The Debate is run it empty or not ?

[Joe Reeves]

???----Why toss in the comment on cars ?-----The issue is MIXED fuel / oil sitting in a carburetpr for extended periods.

Yeah racerone.... but when driving behind him, one sort of gets a good idea where that excess pre-mix goes!

 

[redneck joe]

This is the most correct reply in this thread.

Lots of misconceptions on both sides.

​If you have oil injection you'll fill the carbs with oil if you run it dry like that.

​While there's a possibility you could score a piston, I've never heard of it happening, and there's a bit of extra oil that hangs out in the crankcase anyway, so it would take a little while to use it up.

​Running it dry doesn't empty the carb, it only lowers the fuel level, so it helps, but it's not perfect.

Removing the drain plug in the carb will typically be the only way to get all of the fuel out.

​You'll have people say, "I never run it dry and I never have issues".

You'll have people say, "I always run it dry and I never have issues".

​You'll have people say, "I do it both ways and always have issues".

​You'll have people say, "I only run E-0 and never have issues".

​You'll have people say, "I only run E-10 and never have issues".

​You'll have people say, "I run both and always have issues".

​You'll have people say, "I always run XXX miracle in a can gas additive and I never have issues".

​You'll have people say, "I never use a gas additive and I never have issues".


I could go on and on

​So do whatever it is that works for you, or makes you feel good, then move on to the next major life decision.

 

[interalian]

Yeah racerone.... but when driving behind him, one sort of gets a good idea where that excess pre-mix goes!

I always burn the leftover mix in my X5 when hard water season starts. Probably about 400:1, but I don't sweat it.

 

[racerone]

For many , many years now I have concluded that most folks really do not understand what happens to the gas / oil once it goes through the carburetor.----Do not understand what happens with oil inside the crankcase.----The lubrication is NOT an instant thing and oil stays in the engine longer than most people think it does !!!

 

[cfauvel]

racerone,
I actually don't know the goings on inside of the crankcase as far as lubrication...so wouldn't mind some direction in that point...does the fuel/oil mix puddle at the bottom of the crankcase?

 

[racerone]

For one thing the gasoline portion amd oil portion seperate.--Oil does not vaporize like gasoline does.

 

[jbuote]

I'd envision it more like a spray... The vaporized fuel/oil mix coats the internals in the crankcase before it makes it's way into the combustion chamber.
​Kind of like spraying the mix with a spray bottle.. Not all the fuel/oil mix gets to the combustion chamber. Some sticks to the parts lubricating them.
If you ran straight gas for a bit, it'd "Wash" the parts removing the lubrication..
​So it wouldn't be an instant "No Oil" condition per se', but you want to maintain the oil part too to "Keep" the parts lubricated..

​How long to run without oil to "wash" the parts? Can't say.. Pretty quick I'd guess, but running a fuel/oil mix and disconnecting fuel supply shouldn't "Hurt" the engine.
​If it did, then running out of gas in the tank would be catastrophic, and we've all done that I'd think.

​But heck.. I could be wrong, so I'm watching the debate too..
​Love to learn and hear opinions and experiences..

​(edit: didn't see racerone's post above.. Good info!)

 

[ondarvr]

As he said, they separate, not 100%, but they do. The gas vapor easily moves into the combustion chamber, the oil tends to drop out and cling to surfaces, or at low RPMs it can collect and sort of pool up, at higher RPMs it moves through the motor faster, with less collecting in the crankcase, but far more oil is cycled through the motor.

​So by running it dry at an idle, the chances of scoring a piston or cylinder is low.

 

[Fed]

Riddle me this, why don't the motors eventually fill up with oil inside the crankcase, how is it regulated?
Does it coat everything until it starts getting flung around then gets pushed up with the hurricane of fuel air?
It must be violent in there I've had escaped wrist pin bearings go from under the piston through the motor & out the exhaust, you'd think they would just lay in the bottom of the crankcase.

 

[ondarvr]

Nobody say it's stays in there, and the pooling description is just to say that a small amount can collect in the crankcase, it's one reason 2 strokes have a reputation of not liking to idle for long periods of time. And after idling for extended periods of time they tend to smoke a bit more when you throttle up.

 

[Tony T.]

​I've run E-10 for 25+ years, still waiting for all the horror stories to come true, same with all my friends. Is it the same as the other stuff...no, but just get used to it and move on.

​By the way, I do nothing, I turn off the key at the end of the day and the next time I use the boat I turn it to start, no gas additives, no running it out of fuel or draining the carb, nothing.

​The boat I normally use the most hasn't been started in almost 2 years, so I'll see how it goes when I do start it. My longest length of time was 7 years, hooked up the battery and fresh gas can, it started and ran fine for the rest of the season.

​There were plugged up carbs and aged fuel lines around long before E-10 was on the scene, the E-10 just destroyed the cheap components quicker, the better quality stuff appears to hold up fine.

I'm glad the E-10 has worked out for you, but here in my area just recently a boat motor mechanic/friend of mine bought a 3 gallon gas fuel tank and it was a Shoreline marine gas/squeeze pump line (runs about $40 bucks here just for the gas line itself).Any how he purchased both off craigslist for $35 bucks, according to the seller it was bought new last year.

The seller had left old gas in the tank, also in the fuel line. kinda long story short here but my friend said well I got rinky-doo on that deal the tank showed sticky residue in one corner of the E-10 breaking down with also the o-rings and gaskets breaking down to where it would not seal off to hold pressure, also the clear inner lining on the fuel line was breaking down and starting to come apart.

So I don't know what to say except thank goodness you are not having any problems but you can ask several mechanics in my area what they think about our today"s gasoline and you'll get a ear full of cuss words right quick.

Tony

 

[ondarvr]

There is cheap crap being made in China and other places and they'll stamp anything on it as a label to meet any spec or code, there is no reason for a fuel line or a tank to fail prematurely from E-10. How do you think every car in the US has held up since about 1990 when E-10 was first introduced, do they all fall apart in the first year..no.. the technology to make stuff last isn't a secret, it's been around a long time. Any manufacturer that uses cheap parts, or happens to buy fake parts, is responsible for the failures, not the fuel.

​I'm not saying I love E-10, but put the blame for bits and pieces that fail on the right shoulders.

 

[Tony T.]

I agree with you on products being cheaply made these day's but I also I agree with other mechanics and myself that the gasoline we are forced to buy is cheap crap also.

Tony

 

[ondarvr]

E-10 is a good target for scare tactic marketing and blaming things on, and it's not without reason, but we were one of the first places in the US that was required to use it, we went through the same uproar, but it was so long ago now that people just learned how to live with it and it's not even talked about much.

​

 

[Tony T.]

As a kid one of my jobs/chores was to keep the lawn mowed, I remember we had this old 5 gallon metal gas can to fill the lawn tractor up. Heck I didn't even know what fuel additive was back then, so that gas can would set all winter in the shop half full of gas and the next spring I use that in the lawn tractor at first mowing. This was back in the early 70"s when we had real regular gas. I can't do that today with out treating our gas of today with additives.

I may have to live with it but I don't have to like it.

Tony

 

[ondarvr]

I leave gas all the time for a year and use it with no issues, I have a bottle of Sta-Bil, but it must be 10 years old by now, it's ugly and discolored, it's sits unopened on the shelf.

​I started working on 2 stroke outboards in the 60's, they fouled plugs, smoked and carboned up badly on that leaded fuel and old school oils, what we run now is much better.

​Again, I don't think E-10 is a great product, but it's what we have and it's not going anywhere, complaining about it doesn't help much, and just changing a few bad habits makes it kind of a non issue in small boats.

 

[jimmbo]

This thread is almost as much fun to follow as a thread on TCW-3 oils.

 

[fhhuber]

???----Why toss in the comment on cars ?-----The issue is MIXED fuel / oil sitting in a carburetor for extended periods.

The proper oils for pre-mix have an additive to help improve shelf life of the fuel.
So if you don't need to run your carb dry in your car, you definitely don't need to run your carb dry in your boat.

Maybe drain the carb when storing for 3 month or more. Not much if any point in draining it or running it dry if you are using the boat more often than your lawn mower.

 

[ajgraz]

racerone,
I actually don't know the goings on inside of the crankcase as far as lubrication...so wouldn't mind some direction in that point...does the fuel/oil mix puddle at the bottom of the crankcase?

Some of that depends on what EPA laws were in place at the time. The original powerhead on my old 1978 70hp 3cyl Merc had a tube coming out the bottom of the crankcase specifically for the purpose of dripping that unburnt, pooled-up oily stuff directly into the water. Always a huge sheen behind the boat. When I replaced that powerhead with a 1988 powerhead, they had come up with a way to route that tube back into the carb throats to at least give it a chance to get burned first. So less sheen, but more smoke...though synthetic blend helps with smoke.

But anyway, as to running the carbs empty...used to do that on that old motor religiously, because if I skipped even one time, I would have to remove the carbs to clean out the varnish and gunk from today's moisture-absorbing fuel. Even when I did run carbs empty regularly, I still had to disassemble and clean the carbs at least twice a year.

But then I got a fuel/water separator filter, and I haven't had to disassemble or clean the carbs in over 10 years, and that's without ever bothering with running the carbs dry. And now that I have another boat, the old one sits for months at a time...but fires up no problem every time.

It's water in the fuel that's the killer, in my experience. Ethanol is a water magnet. So: if you don't have one, get a fuel/water separator filter. It will make you believe in magic.

 

[Bonaventure]

Yeah, you drive your car a lot more often than most people use an outboard. If you use the outboard every day, then no don't bother shutting off the fuel and running the engine until it stops.

I have always done it, but I only operate portable outboards with a single carburator, which is removed from the boat at each use.