Gas supply naivete?

[glenintenn]

Over the last several months I've been trying to root cause the problems with three chainsaws:
- one is a cheapy Homelite 3816, 42cc plastic special. Even though cheap, it's been a surprisingly reliable saw
- an MS170
- an MS180C

All three stopped working over the winter. One thing I was doing last season was using ethanol free 93 grade gas and then trying to run each saw out of gas by emptying the tank and then letting the machine idle until it stalled before putting it away. Spring '24 tried to use the saws and nothing. Had to use an old 14" Ryobi which I had in storage. Finally got back to the saws last week and started with the homelite. I'd just put a new Amazon-special carb on it last year to get it back to working order. I thought maybe I had an air leak in the hoses so I replaced all the fuel lines and then tried to get it running again... it would start and run for a bit. After a lot of fooling with the H, L and idle jets I could never get it to balance out where it would idle but still have low end power. Finally got frustrated and got another Amazon special carb because I have stuff to do other than play with chainsaw carbs. Put the new one on and it fired right up ... idles fine, low end power is back to what it should be.

So I took apart the old Amazon special carb. Lo and behold ... it had several tell-tale signs of fuel turned to shellac/varnish in various jets and the screen over the main jet was opaque when held up to a light. There was also rather hard build up on the diaphragm side in some of the cupped recesses of the carb. I assumed this was from the remnants of gas in the carb when I ran it dry last fall.

All that to ask: is ethanol-free gas, really ethanol free? why would there be varnish in gas which has dried up if it's ethanol free?

 

[Haywire Haywood]

Being ethanol free doesn't mean that it doesn't go bad and varnish up. Being ethanol free means that doesn't attract water and separate. You're doing good by running them dry, but still use stabil. Good gas will still go bad and you can't get every little drop out of the carb. I run mine dry with stabil in the fuel and they crank every time after sitting for many months.

 

[coffeebrk]

Are you getting the ethanol free gas from a dedicated pump or a multi pump?

 

[glenintenn]

the pumps I use have a separate hose/handle for the ethanol free gas. the pump is split -- on the left is the ethanol free hose/handle. on the right is a hose/handle for the ethanol gas

 

[coffeebrk]

I only buy 1 gallon of rec gas at a time. After letting it settle for a while I take out a sample from the bottom of the can. That sample goes into a glass jar to check for water.
This process also let's me see the clarity of the gas. Having between 10-15 saws at any given time some may not be used for a year or two while some get frequent use.

 

[glenintenn]

yeah. I use about 1 to 1-1/2 gallons of mixed gas per season and in the spring of this year, I dumped the previous fall's mixed gas and mixed a new batch out of recently purchased 93 ethanol free.

 

[sean donato]

The simple solution is to go and get a gallon of canned fuel, last 2-3 years in the saw. Been doing that for years with equipment I seldomly use.

 

[Haywire Haywood]

Or a combination of the above... If you don't want to spend the extra cash on canned fuel for regular use, buy a quart can of it and when you're ready to put it away for the winter, run it dry, restart it on canned gas to flush the carb, then run it dry again.

 

[ray benson]

Or a combination of the above... If you don't want to spend the extra cash on canned fuel for regular use, buy a quart can of it and when you're ready to put it away for the winter, run it dry, restart it on canned gas to flush the carb, then run it dry again.

That is what I have been doing for about the last 5 years.

 

[epo]

All three stopped working over the winter. One thing I was doing last season was using ethanol free 93 grade gas and then trying to run each saw out of gas by emptying the tank and then letting the machine idle until it stalled before putting it away.

In addition to other good advice here, I think you can still improve this procedure by trying to start the engine with the choke plate closed and at a fast idle (cold start position of the master control lever on Stihls) after the engine stalls in the way you described.

 

[glenintenn]

Is canned gas subject to the 90 day rule once the can is opened?

After 90 days, gas is no longer Scottish... ?

 

[oldbuzzard]

I own and work on LOTS of saws. I ONLY put store bought premix gas in them, VP if I can get it. I routinely leave saws, weedwhackers, etc over the winter without draining them and I don’t have any problems. The premix stuff is advertised as having a two year life.

 

[sean donato]

Or a combination of the above... If you don't want to spend the extra cash on canned fuel for regular use, buy a quart can of it and when you're ready to put it away for the winter, run it dry, restart it on canned gas to flush the carb, then run it dry again.

More or less what I do, can't afford canned gas with the amount of fuel I go through during the year. Just use it for storage. A gallon goes a long way purging regular gas out if the carb.

 

[sean donato]

Is canned gas subject to the 90 day rule once the can is opened?

After 90 days, gas is no longer Scottish... ?

View attachment 1201235

2-3 years after the original can is opened. Storage conditions/ temps will affect it when it's in equipment, but generally speaking a year is no issue and I've had no issues starting the edger after 2 years purged with canned fuel. (I drain the tanks for long term storage.)

 

[David Ellis]

Over the last several months I've been trying to root cause the problems with three chainsaws:
- one is a cheapy Homelite 3816, 42cc plastic special. Even though cheap, it's been a surprisingly reliable saw
- an MS170
- an MS180C

All three stopped working over the winter. One thing I was doing last season was using ethanol free 93 grade gas and then trying to run each saw out of gas by emptying the tank and then letting the machine idle until it stalled before putting it away. Spring '24 tried to use the saws and nothing. Had to use an old 14" Ryobi which I had in storage. Finally got back to the saws last week and started with the homelite. I'd just put a new Amazon-special carb on it last year to get it back to working order. I thought maybe I had an air leak in the hoses so I replaced all the fuel lines and then tried to get it running again... it would start and run for a bit. After a lot of fooling with the H, L and idle jets I could never get it to balance out where it would idle but still have low end power. Finally got frustrated and got another Amazon special carb because I have stuff to do other than play with chainsaw carbs. Put the new one on and it fired right up ... idles fine, low end power is back to what it should be.

So I took apart the old Amazon special carb. Lo and behold ... it had several tell-tale signs of fuel turned to shellac/varnish in various jets and the screen over the main jet was opaque when held up to a light. There was also rather hard build up on the diaphragm side in some of the cupped recesses of the carb. I assumed this was from the remnants of gas in the carb when I ran it dry last fall.

All that to ask: is ethanol-free gas, really ethanol free? why would there be varnish in gas which has dried up if it's ethanol free?

I kinda think you are doing everything about right. Probably adding some sta-bil will help. I have used ethanol free for perhaps 30 years and have very few problems and leave most of my carburetors wet. But, I still have a few problems. I think I have a dozen carburetors (mostly small engine) and have to clean or rebuild a carburetor every 2-3 years.

With your chainsaws, they might "prefer" to be put away wet for the season when finished.

And a direct answer to your question. Gasoline still has additives but I don't ever remember seeing the additives when gas (not mixed) dries. I suspect the film is your 2 stroke oil which should indeed form a coating when the solvent dissipates. The hope is the film would re-dissolve in the gas solvent during the next use. For me, I don't know if my Klotz R50 2 stroke oil preference does anything magical during storage, but it sure smells nice when burning through the engines.

 

[Sidecarflip]

Or a combination of the above... If you don't want to spend the extra cash on canned fuel for regular use, buy a quart can of it and when you're ready to put it away for the winter, run it dry, restart it on canned gas to flush the carb, then run it dry again.

Really not necessary to run them dry with canned gas in them. Canned gas (I use Echo Red Armor 50-1) stays viable over the winter no issue, at least for me and I'm an occasional user as well.

Only thing that gets 'corn squeezed gas' is my wife's zero turn and our small inverter genny for the RV but both get a dose of Blue Marine Stabil in them religiously. Of course the vehicles are on corn squeezed gas as well but it don't sit long in them. Blue Marine Stabil (not the worthless red stinky stuff) works and keeps phase separation under control. It's not cheap but it works. Everything else around here is diesel powered and all my diesel powered equipment also gets a dose of Biocide as I've experienced the dreaded algae in diesel fuel and it's not a cheap date to remedy. Finally, I only use Powerservice biocide. No matter what the other 'elixers' claim, if there isn't an MSDS label attached to them, they have no biocide in them. The PS biocide isn't a cheap date either but it don't take a lot to protect against algae growth in standing diesel fuel. My 500 gallon bulk diesel tank gets treated as well.

 

[Mad Professor]

If I'm going to run a lot of gas I'll use non-corn premium in mix, and use it all up or dump it into one of the farm tractors if it gets a few months old.

Otherwise I still use 100LL AV gas and that gives me zero problems, mix stores about indefinitely if put in metal Coleman fuel cans. I'm old enough I'm not worried about a small amount of lead getting into my system but am careful with it, wear gloves when working with the liquid or the insides of the equipment that has run it.

Never had a problem with equipment left in summer and started next time in the spring either.

 

[Sidecarflip]

My tractors are all diesel powered here and large because I farm. Pickup truck is as well. I worry little about the diesel even though it's ULSD, just add the recommended amount of Biocide when I fill them up plus it's in my bulk tank. One nice thing about biocide is, you cannot 'overdose' it.

Learned my algae lesson the hard way years ago when B20 was the rage. B20 is notorious for growing algae. Sure it smells nice (like French Fries cooking), but far as using it for tractor and pickup fuel, no way. My 'experience' cost me over a grand in replacement parts and I did all the grunt work myself. Glad it was confined to my diesel pickup truck. Had to remove and drain and flush the fuel tanks, replace the tank diverter valve (I have 2 fuel tanks on it), replace the injectors as well as the main fuel bowl. I did add a Racor fuel polishing units to the incoming fuel line between the diverter valve and the supply line and I've added Racor fuel polishing units to both my tractors as well as my diesel powered lawnmower with Racor 2 micron filters on the diesel powered lawnmower and 10 micron filters on the tractors. Nice thing about the Racor fuel polishing units is they remove 99% of any solid contaminants as well as 100% of any algae that may be present in the fuel supply and the Racor units all have a spin on replaceable filter plus they come with a drainable clear bowl on the bottom so you can readily see what the filter has stripped out of the fuel and drain it off.

Since I've installed the Racor units, I have not had to change any of the spin on fuel filters on the tractors or on the pickup truck either. They aren't a cheap date but well worth the cost. All large ships as well as diesel powered pleasure boats as well as big trucks that are diesel powered either come equipped with Racor units or offer them as an option. Easy to install as well, just the initial cost is kind of high.

 

[Haywire Haywood]

Otherwise I still use 100LL AV gas.

I used to go to the local airport and get 100LL when I was cutting on the regular, but a bucees has opened up here in the last few years and they have several pumps dedicated to zero ethanol. I used to have to pick a tail number off a private airplane to punch into the airport pump. Couldn't buy it unless a tail number was punched in. Of course I swiped my CC at the pump. My purchases probably showed up on some fellas airplane records. Haha

 

[bwalker]

I used to go to the local airport and get 100LL when I was cutting on the regular, but a bucees has opened up here in the last few years and they have several pumps dedicated to zero ethanol. I used to have to pick a tail number off a private airplane to punch into the airport pump. Couldn't buy it unless a tail number was punched in. Of course I swiped my CC at the pump. My purchases probably showed up on some fellas airplane records. Haha

Oddly enough at the small local air port local to me I drove my truck right out to the terminal and filled up as needed. The last time I did this was several years ago. I no longer have a machine that needs avgas and I absolutely will not run it in outdoor power equipment.