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Discussion Starter · #1 ·
FUEL PROBLEMS

For the past few years, I have had “vapor lock” conditions on some of my trimmer motors and chainsaws. I am using all Echo units. After normal use, (and especially on a hot day) the motor, after sitting a few minutes, will fire and die. If I place the choke at ½ closed, it may run poorly for a little before dying. All this time, the motor is running in a lean condition, bogging down when the throttle is pressed.

I was told that fuels were blended by the seasons now. In the Winter the fuel puts off a lot of fumes and in the Summer there were less fumes (these fumes being called “light fractions”).

The solution was to leave the gas cap off overnight and allow the fuel mix to evaporate.

I am now buying premium fuel, allowing it to vent at least overnight, and mixing my 2 cycle mix at 32-1 rather than 50-1.

All seems to help but on a hot day in the winter at Alpine Texas area (5000’ elevation) I still have some problems. It is not fun when I am high in a tree with a saw that does not want to run.

Anyone else have similar problems.

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Echoman, I don't think what is happening is vapor lock like in carburated engines of long ago. If you were to get out of a vapor locked vehicle, raise the hood and look under the air cleaner, you would see ice build-up on the carb body, that was my interpretation of vapor lock, soon as the ice melted, the carb would work again. The Echos I ran into this problem on, in trees just like you, I tried all kinds of fixes, and it turned out that all I had to do was open the gas cap and it would solve the problem for 15 to 20 minutes, then I'd have to do it again, so I knew it was a fuel vent problem, I can't recall right off what I did to fix it permanetly but try the fuel cap thing next time it happens and see if that solves it and maybe by then I'll remember what I did. These were new Echos 3200/ 3400's etc. and I remember a lot of different guys were bringing 'em to me for this so it wasn't just one crew, it was a saw problem, not operator error.
 

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Discussion Starter · #3 ·
Hey thanks for the heads up. I have not tryed loosening the cap on the fuel tank, but it makes sense. It seems the smaller the motor, the worse the condition. It would be easier to pressurize a small tank than a large one.

Thanks again mowermankevin

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Good post echoman, I am having the same exact problem with ALL my echo equipment. I came close to beating the h*ll out of a BP blower today. Same exact problem as you described. Tried loosening the cap many times to no avail. Then both my hedge clipper when I tried to use them did the same thing. The dealer tells me its the ethanol that is in the fuel causing them nightmares but I don't completely buy that. My BP blower did last about 3 minutes before it started bogging down and sometimes it will do it right off the bat, especially if I leave it sitting in the back of the truck on a 100% day.
 

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Discussion Starter · #5 ·
Good post echoman, I am having the same exact problem with ALL my echo equipment. I came close to beating the h*ll out of a BP blower today. Same exact problem as you described. Tried loosening the cap many times to no avail. Then both my hedge clipper when I tried to use them did the same thing. The dealer tells me its the ethanol that is in the fuel causing them nightmares but I don't completely buy that. My BP blower did last about 3 minutes before it started bogging down and sometimes it will do it right off the bat, especially if I leave it sitting in the back of the truck on a 100% day.
Hi Qcare4u.
Try premium fuel and vent the fuel can at least overnight. A hot day during the winter is the worst. The fuel is apparently blended to put off maximum fumes then. This has helped quite a bit.

Another thing that has worked for me. Although it is inconvenient, I choke it, pull it 6 to 8 times, then it takes 20 to 30 pulls to "de flood", then it will run ok. Pain in the a__ but makes it work.

ETHANOL (alcohol) __________ AVOID AVOID AVOID ________ Find some fuel distributor that has NO ALCHOHOL in the fuel. If you get a little bit of moisture in your gas tank (in the presence of gasahol) the alcohol will separate with the water. The water/alcohol mix will burn but will have no lubrication with it. The piston and cylinder will be destroyed on the intake side.

Thanks
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Echoman, I find it hard to believe that alcohol is the problem, I didn't say anything about venting overnight cause the volatile organic compounds evaporate with no closed cap,(EPA doesn't like that), so if I'm reading what your saying, the machinery works better after the fuel has set overnight with the caps off? Doesn't make sense to me, the vapor that is visible coming out of the jug is the most powerful part of the mix. I'm confused, I don't get how what is left over in the morning is better than what went in at the pump.Please educate us. Keep us posted, it's so da** hot here now, I went out to P and it was just Texas, told everybody that called,"Go to house, it's too da** hot" C'ya K
 

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Discussion Starter · #7 ·
The comment about the alcohol and the "blended fuels" are two and totally separate issues.

Gasahol destroys 2 cycle engines frequently. Avoid it. Ask any 2 cycle mechanic with experience.

Obviously I am not going to convince you of the "blended fuels" giving vapor lock type of symptoms. I can only say it works for me.

Did not mean to come off as a prof. Sorry
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Can I give my two cents worth of Vapor Lock as I perceive it? It's not uncommon during the summer months for many contractors to report fuel around the carb and tank when a machine has stood in the heat unused for a few hours.
As I see it most tanks have a vent to allow air in as the fuel is used, this is a one-way valve so as not to have fuel escape from the valve. When left standing the fuel vapor will expand in the heat, often causing the tank to have a 'bulged' look. When you undo the tank cap you can hear a rush of air/vapor. I've seen this pressure build up to the extent it can force fuel past the needle valve and flood the engine making for difficult starting.
I advise using a richer mix of oil/petrol during the summer months if the weather is exceptionally hot, ie from 50 to 1 to 40 to one. The slight increase in oil content will help maintain compression and aid heat/friction without excessive smoking from the exhaust.

As said in a previous post, leaving the tank cap loose to vent can, in most cases, help eliminate this problem

atb Phil :usflag:
 

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Discussion Starter · #9 ·
Hi Phil,

I go past the limits of my knowledge much too often. Thanks for the post.

The problem on my equipment is similar but different. After running the 2 cycle motor hard, then immediately putting fuel in it, starting, then the motor will be most difficult to run. The motor is running lean. By forcing it to run by moving the choke in and out and, at the same time, moving the throttle much the condition smooths and the unit runs fine. This takes an honest 2 minutes (sounds short on paper, but is testing on a job site).

Granted some of my echo's have 1000hrs+, but some are new. This happens on old and new.
 

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Hi Phil,

I go past the limits of my knowledge much too often.
Hey, I do that every day :dizzy: must be an age thing with me.
You say it's running lean, have you got an adjustable carb? maybe just a tweak more fuel?. When I tune a two stroke engine I do my best to balance the carb so the engine (when warm) will start in any throttle position. Are you in one of the 'heatwave' states? if it is extra hot do try a tad more oil in your mix, it really can help to keep the engine temperature down to an acceptable level.

Here's a pic of a Stihl I had in on Saturday, they guy figured he could run it lean on the oil :hammerhead:



Over here the cylinder/barrel is half the cost of a new machine.
Another one bits the dust
atb Phil :)
 

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Discussion Starter · #11 ·
Scored all the way around.

Story === Local businessman (construction) in town of 500. Me, "Sir, the engine was run without oil because it is scored all the way around." He, "No, the mix had oil. All I did was put carburetor cleaner (berryman) in it."

A little just scores the intake, but a lot is the same as raw gas.

The oil scare in the middle 80's was the demise of many a 2 cycle. Three oil companies in my area put alcohol in the fuel. I sold a lot of echo saws that year.

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FUEL PROBLEMS

For the past few years, I have had “vapor lock” conditions on some of my trimmer motors and chainsaws. I am using all Echo units. After normal use, (and especially on a hot day) the motor, after sitting a few minutes, will fire and die. If I place the choke at ½ closed, it may run poorly for a little before dying. All this time, the motor is running in a lean condition, bogging down when the throttle is pressed.

I was told that fuels were blended by the seasons now. In the Winter the fuel puts off a lot of fumes and in the Summer there were less fumes (these fumes being called “light fractions”).

The solution was to leave the gas cap off overnight and allow the fuel mix to evaporate.

I am now buying premium fuel, allowing it to vent at least overnight, and mixing my 2 cycle mix at 32-1 rather than 50-1.

All seems to help but on a hot day in the winter at Alpine Texas area (5000’ elevation) I still have some problems. It is not fun when I am high in a tree with a saw that does not want to run.

Anyone else have similar problems.

de
I don't have a lot of 2 cycle experience but I have worked as a mechanic before. The U.S. Army taught me to be a diesel mechanic,I've worked at a Ford tractor dealership and a Cheverolet dealership, as well have taken courses from a local college in mechanics and have a degree in auto body. There is a lot of things I don't know but I understood vaporlock is caused by the gasoline turning into vapor in the fuel supply line causing a bubble so fuel refuses to flow. The solution back when I was a mechanic was to insulate the fuel line especially where it ran close to the hot engine. Insulation covered by aluminum foil was the cure. Don't know if that will help but it is MHO. By the way I'm suffering similar problems with Stihl and Robin so don't feel left out, I think it's the heat so anything you can do to lower that should help. My 2 cents.
 

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Discussion Starter · #13 ·
I don't have a lot of 2 cycle experience but I have worked as a mechanic before. The U.S. Army taught me to be a diesel mechanic,I've worked at a Ford tractor dealership and a Cheverolet dealership, as well have taken courses from a local college in mechanics and have a degree in auto body. There is a lot of things I don't know but I understood vaporlock is caused by the gasoline turning into vapor in the fuel supply line causing a bubble so fuel refuses to flow. The solution back when I was a mechanic was to insulate the fuel line especially where it ran close to the hot engine. Insulation covered by aluminum foil was the cure. Don't know if that will help but it is MHO. By the way I'm suffering similar problems with Stihl and Robin so don't feel left out, I think it's the heat so anything you can do to lower that should help. My 2 cents.
Thanks,

The comments are very constructive.

On the chainsaws, the fuel lines are internal. I will try wrapping one of them to compare with the others. On the trimmer motors, the lines are exposed. I will wrap one of them also, but, I doubt that it will help. WILL TRY THOUGH!

When I originally posted, I should have posted "Vaporlock TYPE conditions." I actually believe something else is going on.

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I have the same problems with the gas caps I bought some vented gas caps and they seem to help quite a bit. my dealer said it is the alcohol in the gas. Said it is killing more carbs than he has ever seen. He talk to shindiawa and Kohl and they told him to recommend to all lawn guys they keep caps on all there gas cans to prevent extra moisture from being drawn in from the alcohol.
 

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Discussion Starter · #15 ·
I agree that alcohol will kill 2 cycle engines. We solved the problem by calling the fuel distributors and asked "Do you have fuels with alcohol?".

When moisture mixes with GASAHOL (FUEL WITH ALCOHOL MIXED WITH IT), the moisture takes the alcohol from the gas mix. This mix of "alcohol and water" is heavier than gas and oil. The fuel system picks up the lowest part of the gas tank. The fuel system gets the ALCOHOL AND WATER rather than the gas and oil.

There is no lubrication. The engine scores on the carburetor side.

You are lucky if it kills carbs rather than an engine.

Echo, at one time, would put gas hoses that would melt in the presence of alcohol. This saved the motor.

I have been gone way too long to know if they defend against alcohol with the same fuel hoses now.

Good luck

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digging up this old thread because today we had the same problem. Here in Florida it was over 95 and hot as heck. last house of day, everything is Echo and on an open trailer in the blaring sun...and nothing wanted to run. not the edger, trimmers or blower. All had very empty fuel primer bulbs and was hard to get the fuel to start flowing and get equipment running....could tell when it would try to sputter to life, there was minimal fuel flowing thru return line. Could see lots of air bubbles in the clear fuel return lines. It took lots of priming with the bulbs, choking, and patience but after several minutes...got everything running. never experienced this before so i came here to see if other people had experienced this.
 

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Ah no, no, no :nono:

First you need to monitor yourself, in this heat the chainsaw might not be the only thing overheating,
no equipment will give you more trouble than when the operator is feeling a bit hot in the head.
Then you need to change your system, you can't just shut down a hot engine dump fuel in the tank and go,
that won't work at all, for one it's dangerous but it's just not the way to do things.

You have to do a little bit of planning, before starting the engine, all of the work you are going to do with that one tank of fuel,
that's assuming you intend to run through at the very least the whole tank.

If you do not intend to run through the whole tank, also visually plan out everything that needs to be done with the tool.

Once you have your plan set, start the engine and get to work, now don't stop working until plan completion.
Granted, might not work so good up in a tree.
Once that engine is running don't cut it off!
Let it idle if you have to, but keep working.

Once it runs out of fuel, time for a break.
You need to take at least 10 or 15 minutes in the shade, drink water, cool yourself down.
Then you can either grab another chainsaw that's all fueled up and ready to go, or sit down and
prepare to change the chain, refill the bar oil, and fill the fuel on the one that you just used.
Try and do this in the shade, like under a tree, and yes you can do the maintenance as part of cooling yourself down.

Then, take another 5-10 minutes, let the saw cool off, all in all we're looking at a 15-20 minute break here but it's not
set in concrete, don't let it take forever but it takes how long it takes, the saw won't run right otherwise.
Don't forget to monitor yourself in this heat.

If, after all of that the saw still won't run:
Plan B - Start carrying two saws to the job, and switch off one, then the other.
Still do the maintenance, that way you always have one ready later.

Gtg.
 

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I think you are going to see more of this as the EPA is making everyone go to non-vented fuel systems or one-way only systems (air in but not out). As pressure builds up in the tank you are going to have problems and even more so on hot day. I hear about this same problem every single year, year in and year out. I see a day when you will have charcoal canisters one every thing not just cars. I know some people that will only fill their trimmers and saws to half a tank in hopes that will give more time until it acts up. Thank you, EPA.
 
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