Gummed Outboard

Larry J

Larry J

Active member
Like a dummy I let the gas sit in my Honda outboard all summer. Motor runs, but idles way down every 5 to 8 seconds or so then picks back up. Much better since I added new gas to the old 1 gal left in the tank. Three Honda service depts say carb and fuel system need dismantling and cleaning. Is there nothing that can added to the gas to clean out the system?
 
I had the same problem with the outboard i bought last season. The guy i got it from had it sitting for about 6 months. I used seafoam and then added startron to every tank after that it got me through the rest of duck season. Then about a month ago I took it to my local marina to have the carbs done and gas lines changes and now it runs like new. If I had it to do over I would have had the carbs done from the get go. It made a big difference.
 
Getting it properly serviced now will save you a new motor later in the season.

You can save yourself some money by changing out the fuel lines & flushing the tank yourself.

If it's a plastic tank, replace it with a new one since the Ethonal has already begun to breakdown the interior of the tank anyway.

Take out any in-line filters & replace with a Racor water/fuel separator.

The plastic in the in-lines in the first componant in the system to start, well basically decaying.

Let the mechanic go threw the carbs.

Used Sta-Bil, Sea Foam or Startron to the fuel from this point forward.

At the end of the season, empty your tank, blow out lines & fog your cylinders.

Some say fill the tank & add an additive for long-term storage (believe it or not, it is now considered 30 days with ethanol).

Most tanks on our duck boats are smaller so empty them & put it in your snow blowers LOL.

Ethonal is the true evil to the marine industry.
 
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My new Nissan 20hp won't even run on ethanol. The first time I put the stuff in my tank I thought my new motor was defective. Dumped the ethanol in my truck tank and put pure nonethanol gas in my boat tank and it's been running like a top ever since.
 
Dave, in Nothern VA, it is pretty safe bet Larry used gas with ethanol in it.... we either have to buy at the marina, or drive 1.5 hours (last time I looked on Pure Gas website) to find anything without ethanol. I am resigned to using it now, diligent in my use of Startron and Seafoam in every tank. But you are right, Larry did not indicate that he used ethanol. Would the fix be any differnet if it was just varnish from the old pure gas?

Dave
 
Would the fix be any differnet if it was just varnish from the old pure gas? Dave
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It may be non-ethanol fuel, but just assumed it was since the problem he described is the #1 problem for O/B's & small engines @ that time.

As for the fix, I would go through the same process I described above & replace the lines & filters.

I've seen to many varnished up carbs cleaned just to go out on the first time & have the same issues.
 
Jeff, you mentioned the plastic tanks breaking down from the ethanol? I know that the EPA just changed the rules for tanks, thought it was something about expansion, and fumes escaping? Did the materials also change that might be compatible with ethanol now? Do they still make metal tanks for small OBs? Would a metal tank be better?

Dave
 
Alot of us guys down here switched to aluminum tanks just to take a big hunk of plastic out of the equation.

The plactic tanks get a slime up on the interior which ultimately ends up going through your engine.

The little cheap in-line filters are even worse when they begin to desinagrate.

We've seen pieces parts of the screens & plactic supports end up inside the carbs.

I've always run a Racor since my offshore fishing days.

Even using these with plastic tanks, we're seeing the filters clog up from the plastic tanks.

Took out the plastic tanks, no more problems.

I know there was talk about a material change, but if you have removable tanks, spend the $100 bucks & get an aluminum one made.
 
Thanks for all the response and suggestions.
I have to assume that the fuel was E10 as I bought it at the local Shell.
I did some quick research about ethanol and plastic tanks. iBoats suggests that ethanol doesn't degrade plastic tanks and they even suggest staying away from aluminum tanks.

http://www.iboats.com/basics/ethanol_fuels.html

Water (condensate) in the tank causing the ethanol fuel to phase seperate seems to be the biggest problem. Maybe that's the "slime" some see in plastic tanks.

I'll definately get the outboard serviced and take all the precaution steps suggested. Thanks.
 
Larry,

Had issues with my Honda after a few years of little use. Does yours have the drain tube and a nipple on each carb bowl, if so drain the carb by opening the drain set screw, after draining hold the tube up and squirt carb cleaner into the tube until it fills the bowl and comes out the atmospheric vent, close the set screw and repeat with each carb bowl. let the cleaner sit for a day or two, drain all carbs and take it for a ride. That took care of my issues. I use Seafoam now also.

George
 
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Would the fix be any different if it was just varnish from the old pure gas?
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Dave,

Guess we are still lucky, in this local area, we have non-ethanol readily available.

The fix for old gas/varnish would not be near as extensive as the fix for ethanol damage. For instance, I have never had to replace a plastic tank. Some of my tanks have been in service for over 20 years.

As a side note, I rarely if ever worry about "old" gas, "old" being a subjective term. [/font][font=Verdana,Arial,Helvetica]In my Chuck Huff, [/font][font=Verdana,Arial,Helvetica]I have a plastic tank hooked up to a two stroke 15hp Yamaha. It has sat unused in my driveway for 4 or 5 months ([/font][font=Verdana,Arial,Helvetica]since spring). I pumped the bulb up Sunday and pulled the starter rope two times, fired right up.

Back in the mid 60's thru the mid 80's part of my employment duties included "small engine mechanic" I worked on full size engines (diesel and gas) as well, but serviced many many small engines for a rental fleet. Much of this equipment was very seasonal and would sit for long periods of the year. We always kept fuel in the carbs, lines and tanks at all times. The only times we would have fuel related problems was when the system leaked and subsequently dried up.

When a fuel system or a portion of it would dry up, over time on it's own, only then we would have to deal with varnish, shrunk gaskets, dried out and cracked diaphragms, cracked fuel hoses, etc.

If we drained the fuel system, we did not have any varnish problems, but the dried up gaskets, etc. would still often happen.

I realize that things are in fact a bit different now days. Better gaskets, better fuel lines, better diaphragms,------ coupled with more destructive fuel. That said, I haven't changed my fuel habits and so far anyhow, it continues to work for me.

Again, I may be more fortunate in that I am still using "real" gas with out any ethanol. I have no argument with others experiences and from what I hear, I may be in the minority (as to not having any fuel problems).
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A poorly built, non-vented aluminum tank will do exactly what they described.

Looks like they fixed the problems with the older materials in the plastic tanks, though I still prefer aluminum.

As far as the glass takes, back when the E10 came to Florida, the shipyards around Port Canaveral & Sebastian were full of larger vessels getting their decks ripped off.

If nothing else, a Racor filter & fuel additives go along way nowadays.

A $30.00 dollar bottle of Sta-Bil is cheaper than replacing an engine.
 
Even small engine manufacturers agree that ethanol is shit. Briggs and straton and a couple others have started to produce their own gas for sale by the 1 or 5 gallon at local hardware stores. They also suggest that if you use ethanol gas to put ethanol sta-bil in it, but still not to store it for more than 2 weeks.
With outboard racing I had to waste the money to go to Aviation fuel or Racing fuel. The higher octane does nothing for a 2 stroke outboard because they are relatively low compresion engines. But ethanol gas won't gas our fuel test for illegal addatives since it's basically grain alcohol.
 
On the advise of my small engine mechanic I now run everything (up to and including my 4 wheelers) dry if it will be more than a couple of days between uses. No more problems so far. I also use StaBil
 
Larry,
ask at the shop you choose if they use an ultrasonic cleaner to get the carb clean. Not all shops have one and they help a lot to get the small inside passages done right the first time.

We dont have one at the shop but are looking at one big enough for QuadraJets. They are getting very hard to find good cores for and rebuilds are starting to look cost effective.
The Honda guy I know loves his ultasonic cleaner.
Fuel stored in these has def. been a problem if the gas wasn't treated.

Bob
 
Larry,

Had issues with my Honda after a few years of little use. Does yours have the drain tube and a nipple on each carb bowl, if so drain the carb by opening the drain set screw, after draining hold the tube up and squirt carb cleaner into the tube until it fills the bowl and comes out the atmospheric vent, close the set screw and repeat with each carb bowl. let the cleaner sit for a day or two, drain all carbs and take it for a ride. That took care of my issues. I use Seafoam now also.

George
Click to expand...

Good stuff. I'll look this weekend.
 
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