Great News Regarding Too-Tight Gas Caps on Chainsaws

[BrotherBart]

The word from on high, Stihl USA:

"Specifically, the levels of ethanol, aromatics or other additives in some gasoline sold in the United States may distort parts of the fuel cap, which could make caps more difficult to install and/or remove"

From Husqvarna customer service:

"Ethanol in the fuel has caused the fuel tank and gas cap to swell. "

Poulan says the same thing.

 

[Adkjake]

Nice on their part. But how about a fix? Free replacement caps now that it is a known problem. Unlikely

How about make the new saws with aluminum or other metal sleeves and caps? Might cut in to the profit margin
by 50 cents.

Rant over

 

[BrotherBart]

Nice on their part. But how about a fix? Free replacement caps now that it is a known problem. Unlikely

How about make the new saws with aluminum or other metal sleeves and caps? Might cut in to the profit margin
by 50 cents.

Rant over

Actually Sthil is replacing a bunch of'em free of charge. The words came from the recall notice on their website.

 

[Adkjake]

Oh sure, I bought a H'varna

 

[mayhem]

It just doesn't make any sense at all. Ethanol has been in gasoline in widespread use for 30 years now. The fuel tanks don't seem to have a problem swelling up on the saws, so why the ehck are they still making fuel caps out of what is obviously the wrong freaking plastic? All its doing is frustrating their customers and costing the saw manufacturers lost revenue is free replacement caps. I know the fuel cap in my truck is made of plastic and has a gasket, but it doesn't sweel up or anything and its got exposure to E10 24x7, though I guess it never sees liquid exposure, just fumes.

If the oil caps are having the same issues, doesn't that sort of absolve ethanol as the problem here? Same problem but zero ethanol exposure suggests to me that its got to be something else. Or is there 10% ethanol in bar oil too?

 

[Corey]

I'm with you, mayhem - I always have 10% ethanol (or more) in my gas - never once have had trouble with a cap... never had trouble getting the cap off a bottle of vodka, whiskey, or any other spirit either...and those are way more than 10% ethanol!! The cheap stuff even comes in plastic bottles which seem to hold up fine as well.

My oil cap is the one which always gets stuck, so if anything I'd say it is the gunky hydrocarbon dinosaur oil part of the equation which is messing up the caps.

To take the original 'study' at face value is like saying you eat 9 bowls of ice cream (90% gasoline) and one bowl of salad (10% ethanol) ever day - and your waistline expands. So you quit eating food for several days and your waistline shrinks...therefore it must be the salad making you fat.

 

[oldspark]

You guys are funny, there is a problem with the E gas in some cases, have you seen the problems with the plastic gas tanks on Ducati and some other motor cycles, I believe there was a lawsuit. Why they dont change the plastic is a good question, not sure how old the lawsuit is either.

 

[oldspark]

Oh yea I forgot to mention what the problem was with the Ducati tanks, drum roll-it was expanding.

 

[DanCorcoran]

"If the oil caps are having the same issues, doesn’t that sort of absolve ethanol as the problem here? Same problem but zero ethanol exposure suggests to me that its got to be something else. Or is there 10% ethanol in bar oil too?"

What do you mean "bar oil"? I've been putting 87 octane unleaded in the reserve tank, too, so both caps are exposed to ethanol.

 

['bert]

"If the oil caps are having the same issues, doesn’t that sort of absolve ethanol as the problem here? Same problem but zero ethanol exposure suggests to me that its got to be something else. Or is there 10% ethanol in bar oil too?"

What do you mean "bar oil"? I've been putting 87 octane unleaded in the reserve tank, too, so both caps are exposed to ethanol.

"Reserve Tank" Thanks just spit beer all over my keyboard! :lol:

 

[Corey]

There may be problems with the plastic, but it seems quite a stretch to blame ethanol when plenty of cheap plastics hold high concentrations of ethanol with absolutely zero problems. There must be a million liters of vodka setting in plastic bottles right now with no swelling.

This will likely fall on deaf ears, but I would suggest if the issue is related to the gas and not the plastic, the most likely scenario is:

In the 'old days' 87 octane gas was probably more like 88 or 89 because the '87 octane' rating is actually a minimum specification. Plus it contained many big, chunky molecules (technical term) which aren't terribly reactive with plastics/polymers. In the drive for more profit, the refineries learned to better control the product, so 87 octane is really 87 octane, or even 86.55 octane which would round up to 87. In doing this, they crack all the nice heavy molecules into lighter ones which take up more space. Since we buy gas by the volume (gallon), less gas taking up more space is a cheaper product (just like making a cord of tree leaves would generally be easier/cheaper than making a cord of oak wood.

The down side - all small/light molecules are in a range which are reactive with plastics. When ethanol comes along at 107 octane, it allows the refiners to make even crappier gasoline...83, 84, 85 octane...then blend in ethanol's good properties and still have a product which meets the minimum specs.

If ethanol is to 'blame' it's only because the very high octane properties have allowed refiners to make extra crappy gasoline which has the potential to me much more reactive with plastics, but still meet octane spec.

 

[oldspark]

There is enough info out there to convince me there is a problem with the E gas but like you said it is the plastic, they are seeing it in europe now (gas tank problem) with the 5% E gas.