# 2005 Yamaha TLRD 40 will not idle



## Swamp (Jul 12, 2010)

Sounds like a fuel supply issue to me. Check the inline filter if it has one. That is a carburated engine right? Check the hose that runs to the carb and make sure it is not pulling air, doubtful considering the age but with the e-fuels if it's rubber it's suspect. Buy an OEM manual, you will need it eventually anyway. Drain the carb bowl (catch the fluid if you can so you can look for water or debris). Remove and dismantle the carb to clean. Oh and my personal favorite that I hate to admit to is to check the fuel line connection to the motor. I've "almost" had it connected correctly and the bulb was nice and hard but only a trickle of fuel was getting into the system.

The fuel line connection is the easiest but most embarrassing. A clogged fuel filter is very common. The carb is probably the most likely, a little more trouble but doable. You may have to remove other "stuff" to pull the carb(s). Again get a manual.

These are principles for just about any "small" engine. The fact that it will fire up is good.

Swamp


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## 8loco (Feb 12, 2012)

What is the going rate to have the carbs cleaned at a marine shop?


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## 8loco (Feb 12, 2012)

Turns out it was water in the gas tank. I think I will start driving to a marina and buying e free gas.


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## Swamp (Jul 12, 2010)

let me guess, it clogged up the filter and/or got into the carb? Glad it was not a major issue. While getting ethanol free gas is a great idea use a fuel stabilizer anyway or if you can't get ethanol free definitely use it. Don't let your gas sit forever, even "good" gas will get water in it. Like you need another excuse to go out and burn some gas right?  There is also a debate whether or not keeping your tanks full helps with avoiding condensation. Down here, I'm not so sure. Further north I'd buy that. Can't hurt though.


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## 8loco (Feb 12, 2012)

My skiff gets used twice a week and I only have a 15 gallon tank. So new gas is constanly flowing through it, not quite sure how that much water got into the tank. Regardless the yearly service needed to be completed and the carbs needed a ultrasonic good cleaning. All is well with the boat and I already bought fuel stabilizer and plan on switching to e free gas.


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## Creek Runner (Sep 1, 2011)

> let me guess, it clogged up the filter and/or got into the carb?  Glad it was not a major issue.  While getting ethanol free gas is a great idea use a fuel stabilizer anyway or if you can't get ethanol free definitely use it.  Don't let your gas sit forever, even "good" gas will get water in it.  Like you need another excuse to go out and burn some gas right?   There is also a debate whether or not keeping your tanks full helps with avoiding condensation.  Down here, I'm not so sure.  Further north I'd buy that.  Can't hurt though.


It doesn't, actually makes it worse. 

Get a good Fuel water Separator, Yamaha or Racor would be my choice. I prefer the Racor because of the clear bowl easy to see if you have water in the gas. Also make sure your stabilizer is alcohol free. Yamaha Ring Free would be my suggestion.


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## Brett (Jul 16, 2008)

Biggest cause of water contamination in ethanol gas is leakage from top of tank fittings.
Vents and fills on the boat allow leakage due to gravity and the direct pressures created
by hosing off the boat, wind driven spray and when running in seas big enough to drive water
into the overflow vent on the side of the hull.


previous post: Fuel Tank Leaks


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## Swamp (Jul 12, 2010)

> > let me guess, it clogged up the filter and/or got into the carb?  Glad it was not a major issue.  While getting ethanol free gas is a great idea use a fuel stabilizer anyway or if you can't get ethanol free definitely use it.  Don't let your gas sit forever, even "good" gas will get water in it.  Like you need another excuse to go out and burn some gas right?   There is also a debate whether or not keeping your tanks full helps with avoiding condensation.  Down here, I'm not so sure.  Further north I'd buy that.  Can't hurt though.
> 
> 
> It doesn't, actually makes it worse.
> ...


LOL! I did say there was a debate! Let me guess which camp you are in?  Me I'm not sure. I think a dead empty plastic tank should not condensate readily. Aluminum or a half empty compared to dead full? Well like I said, I'm not sure. I will however agree with Brett that all of the causes he mentioned are real and to it's best to avoid them. One nice thing about portable tanks is they are easy to check for water and easier to clean out now and again.


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## DuckNut (Apr 3, 2009)

Swampy - I am in Brett's camp. But I can tell you with certainty that if you have air in a can it will condensate before one that has no air. The air will change temperature much more readily than liquid.

Take a cold half full can and put it in the sun to warm up and there will be condensation in it. Although it will be so minute that it won't be an issue.

My father in laws van sat for a little over a year with a quarter tank of gas and after I got the battery charged the van ran. It ran rough but far better than I would have imagined. Ran fine after I filled it up.


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## Brett (Jul 16, 2008)

I found from my own experience, that a garage kept boat
with a portable fuel tank, fill/vent properly protected, has no ethanol problems.

Prevent gravity/pressure leaks of water into the tank
and the fuel doesn't become phase separated.

previous post: Vent Cover

If you really want a scare, do a seal test on your fuel fill.
Open the fill, wipe the inside of the neck and hose dry.
Close the cap and then spray the fill cover with a hose
just like when you clean your hull. Then pop the cap
and look at the water droplets inside the neck and fuel hose.

                                 :'(


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## Swamp (Jul 12, 2010)

Ducknut, I think I misunderstood you.  I though you meant keeping a tank _full_ made it worse.  The thing I'm not so sure about is if a tank buried under the deck of a boat will have time to cool below the dewpoint before the temp comes up again (down here in SW FL at least).  Maybe it could once or twice a year but then the dewpoint and humidity is usually low too so maybe not even then.  Further north, maybe even a hundred miles or so or further inland, I could see it happening readily.  I'm not a physicist so...

All of this makes me wonder if condensation is a factor then we may compound the problem by agitating the tank (like by driving to the ramp) before any condensate has a chance to vaporize again and it gets sloshed into the fuel.

I agree with Brett that if you can, then garage kept is best and that other factors are usually much more of a problem.

As far as the van is concerned, that may have had to do more with stale vs fresh gas than anything (been there done that too).  Now if it had unstabilized fuelil mix in it like our boats then I think you might still be cursing at it. Cleaning out a vehicle tank sucks.


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## Creek Runner (Sep 1, 2011)

> > > let me guess, it clogged up the filter and/or got into the carb?  Glad it was not a major issue.  While getting ethanol free gas is a great idea use a fuel stabilizer anyway or if you can't get ethanol free definitely use it.  Don't let your gas sit forever, even "good" gas will get water in it.  Like you need another excuse to go out and burn some gas right?   There is also a debate whether or not keeping your tanks full helps with avoiding condensation.  Down here, I'm not so sure.  Further north I'd buy that.  Can't hurt though.
> >
> >
> > It doesn't, actually makes it worse.
> ...


Yep I'm in that camp; of not keeping your tank full if you run Ethanol fuel (and it's not because of condensation), and to keep your tank full if your run non ethanol fuel.  Let me say that I don't have an issue with water in my gas in any of my boats, which have 6 gallon, 18 gallon, and 400 gallon tanks. But I use my boats regularly and none of them get ethanol fuel except the 6 gallon tank in my little boat. However I work on boats for a living and every year when springs hits I get half a dozen boats with water in their fuel, do to condensation and or ethanol fuel. And yes all of the points that Brett mentioned are valid, and cause water in the fuel which is about the other half a dozen boats that I work on that have water in the fuel (99.9% fuel vent). Also keep this in mind most people don't believe things until it happens to them. If what you been doing works for you then great keep doing it, if you have had a problem then might want to change it up. 

Stay safe
Tight lines


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## cutrunner (Jun 8, 2010)

Your problem is very apparent. The only clear solution i see that you have is to convert your motor to run on water instead of gas.


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## Swamp (Jul 12, 2010)

CreekRunner, I'd be interested in hearing why you feel a half empty tank of e-fuel is better than a full one. I could see the logic of wanting to use it all up before refilling. Like I said I'm still open to arguments one way or another.


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## cutrunner (Jun 8, 2010)

I second creek runner

Reason being is that you have to remember tht te tank is vented to atmosphere.
Wether theres alot of room for air in the tank or very little, its still open to the atmosphere, 24/7 day and night.
Like rust, it never sleeps..
Either way are all better reasons to try and use the boat.


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## Swamp (Jul 12, 2010)

Yes I get that and I agree for sure, the fresher the better. But why is a half empty tank better than full?


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## cutrunner (Jun 8, 2010)

I wouldnt say half as much as i would say 1/4.
What i believe it really comes down to is lets say one gallon of fuel can absorb and make one pint of water (just throwin numbers out here, nothing real)
50 gal = potential for 50 pints
10 gal= potential for 10 pints


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## Swamp (Jul 12, 2010)

Okay, so what you are saying is the volume does not really facilitate or restrict condensation but the greater the volume of fuel the more water it can potentially absorb because the amount of water absorbed upon equilibrium is a set fuel:water ratio. Right? I can see that logic. Not sure if that is what does or does not happen, or rather how long that equilibrium takes to happen (five days, weeks, months, or years?), but it certainly sounds plausible to me.


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## Creek Runner (Sep 1, 2011)

Swamp let me 1st say I am no physicist but I did do good in science in school, lol! ;D However I am a Master tech for Yamaha products and Master tech for Volvo Penta. I'm also certified in Mercury/Mercusier, use to be in Suzuki, use to be in OMC when they were in business, and have attended one school from BMC. The last Volvo Penta school I was in they actually had a gasoline/fuel nerd come in and talk to us for about 2 hours. So let me explain what I got from that mental enema and also from my experience as a marine tech.. Volume does facilitate and restrict condensation, that's why I said if I was running non-ethanol fuel  I would keep my fuel tank full. However the problem is that ethanol fuel is hygroscopic, which means it absorbs moisture from the air, not just condensation formation inside the tank. This is what Cut was talking about saying that 10 gallon would produce 10 pints and 50 gallons would produce 50 pints of water. These are made up numbers for example purposes only. In a small boat with a 6 gallon tank that is ran at least twice a month you will never experience what we are talking about. That's why most people on this forum discount what I'm referring to after all its Microskiff.com not Offshore only. But the problem does exists and it's very real in larger boats, and when I say larger 30-35 gallon tanks are probably half of the ones I see with water contamination. Take a glass jar, fill it about 3/4 full of ethanol fuel (not treated) leave the lid off and put a fan on it, come back 4 hours later and look at the results. 

Now let's keep examining a little further. The more ethanol fuel you have the more moisture it will absorb, but the more fuel you have the more moisture the fuel can hold before phase separation occurs. So again for example purposes only; you have 10 gallons of fuel it will hold let say 2 pints of water before phase separation begins, at which point water will begin to collect in the bottom of the tank, it doesn't stop there though every single bit of moisture it absorbs after phase separation begins goes to the bottom of the tank because the fuel is already holding as much moisture as it can. So there is no end to how much water can accumulate. Imagine having 80, 100, or 150 gallons.

Also just so there is no misunderstanding, I no longer work on boats for a full time Job. I do however still attend manufactures schools through various friends who own dealers.  I only work on a select few tournament guys (around a dozen) boats and I have about a dozen service contracts with some other clients for which I basically always make sure there boat is ready to run when they step on board sometimes that's only once a year. Other than that there are a few other jobs I will do as a favor to my regular clients. I did however work on boats full time when my dad owned his dealership and also was the service manager for 2 other dealers, and worked directly for Yamaha before leaving the industry full time. I have worked on everything from aluminum Jon boats to 100' sport fishers. I currently run a 14' stumpknocker, 19' STV, 25' Shearwater, and a 44' Formula. So I have a vast knowledge of all size boats, motors, and manufactures. 
I do not claim to know more than anybody else does, I only speak of knowledge learned from schooling and 1st hand experience of operating and working on boats, like I said in my previous post if what you or anybody for that matter has been working then great keep doing what you doing and catch some fish. 

Sorry for such a long post.


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## Swamp (Jul 12, 2010)

No need to apologize, great post!

I think we are on the same page about e-fuel chemically holding water and that e-fuel will hold X amount of water per volume of fuel(say one gallon) under a given pressure and temperature.  You used an easy example of 1:10, that works for me.  The more fuel you have, the more of a volume of water it can absorb if exposed to atmosphere or liquid water.  The ratio of 1:10 stays the same though.   Once the saturation level is reached water will separate out.

So here is where I start to question how a tank that is more or less full will or won't absorb water faster.  The vent hose is really the only ingress for water in the form of vapor or liquid since we assume the fill hose is shut and the fuel line to the motor is sealed too. Normally there should not be a whole lot of air flow into a tank with just one vent so the vent is going to be restrictive.  I'm only talking about vapor here, if you force water into the vent with a garden hose etc. then it's a mute point anyway.  I suppose the ID of the hose could have an affect on gas(vapor) exchange but I expect it would be minimal here.  Again I would think time is the real variable that that controls how much water absorbs into the fuel.  It takes Y amount of time for X volume of water supplied in the form of vapor to diffuse into the tank through the vent and then consequently absorbed into the fuel.  A greater volume or lesser volume of fuel should not affect the rate of absorption.  Now a full tank (as in a larger volume of fuel) is going to take longer to absorb the greater volume of water required to saturate it than say a 1/4 of a tank.  But the rate of absorption should be the same (ignoring changes in temperature, humidity, and pressure) the 1/4 tank will just hit saturation faster because the full tank will not be done yet because it requires more.

What I don't know is how much longer does it takes for the greater volume to hit saturation.  If it is significant then a full tank will have an advantage.  If it is not significant then you end up with a lot more "bad" gas you have to burn through or you end up not being able to dilute it as much if you top off your tank before running the motor.  The same holds true for water separation.  A smaller volume would saturate faster and then consequently allow water to start to separate out faster.  In theory a smaller amount of fuel would therefore have more liquid water in the bottom of the tank after the same amount of time as compared to a larger volume in an identical tank.  How much more, I don't know.  Again it depends on if it takes significantly more time to saturate the larger volume or not.

Condensation is another thing.  If condensation occurs then the amount of tank surface above the fuel will be a factor.  You need to have a surface for water to condensate on.  The emptier the tank the more surface you will have for the water.  Now the issue of how fast can the vent let in "fresh" water vapor comes into play again.  If it is really fast then yes I think it would make a difference.  If not you would just end up with the same amount of water over a larger surface area.  Which I have to admit may keep the drops from rolling down into the fuel.  I don't know if that is relevant or not.  So how much of that water really gets into the fuel?  If the tank is not disturbed (sloshed) how much will evaporate back into vapor when the temperature goes up again?  I really wonder if it is not a wash.  Humm I just thought of something, will water condensate onto the surface of fuel itself?  If so then controlling that surface area could make a difference.  If you bring the fuel level up to or even into the vent then you minimize the surface of the fuel.

So what I would want to know is how fast can fresh air get into an average tank to replenish the water vapor already absorbed.  Also how fast does water vapor absorb.  Without that information none of what we have said can be put into context.

So what is the amount of water that ethanol attracts, meaning what percentage of water can E10 fuel hold?  Given that, at what percentage do we start to cause damage?  Because if they do in fact increase the amount of ethanol in fuel then at some point we might exceed that percentage in saturated gas.  

Well enough for tonight!  I think we can all agree that if we keep the wash water out of the fuel fill or vent and we just use our boat enough then it is all academic anyway.

BTW thank you, I am really enjoying  the conversation.  I'm thinking things through and learning things.


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## Brett (Jul 16, 2008)

Been a long time since I played with pressure - temperature - volume....hmmmmm

Lets see here....

Suppose you have 4 gallons of gas in a 6 gallon tank = 2 gallons of fumes/air

Daytime temperature of fuel makes it to 85° F

Night time temperature hits 60° F

Pressure in the vented tank remains the same...1 atmosphere

Need to convert temperatures to degrees kelvin

so 85° F = 302.594° K     60° F = 288.706° K

volume to cubic centimeters

2 gallons = 7571 cc

formula is  (pressure1 x volume1) / temperature1 = (pressure2 x volume2) / temperature2

Pressure is 1 atmosphere before and after

which means  volume1 / temperature1 =  volume2 / temperature2

7571 cc / 302.594° = volume2 / 288.706°

7571 cc x 288.706° / 302.594° = volume2 = 7223.5 cc = 1.91 gallons

So the 2 gallons of air in the tank at 85° F decreases in volume to 1.91 gallons
which means that 0.09 gallons of outside air gets pulled into the tank.
That's only 21 cubic inches of exchange taking place, not a whole lot of water vapor.

Considering that air only holds about 20 cc of water per cubic meter at 75° F, thats about 0.68 ounces

1 cubic meter = 61024 cubic inches

(0.68 ounces / 61024 cubic inches) x 21 cubic inches = 0.0000005 ounces of water enters the tank.

Like I said, most water contamination enters as gravity leakage through the vent and fill... ;D


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## Swamp (Jul 12, 2010)

Glad you did that not me! I'd have screwed up the arithmetic. So depending on how long your vent hose is or should I say how much volume it holds there may not be any exchange of gas(air) at all inside the tank because of temperature related expansion and contraction. The only intrusion would be from Brownian movement, which is not totally insignificant but should still be less that the normal exchange due to temperature.


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## cutrunner (Jun 8, 2010)

All of this math is relevant, but bretts last sentence holds true for 90%of the water in fuel issues i come across. Ie water coming in from sitting on top of the tank because of bad gaskets in the pieholes above the fuel sender. 

Also, theres all this talk of keeping the tank full so that water cant condensate on the roof of the fuel tank.
IMO this is a false ideal.
To fill your tank that full,
1 (which is still about impossible because air will always get trapped in the baffling of the tank) 
2 ( if the boat isnt at an angle where the bow is down during fill up, air will be trapped in the front of the tank)
And 3, if you do somehow fill it completely smack full,
Chances are later that day after the boat sat in the 1000degree heat weve been having, that its vented a gallon of gas out the vent.


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## Swamp (Jul 12, 2010)

You will not get an argument from me about where water comes from most of the time, I agree.

If the trapped air is just that, cut off from the outside, then it will give up the tiny bit of moisture and be done with it.  It can't act as a conduit.  If the tank is angled and has trapped air, same thing.  Yeah, number three would suck though, I'll give you that.  And all of the vents out there including those from manufacturers that have been building long enough to know better are designed to keep that from happening.  Just like all of the professionally installed outboard vents won't let water in because of immersion too.  :  You must have seen some really insane stuff over the years that was done by people and companies that should know better.


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## cutrunner (Jun 8, 2010)

Lol i remember i was moving a 21 parker into the work bay with the fork lift. The guy dropped the boat off in the morning, stating he thinks his gas guage broke. So what did he do? Filled it to the brim lol.
Well i started moving it around 2 (dead of summer), and i guess the moving shook the fuel up and caused it to further expand.
Basically it spewed about 4 gallons of fuel out the vent. What frickin mess.. Had to wash and wax the boat, and re asphault the parking lot of the marina.
It can happen, shouldent, but does.


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## Swamp (Jul 12, 2010)

LOL! Geeze even without the mess, that was awful nice of him to fill it up all the way. Kind of like someone handing you a glass filled to the brim to carry into the next room. I guess that was four gallons you did not have to siphon out so you could replace the sending unit (if that is what was defective).


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## cutrunner (Jun 8, 2010)

Corroded connection lol
What really annoying is when someone has an oil alarm (2 stroke, remote tank), they fill them all the way up the hose to where the fill fitting is inthe boat.
So when i have to take that 5 gallon tank full of oil out of the bilge, all the extra oul in the fill hose drains into the bilge... Making it a pita to change a sender


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## Creek Runner (Sep 1, 2011)

Brett you are way too smart , and I'll let my wife handle math like that she has the MS degree ;D, for now I will keep recommending to my clients what the manufactures tell me to do, and keep charging $100/hour for draining fuel tanks and installing water separators. I do however appreciate the conversation, and next month when I’m in Volvo Tech school I will be bringing up all these points. 

On another note Cut I love when the customer takes delivery of his new boat fills the water tank up with fuel and then wonders why his motor won’t start. Oh and of course it’s the dealers fault!


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## Brett (Jul 16, 2008)

> customer takes delivery of his new boat fills the water tank up with fuel


 

 ;D


Still not as good as the bleary eyed hung over bozo at 4:30 am
who has to call the Haz-Mat crews, because he topped off one of the rod holders,
and filled the bilge with 63 gallons of unleaded.


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