I have a Stihl gas trimmer. It is frequently difficult to start. My garden center says it is because of the ethanol in the gasoline. They claim the oil/gas mixture should not be used if more 2 months old. And even month old gas can cause problems. But, I have used cheaper brands in the past without this problem, even after the oil/gas (with ethanol) mixture had sat over winter.

Is this problem peculiar to Stihl, or all new trimmers sensitive to ethanol? What brands are most tolerant of ethanol?

Thanks,
Walt

You have to stop being a cheapskate.

1. Use High octane fuel

2. Use a 2-cycle oil that's formulated as 1 bottle for gallon.
Stihl makes a synthetic version with gasoline additives.

If your not using anything with gasoline additives, then you need to add some yourself. Products such as Sta-bil can only be added to FRESH gas.

If the gas is going to around for a couple of months it's imperative to use the stabilizer. For both 4-cycle and 2-cycle gas, I make sure the stabilizer is present when I get my gas near the end of the season.

The fuel system changes to gunk without it. It's best to drin/run the fuel out before mowers are stored for the winter.

1. I use 93 octane.

2. I use Stihl oil: 1 bottle to a gallon as per directions.

3. I don't use the stabilizer because the Stihl vendor said it wouldn't make any difference.

A gallon will typically last me 3 to 4 months. I could use it one month and dispose of the remainder if necessary. But that was never necessary with previous brands. I bought the Stihl thinking it was a superior machine. If this is a Stihl problem, I would rather buy another brand and eliminate having to dispose of the extra gas. ( My little part in environmentally safe practices.) If this is a generic problem with all newer 2-cycle engines, then I'll deal with the disposal issue.

Everything looks good.

Take a look at your Stihl oil bottle and see if it says it contains fuel stabilizers.

I just bought the synthetic oil and it does. I do know that the non-synthetic oil was available too, but I don't know if it contains fuel stabilizers.

This link STIHL Ultra 2-cycle Oil - Tool Shed Forum - GardenWeb makes things interesting.

Looks like I'm going to have to do some more goggling: Two Cycle Oil for Air Cooled Engines

In the past I've used Echo oil partly because I bought an Echo blower. I blew up the Echo blower a few times and Echo offered to give me my money back or offered a downgrade to a blower that didn't have the design issue whose rareity affected me because of the types of leaves I was picking up.

I ended up buying a Stihl and have used the Echo oil and the Stabilizer.

I just bought by first pack of the Stihl synthetic which contained stabilizer. I've used about 5 tanks (blower) so far and I think I like it better.

Now, I do always rock the blower back and forth to promote mixing before starting when there is fuel left in the tank.

I haven't had any problems starting the Stihl, but occasionally I have to run at part choke. The Echo I had numerous starting problems with.

I do change the plug every season and either replace or clean the air filter. The dirty air filter gets tossed in the washer and washed with jeans.

Let's see what we can come up with.

Stihl doesn't mention it on their website 2-Cycle Engine Oil and Lubricants - STIHL Incorporated USA -- Products -- Manufacturing the World's Number One Selling Brand of Chain Saws that the lubercants have or don't have a stabilizer in it. 2-Cycle Engine Oil and Lubricants - STIHL Incorporated USA -- Products -- Manufacturing the World's Number One Selling Brand of Chain Saws but the bottles of synthetic I bought definitely said yes.

There is a mention of biodegradable of 80% in 21 days. I'm not sure what that exactly means. It does make you wonder, though.

I did a little more research. Ethanol seems not to be recommended for trimmers primarily because of settleing, I guess that when I always try to mix the oil/gas mix remaining in the blower and evem when I pour gas from the can I probably avoid this issue.

Secondly this review of 2 cycle ols in airplanes seems to recommend Belray H!R oil.

The oils used did seem to make a difference.

I may switch to it too, but it will take me a while to use up what I have.

Keep it simple...

Thanks for the help. I wasn't able to find the Belray oil, but will keep looking. But I think the best solution might be to mix smaller quantities of gas. Basic math and a measuring spoon should do the trick. I'm also going to start using the Stabilizer even though the Stihl distributor said it wouldn't help. Hopefully reducing the quantity to a 2 month and adding the stabilizersupply will solve my problem.

Thanks for getting back. Appreciate it.

Bel-Ray: Looks like motorcycle store might have it. You can always get it online.

Bel-Ray MC-1 2-Stroke Oil - BikeBandit.com


Here is a mixing calculator I found online.
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As I had said, I tend to use the stabilizer later in the season. When I feel I got may last tank for the lawn mower, I add stabilizer. I do drain the lawn mower tank for winter.

For the 2-cycle, since I really don't use it much during the summer and I use it in bursts in the fall (4 tanks a day) for 4 or 5 weekends. That gas gets stabilizer right away.
I generally don't drain the tank.

Good luck. I guess I have an experiment too. Fully synthetic Stihl oil. I just don't understand the 21 day biodegradeabe.

I just sent an email to Stihl from their website concerning this. We'll see what happens.