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av8tor1977 01-13-2013 12:00 PM

Strange fuel problems...
 
Numerous times the experts have weighed in saying that there are no issues with todays fuel with regards to fuel lines and carb diagrams. I have mentioned myself though, that I certainly have had problems, and I often repair yard equipment and fully 90% of the problems with them that I find are rotten fuel lines and/or carb diaphragms gone stiff.

I recently needed to get my 25 year old chainsaw going quickly to help a friend that needed it. It had not been run in 5 years and in the 25 years I have owned it I have never once changed the fuel lines nor rebuilt the carb. (I swear that is true, and it has cut literally tons of wood.) I thought "there is virtually no way the fuel lines and carb are going to be ok, but I don't have time to service them so I'll just try to start it." There was some congealed oil/gas in the tank, so I poured some acetone in the tank, and let it soak while I checked/cleaned the spark plug. I then sloshed the acetone around, poured it out, and fueled the saw up. To my utter and complete amazement, it started on the second pull and ran perfectly!

I had the same thing happen with another chainsaw just the other day. A different saw I have hadn't been run in several years. On this one I needed to prime it with a squirt of fuel into the cylinder, but then it started up and ran on the first pull, and ran perfectly. I cut a bunch of wood with it with no problems.

Now on the other hand, I have had airplanes give me fuel system problems, sometimes in as little as 6 weeks of non-use. My brother had a plane with a Ryobi 31cc engine on it. He came to visit and we tuned and flew the plane. 6 weeks later he came back and it wouldn't run right. I fought with it for a bit, because I couldn't believe it could have carb problems after only 6 weeks of sitting. But finally I gave in and pulled the engine and carb, and sure enough, the diaphragm was "stiff as a board." I had a similar incident with my own Giles 30cc and other planes. It is really embarrassing for the local engine "guru" (ME), to show up at the field and have engine problems!! It was so bad that I finally started de-fueling all my planes after flying, and running them briefly on Coleman fuel with Sta-Bil and 20:1 Pennzoil before storing them. That solved all fuel system problems with all my planes. The neoprene fuel line in my fueling jug gets completely stiff on the part that is not submerged in gas. I have tried Tygothane, Neoprene, etc., but they all seem to be affected by the fuel to varying degrees.

So, either the materials in the fuel systems in those old saws was much better, or the fuel has changed and DOES affect carbs and fuel lines.

NOTE: I personally do not use, nor endorse, flying with Coleman fuel in any engine. (Yes, I know, some claim to use it with no problems. Not me.)

AV8TOR

Nosedragger 01-13-2013 01:18 PM

RE: Strange fuel problems...
 
Coleman is 55 octane , not good for a high performance two stroke.

The issue I have seen with oxygenated fuel is people let them sit without running dry. The problem is people not adapting to new fuel formulations which boils down to maitnenance.
If you have problems with the new fuel its not the fuel that is the issue it is your maintence and operation.

I maintain a fleet of lawn tool equipement and see no issues with the formulation of the new fuel. These engines run everyday or at least several times a week.Letting them sit for weeks at a time causes the problems.

pe reivers 01-13-2013 01:39 PM

RE: Strange fuel problems...
 
we have 8 to 10% ethanol in our fuel. Running carbs dry will cause the diaphragms to harden. I have no problems at all if I just put the plane away without running the carb dry.
OTOH, when I tested a Chinese import engine, the carb went bad in a few runs. Certainly old walbro stock diaphragms. Replaced them and saw no more problems.
I do believe, that worldwide the fuel can, and will have more influence on the carb parts than the fuel companies care to admit. I am happy to live in Europe, where good ingredient limits are installed, and low quality fuel is no longer available. Don't blame the 10% ethanol. Your carb is up to that task.

rangerfredbob 01-13-2013 07:42 PM

RE: Strange fuel problems...
 
I have similar experience with gunked up parts and some engines sitting for long periods of time without use working without issue... I have a little Homelite XL saw (the little 25 or 30cc guys with 9" or so bars) that I got at a garage sale for $5 probably 7 years ago, it ran good when I got it but the chain was sharpened unevenly so it would only cut about 2" before getting stuck... Anyway, that saw sat unused for ~5 years, pulled it out and it ran like a champ still, almost always starts within a few pulls (except last night, was stubborn but was 25* outside...). I have an old Homelite 540 that I got cheap, wouldn't run, had a dried out regulator/metering diaphragm so I stole one out of a running weedeater, that sat for 5 years without running also, started it up a while ago and it runs like a top with that same diaphragm...

I've also been the "gas guru" with the broken plane from a failed diaphragm at the field...

I've had best luck keeping fuel in 2 strokes, and running 4 strokes dry, but I usually forget and leave everything with fuel in it...

1QwkSport2.5r 01-13-2013 08:15 PM

RE: Strange fuel problems...
 
I have started a regimen with my small engine gasoline I buy; I use the blue marine Sta-Bil at 1oz/gallon which helps with phase separation, and I use 1oz per gallon seafoam motor tune. I do this to my big 5gal can, from this I will fill a 1-gallon can for my weedeater and ice auger and add oil for 20:1 ratio. I leave fuel in all of my engines when not in use and have had zero diaphragm or varnish problems. Ethanol blended fuels tend to varnish easier it seems, the seafoam keeps that from happening, and the sta-Bil keeps the ethanol from settling out from the gasoline if saturated with moisture.

I quit using 92/93 octane gas in my small engines as well. The muffler on my snowblower would glow red on high test gas. It doesn't do it on regular 87 octane. Rumor had it that the slow burning gas is still burning when getting blown out the exhaust valve and the muffler glows because of that. I just figured small engines run better on non-ethanol gas... At least for me, they don't.


Nosedragger 01-14-2013 05:48 PM

RE: Strange fuel problems...
 
Quote:

ORIGINAL: pe reivers

we have 8 to 10% ethanol in our fuel. Running carbs dry will cause the diaphragms to harden. I have no problems at all if I just put the plane away without running the carb dry.
OTOH, when I tested a Chinese import engine, the carb went bad in a few runs. Certainly old walbro stock diaphragms. Replaced them and saw no more problems.
I do believe, that worldwide the fuel can, and will have more influence on the carb parts than the fuel companies care to admit. I am happy to live in Europe, where good ingredient limits are installed, and low quality fuel is no longer available. Don't blame the 10% ethanol. Your carb is up to that task.

you have to run dry to get the alcohol out of the carb.no alcohol no diaphragm dry out.
the carb can handle the alcohol but it can not handle the moisture the alcohol absorbs and deposits inside it.

seafoam is crap, it is naptha aka coleman fuel 55 octane bilge fluid waiting to detonate your engine apart (if it a high performance two stroke)

Water damage is a bigger issue with alcohol bearing gasoline than diaphragm drying.




Quote:

I quit using 92/93 octane gas in my small engines as well. The muffler on my snowblower would glow red on high test gas. It doesn't do it on regular 87 octane. Rumor had it that the slow burning gas is still burning when getting blown out the exhaust valve and the muffler glows because of that. I just figured small engines run better on non-ethanol gas... At least for me, they don't.
rumor its just a rumor

rcairboater 01-14-2013 07:27 PM

RE: Strange fuel problems...
 
Quote:

ORIGINAL: av8tor1977

Numerous times the experts have weighed in saying that there are no issues with todays fuel with regards to fuel lines and carb diagrams. I have mentioned myself though, that I certainly have had problems, and I often repair yard equipment and fully 90% of the problems with them that I find are rotten fuel lines and/or carb diaphragms gone stiff.

I recently needed to get my 25 year old chainsaw going quickly to help a friend that needed it. It had not been run in 5 years and in the 25 years I have owned it I have never once changed the fuel lines nor rebuilt the carb. (I swear that is true, and it has cut literally tons of wood.) I thought ''there is virtually no way the fuel lines and carb are going to be ok, but I don't have time to service them so I'll just try to start it.'' There was some congealed oil/gas in the tank, so I poured some acetone in the tank, and let it soak while I checked/cleaned the spark plug. I then sloshed the acetone around, poured it out, and fueled the saw up. To my utter and complete amazement, it started on the second pull and ran perfectly!

I had the same thing happen with another chainsaw just the other day. A different saw I have hadn't been run in several years. On this one I needed to prime it with a squirt of fuel into the cylinder, but then it started up and ran on the first pull, and ran perfectly. I cut a bunch of wood with it with no problems.

Now on the other hand, I have had airplanes give me fuel system problems, sometimes in as little as 6 weeks of non-use. My brother had a plane with a Ryobi 31cc engine on it. He came to visit and we tuned and flew the plane. 6 weeks later he came back and it wouldn't run right. I fought with it for a bit, because I couldn't believe it could have carb problems after only 6 weeks of sitting. But finally I gave in and pulled the engine and carb, and sure enough, the diaphragm was ''stiff as a board.'' I had a similar incident with my own Giles 30cc and other planes. It is really embarrassing for the local engine ''guru'' (ME), to show up at the field and have engine problems!! It was so bad that I finally started de-fueling all my planes after flying, and running them briefly on Coleman fuel with Sta-Bil and 20:1 Pennzoil before storing them. That solved all fuel system problems with all my planes. The neoprene fuel line in my fueling jug gets completely stiff on the part that is not submerged in gas. I have tried Tygothane, Neoprene, etc., but they all seem to be affected by the fuel to varying degrees.

So, either the materials in the fuel systems in those old saws was much better, or the fuel has changed and DOES affect carbs and fuel lines.

NOTE: I personally do not use, nor endorse, flying with Coleman fuel in any engine. (Yes, I know, some claim to use it with no problems. Not me.)

AV8TOR

Hi Robert! Have a question for you. Being in Ohio, after the season is over which is around November, and doesn't pick up again until April how do you recommend I store the engine for the winter months? What do I need to do with the engine?

Also, I want to thank you for a amazing engine you did for me. If anyone is looking for a conversion engine Robert is your man. I received my Stihl conversion about a week ago. Robert dismantled the engine to check the bearings, cylinder, seals etc. The engine was completely cleaned and new seals were added. Additionally Robert made some carb mods and machined me a polished hub and turned down the flywheel and added paint as well.
My muffler was painted and a exhaust pipe outlet was added as well. I highly recommend Robert for any of your engine needs. Robert has excellent communications and does the job correctly. This is my third engine from Robert and this is where I will continue to do business with in the future.

Thanks again Robert for another awesome engine.

-Gary

1QwkSport2.5r 01-14-2013 07:29 PM

RE: Strange fuel problems...
 
It's funny that I havent had a single carb problem since I started this regimen. To each his own I guess.


av8tor1977 01-15-2013 03:59 AM

RE: Strange fuel problems...
 
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Quote:

ORIGINAL: rcairboater

Quote:

ORIGINAL: av8tor1977

Numerous times the experts have weighed in saying that there are no issues with todays fuel with regards to fuel lines and carb diagrams. I have mentioned myself though, that I certainly have had problems, and I often repair yard equipment and fully 90% of the problems with them that I find are rotten fuel lines and/or carb diaphragms gone stiff.

I recently needed to get my 25 year old chainsaw going quickly to help a friend that needed it. It had not been run in 5 years and in the 25 years I have owned it I have never once changed the fuel lines nor rebuilt the carb. (I swear that is true, and it has cut literally tons of wood.) I thought ''there is virtually no way the fuel lines and carb are going to be ok, but I don't have time to service them so I'll just try to start it.'' There was some congealed oil/gas in the tank, so I poured some acetone in the tank, and let it soak while I checked/cleaned the spark plug. I then sloshed the acetone around, poured it out, and fueled the saw up. To my utter and complete amazement, it started on the second pull and ran perfectly!

I had the same thing happen with another chainsaw just the other day. A different saw I have hadn't been run in several years. On this one I needed to prime it with a squirt of fuel into the cylinder, but then it started up and ran on the first pull, and ran perfectly. I cut a bunch of wood with it with no problems.

Now on the other hand, I have had airplanes give me fuel system problems, sometimes in as little as 6 weeks of non-use. My brother had a plane with a Ryobi 31cc engine on it. He came to visit and we tuned and flew the plane. 6 weeks later he came back and it wouldn't run right. I fought with it for a bit, because I couldn't believe it could have carb problems after only 6 weeks of sitting. But finally I gave in and pulled the engine and carb, and sure enough, the diaphragm was ''stiff as a board.'' I had a similar incident with my own Giles 30cc and other planes. It is really embarrassing for the local engine ''guru'' (ME), to show up at the field and have engine problems!! It was so bad that I finally started de-fueling all my planes after flying, and running them briefly on Coleman fuel with Sta-Bil and 20:1 Pennzoil before storing them. That solved all fuel system problems with all my planes. The neoprene fuel line in my fueling jug gets completely stiff on the part that is not submerged in gas. I have tried Tygothane, Neoprene, etc., but they all seem to be affected by the fuel to varying degrees.

So, either the materials in the fuel systems in those old saws was much better, or the fuel has changed and DOES affect carbs and fuel lines.

NOTE: I personally do not use, nor endorse, flying with Coleman fuel in any engine. (Yes, I know, some claim to use it with no problems. Not me.)

AV8TOR

Hi Robert! Have a question for you. Being in Ohio, after the season is over which is around November, and doesn't pick up again until April how do you recommend I store the engine for the winter months? What do I need to do with the engine?

Also, I want to thank you for a amazing engine you did for me. If anyone is looking for a conversion engine Robert is your man. I received my Stihl conversion about a week ago. Robert dismantled the engine to check the bearings, cylinder, seals etc. The engine was completely cleaned and new seals were added. Additionally Robert made some carb mods and machined me a polished hub and turned down the flywheel and added paint as well.
My muffler was painted and a exhaust pipe outlet was added as well. I highly recommend Robert for any of your engine needs. Robert has excellent communications and does the job correctly. This is my third engine from Robert and this is where I will continue to do business with in the future.

Thanks again Robert for another awesome engine.

-Gary

Hi Gary and thanks,

If you haven't run the engine since I sent it to you, then you are ok until you want to run it in April because I already ran it with my "storage fuel", which is Coleman fuel with Sta-Bil and 20:1 Pennzoil, on the last run before I sent it to you, and then I capped the fuel tubes. If you have run it since you received it, then I would just leave the fuel in the carb, cap the inlet and primer tubes, and go ahead and store it. The fuel that is in it should keep the diaphragms wet and pliable, (hopefully), especially if it is with my special "storage fuel."

Thanks again,
AV8TOR

pe reivers 01-15-2013 06:36 AM

RE: Strange fuel problems...
 
Cleaning Naphtha is an excellent "after run" fuel for extended storage both gas and glow.
The one available here has a boil trajectory of 100_140°C, octane number unknown. I am not too familiar with Coleman specs though. I know octane number is 55, which seems largely identical.
I used the Naphtha oil mix mainly for glow engine storage. Run a small amount of 50/50 Naphtha/ATF mix in the engine to get all methanol and nitro traces out.


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