[galamb]

See, even we can't come to the same conclusion.

I run stablizer all the time PLUS fresh fuel each time out (pretty much) - but not that way over priced "ethanol" stablizer - I run the no-name junk from the local auto parts place.

The stablizer will keep the fuel in the system (carb, filter, lines etc) ok for the time in between running "during the season".

Since I run either 3 or 6 gallon tanks (depending on how much I plan on running), whatever is left over at the end of the weekend (or whatever) and I know I won't be out again for a week or more, the leftover gas goes into my truck (even the 50:1 mixed stuff - truck don't mind and it's only maybe 2 gallons worth into my 32 gallon tank, so more like 500:1 by the time it mixes with the gas in the trucks tank - no issue)

That way next time out will be with fresh gas.

I'm on the side of the fence that believes that ethanol is over hyped - there is NO issue running ethanol gas in an outboard whether it's a newer or older model. I ran E-15 in all my motors (which are 1986 thru 1991 models) for two years with zero issues. Ran E-10 for many years before than and since, again "no issues".

Yes, ethanol will cause "phase separation" if it sits and attracts moisture. But any gas that sits "gets old" and don't burn worth a crap.

Since long before ethanol was added to gas it was used (at least one of the products) to "clean carbs" and its also used in gas line de-icer - so while it's ok for cleaning carbs and for preventing gas line freeze in northern climates it's not ok to run through them mixed with gas - seriously??

In the 70's it was "unleaded" gas that was going to kill every motor out there. Today it's ethanol (although even that is starting to die down). Just wait a few years and there will something else to worry about but "some product" will be on the market (at great cost of course) that will prevent the ill effects of the "yet to be discovered" next engine killer.

 

[v10enomous]

I found some SMB Ethanol Fuel Treatment in Dollar Tree so I picked up a bottle and found the SMB website but the product I bought is nowhere to be found on the site.

http://smbintllc.com/index.html