Experiences with pump gas vs premix?

[Robert P]

Do any of you use storebought premix? I grabbed some when I recently bought a new saw out of curiosity - saw runs fine on it. You can get bad gas at a gas station but any sense as to whether there's any consistent difference assuming using a decent oil?

 

[BlackSmith]

I just use the 93 proof non ethanol. No problems out of the ordinary.

 

[SkwerI]

If you're only using small quantities it is fine. I burn a couple gallons of mix per week so I'm not paying the price for premix. If a gallon of mix will last you a few months then by all means use the premix stuff and save yourself the headaches of old fuel.

 

[biggun]

I was working for a guy earlier in the week. Ms200t was a working fine and I needed a refil so in went the aspen. I usually mix pump fuel.

Today it ran like a dog. Loads of power in the cut but I kept having to rev it to stop it stalling. I needed a refil. Used my own mix and grabbed a tuning driver to up the idle. It ran perfectly. New fuel, no adjustment...

Any ideas?

 

[Raj]

I'll top up my saws with synthetic fuel when I put them away. Used to run only run synthetic in the climbing saws, thinking that would solve my bogging issue, turned out it was an accelerator pump in the carb. Back to mix pump gas.

 

[pete mctree]

I was working for a guy earlier in the week. Ms200t was a working fine and I needed a refil so in went the aspen. I usually mix pump fuel.

Today it ran like a dog. Loads of power in the cut but I kept having to rev it to stop it stalling. I needed a refil. Used my own mix and grabbed a tuning driver to up the idle. It ran perfectly. New fuel, no adjustment...

Any ideas?

Always had issues switching betwixt pump & alkylate fuels, especially on idle. On older saws the fuel & impulse lines frig up & leak due to the absence of the chemicals required to counteract the corrosive nature of petrol. Magnus & Stig will probably be your best sources of info. I just avoid switching

 

[SkwerI]

I think it's because the different fuels have different burn characteristics/ energy output so of course they will burn differently. Your saw cannot automatically adjust between two different fuels so you need to tune them for the fuel you run and stick with it. This is why I never use anybody else's fuel.

I don't believe ethanol really has much to do with tuning issues, I think it is more because our gasoline comes in a summer and winter formula and they burn differently. I have to retune my saws twice a year when the gasoline changes. I know when it happens because all of a sudden my saws either won't idle or they idle really fast. If you are aware that the change in fuel is causing the issue then it's easy to address. Otherwise you start jumping to conclusions that your carb needs rebuilding or you've developed an air leak.

Like I said, if you only use the saw once in a while then the premix is worth the extra cost just for the stability and consistency. Unfortunately it's like $6 per quart so I can't afford to run it with as much fuel as I burn.

 

[Stumpshot]

We use 93 octane from the pump, preferably without Ethanol -- several stations around us have that. Don't really see the need for premix, seems expensive that way.

 

[Burnham]

I believe Stig and his crew runs premix...buys it by the barrel. They go through a lot.

 

[Tim_B.]

I have purchased and used the premix cans of fuel, in order to avoid putting ethanol into my chainsaw's fuel system, as well as a blower I have access to. I've read that ethanol is really corrosive, and dissolves the plastic parts of fuel systems. I don't run a saw very often, so do not mind paying the premium. Also, there are parts of the country where it seems like they try to make it very hard to even find fuel from a gas pump that does not contain ethanol. The northern Virginia/Washington DC metro area is like that.

I have not tried to find a marina that sells pure fuel yet, but if I all of a sudden needed to run small engines a lot, I would try to go that route. I think boats need the pure fuel to work right or something, which is why I'm guessing that the ethanol free fuel is available in those places.

I love how the stuff I've run using the canned fuel seem to run. Start right up, and run well, no issues.

Tim

 

[BlackSmith]

Pure-gas.org is your friend. Should be plenty of stations with corn free gas along the Potatomac.

 

[Stumpshot]

Hey, thanks! That's a great resource, esp, when you perambulate abound a 50 mile radius! However, I can attest that their octane ratings are incorrect in several spot checks. I just bought saw gas at Hyvee (grocery store) today and theirs is ethanol-free in the 91 and 93 (mid-grade and super unleaded), not 87. Also, Casey's General Stores has it in mid-grade. I'll have to give them a nudge to fix their Kansas & Missouri listings. Thanks again!

 

[BlackSmith]

It’s open source GP. I think you can get them to update the site real easy. Thanks belongs to Al Smith, he turned us on to the site long ago.

 

[Raj]

It shows my neighbourhood gas station is ethanol free, I asked them once and they didn't know...... Or spoke english....

 

[biggun]

I believe Stig and his crew runs premix...buys it by the barrel. They go through a lot.

As do most companies here in Norway.

I prefer to mix my own. The saws seem to run better.

 

[Robert P]

It shows my neighbourhood gas station is ethanol free, I asked them once and they didn't know...... Or spoke english....

Here they're labeled at the pump - it isn't that way everywhere?

 

[Raj]

Not in my area.

 

[Dave Shepard]

Around here premium is usually ethanol free. Mid grade is a blend, so I avoid that. When I mix gas I pump a gallon or two into the Jeep to clear the regular grade out of the hose, then fill my mix jug. I use Stihl HP Ultra, and have zero issues related to gasoline, even keeping it around for months in the summer. I was talking to a friend last night about this. He owns five John Deere stores, so he also sells Stihl. He said about the only thing that works for intermittent use is the canned stuff. They try to sell battery saws, trimmers, and blowers to the homeowner types that aren't using them regularly. It eliminates gas issues, as well as starting issues for some people.

 

[stig]

As do most companies here in Norway.

I prefer to mix my own. The saws seem to run better.

I've never noriced any difference in how the saws run.
I have, however, noticed that seals and other plastic/rubber stuff lasts a lot longer with Alkylate premix.

So do my lungs

We go through 4-500 gallons of the stuf yearly.

 

[Raj]

How much does that cost?!?!

 

[MasterBlaster]

A princely sum!!!

 

[Raj]

Up around my parts it's regular price is $9CAD/ L, on sale if you are lucky $7CAD/L.

 

[stig]

How much does that cost?!?!

Close to 10 grand.

Peanuts compared to what other expenses we have in a year.

 

[Burnham]

There you have it.

I have always maintained that fuel cost, be it saws, trucks, grinders, mini-lifts, etc, etc. are born by the customer. If you are eating profits by shielding your customers from the true costs you bear, then bad on you.

 

[Magnus]

I run only Aspen. If I am not sure the saw has run on it I pull cylinder and clean.

Be careful when shifting fuels and especially oils. It can have consequences.
About one or two percent of the saws that shift fuels get cooked. Not worth the risk in my opinion.

Some oils give carbon buildup. Some oils are penetrating and crawl in under this and it end up burning over piston.
If it can't get out right away it burns and is harder and harder. It looks like tiny bits of iron. Sometimes it gets between piston and cylinder. Most get out and rattle around in muffler.