quote:

Originally posted by ensigmatic:
This was exactly what my brand new Echo backpack leaf blower was doing. Turned out to be a defective ignition coil. They replaced that and the problem went away.

Ok, adding that to the list of potentials. Thanks!

quote:

Originally posted by fritz:

quote:

Originally posted by valkyrie1:
I always use pre-mixed gas in a can. expensive but got tired of replacing carbs when the fuel messes them up

Bingo. The pre-mixed alkylate-based fuels are noticeably better fuels than what comes from a gas pump. Alkylate fuels are expensive, but IMO the cost isn't really significant in the long run -- unless you're cutting a lot. FWIW, I currently have 7 gallons of Stihl pre-mix fuel in my garage -- I cut a lot. I'm stocking up on holiday sales for my upcoming winter/spring cutting season.

I have reviewed a number of web-based tests on 2-cycle premix. Stihl often rises to the top. VP is also right up there, and it costs a little less than Stihl. Husky's fuel is respectable, but I don't feel it's quite as good as Stihl and VP.

Be careful of Trufuel -- the pre-mix alkylate sold at big box stores. Do a search on the web. Evidently their QC for the the fuel-to-oil mix levels can be spotty. To much oil and the engine doesn't run to its full potential. To little oil and the piston/cylinder is ruined. I'd go back to gas pump fuel before I would use Trufuel.

I was just looking at pre-mixed and given my "super-occasional" use, I think it makes sense. I suspect a quart would last me a good long time... certainly until the next time I head up to the mountains to collect a trailer load.

Does the premix stuff have a shelf life once opened? Think the Wal-Mart house brand is ok? I'm there often and they carry the Trufuel brand and their own Supertech brand.

The best option I've found is to buy the Stihl oil and 100LL Avgas from a small airport. The instructions are on the label but for the less frequent user like me the 2 gallons of gas to a bottle of oil works best.
The Avgas has excellent storage additives.

quote:

Originally posted by thumperfbc:
I was just looking at pre-mixed and given my "super-occasional" use, I think it makes sense. I suspect a quart would last me a good long time... certainly until the next time I head up to the mountains to collect a trailer load.

Does the premix stuff have a shelf life once opened? Think the Wal-Mart house brand is ok? I'm there often and they carry the Trufuel brand and their own Supertech brand.

Between what I've read online and what my saw shop states, the alkylate fuel mixes are supposed to be good for up to 2 years.

A quart of Stihl should run about $11-12. VP in the $9-10 range. Trufuel $7-9. SuperTech $7-8.

Consider if saving a few bucks every other year is worth the risk of buying fuel that will ruin your engine.

If you buy "gallons", look at the container to see if it's really a gallon. Stihl cans contain 128 ounces of fuel. Many of the "gallons" sold by other names have only 110 ounces of fuel.

quote:

Originally posted by fritz:

If you buy "gallons", look at the container to see if it's really a gallon. Stihl cans contain 128 ounces of fuel. Many of the "gallons" sold by other names have only 110 ounces of fuel.

Those jerks! Thanks for the good points and the info!

I run a fire department and fuel life is a real issue on specialized small equipment that we use infrequently. I have had direct conversations with the engineers at VP (whose fuel we use) and they have advised us a good shelf life for an unopened can is 2 years and opened cans 1 year. Now I get these are probably conservative give the use, but that's what I use as guidelines on my personal stuff.
As to your 025, my recommendations are as follows. This assumes you have done a decent physical inspection and the air filter isnt' clogged, the exhaust is free, the cooling fins are free of debris etc.
1. change the gas to fresh unopened fuel.
2. change the plug to a new correct one
3. change the in tank filter and most importantly the plastic hose that connects it to the carb. These are systematically destroyed by ethanol fuel and are a consumable.
4. make sure the fuel tank is venting
After that its stuff that costs money. Carb cleaning (replacement is always easier) and an ignition coil.
Good luck

I would hazard to guess the above covers prob 80% of what a small engine shop covers on a daily basis. And if it doesn't fix it, you prob needed all of the above anyway if you take it to a shop. All that is normal maintenance and all are prob due in your case with an old saw.

Thanks everyone. I feel like I have some solid things I can check out needing nothing but time and can move on from there. Now I just need to get to my next weekend to give it a go... maybe I can sneak some time in today to do the spark arrestor or air filter first.

If you want THE best advice for your small engine device problems, just watch Chickanic on YouTube. She’ll get you straightened out.

Re: Fuel.

For years I'd occasionally have problems with either our old 2-cycle snow blower or my Stihl 025 chain saw. Two or three times the verdict came back from the repair people: "Bad gas."

Several years ago, after having problems with the little 2-cycle snow blower again, I switched to Rec (Pure) Gas. Problems with that one went away.

Haven't had a single problem with any of our twelve small engine power tools {*} since.

I use Opti-2 2-cycle oil for all of our 2-cycle engines.

I'd say our fuel is usually cycled-though in about a year?

{*} Two snow blowers, two mowers, three chain saws, two leaf blowers, string trimmer, stick edger, backup generator.

Ok, first option eliminated. The problem was not the spark arrester. Pulled it out to clean it and re-installed. Same problem.

Will move on to another option.

95+% this is a fuel problem. start there.

Will pick up some premix fuel the next time I'm at a store with some, though it appears the most common brand around here, by far, is the Trufuel brand somebody cautioned against.

I can get the VP Racing brand locally, but currently only in the 40:1 ratio. Echo might be an option, come to think of it.

Are generic parts generally acceptable for things like air and fuel filters?

Does it have a primer bulb for the gas?

I have had them get hard and crack and do similar to what you have described.

Usually when the bulb goes the lines and most often the carb are all shot mainly from the ethanol gas as already mentioned.

I personally use to much fuel to buy the per-mix stuff. Find its a out as cheap to just keep extra carbs, fuel lines and bulbs on hand for everything I own and replace every few years as needed.

Be sure to have a look at the coil/magneto part I suggested earlier. Have a spare plug nearby so you can check for spark before cooling down after it dies.
The symptoms I had were exactly the same as described.

quote:

Originally posted by Mustang-PaPa:
Does it have a primer bulb for the gas?

I have had them get hard and crack and do similar to what you have described.

Usually when the bulb goes the lines and most often the carb are all shot mainly from the ethanol gas as already mentioned.

I personally use to much fuel to buy the per-mix stuff. Find its a out as cheap to just keep extra carbs, fuel lines and bulbs on hand for everything I own and replace every few years as needed.

No priming system on this O25. I like cheap, but my use for this thing will be VERY occasional, at best.

No more anything to cloud suggestions. Among other things, I grew up with Polaris snowmobiles back in the 70’s. No conveyance left one stranded as often as a snowmobile.

As the uncle would dictate, fuel, air & spark was always the biggies. Once you eliminate all the easy things, it may be time for the pros.

Yes, fresh fuel & carb cleaner can be a biggie.

quote:

Originally posted by thumperfbc:
Will pick up some premix fuel the next time I'm at a store with some, though it appears the most common brand around here, by far, is the Trufuel brand somebody cautioned against.

quote:

Originally posted by ftttu:
If you want THE best advice for your small engine device problems, just watch Chickanic on YouTube. She’ll get you straightened out.

Chickanic has 3 videos which address issues with Trufuel. Trufuel seems to work for some folks, but sure has issues with 2-cycle engines dropped off at Chickanic's business.

somebody ran 3 tanks of Stihl fuel through Stihl 400 and Stihl 310 saws yesterday on family property, felling trees #116 and #117 for 2024. The fuel consumed yesterday finished off yet another gallon can of Stihl fuel and another of bar oil. Stihl fuel has been flawless for somebody's saws. Maybe 2 gallons of VP gas consumed during the year, but 90-ish percent has been Stihl gas. Here's tree #116 -- 25 inch diameter at the felling cut, 70 feet tall.

Can eliminate the air filter today.

So far the problem is NOT:
- clogged spark arrestor
- clogged fuel vent
- dirty air filter

I picked up some premix fuel today, STP brand, so I can dump the fuel that’s in it and replace with fresh premix to see what happens.

If the fuel doesn’t solve it I’m thinking of spraying the carb down with some carb cleaner… or pulling it and then spraying it. Don’t need anything I don’t have on hand to do that.

You can try this also https://b3cfuel.com/product/mechanic-in-a-bottle/

Since its an older saw, any rubber part is suspect, age, drying out, ethanol damage etc.

Possible issue fuel line, even a pin hole could cause issues

https://youtu.be/JjQouxSr1n8?si=uf3Q0rOTJxpSDK-S

And a how to replace
https://youtu.be/2Sh90_ax9K8?si=ZLCa-PtcV5yBNJOz