For decades our family mixed regular pump gas plus the small bottles of oil for our chainsaw fuel. To be honest, we had issues:
- The saws often ran poorly in the winter.
- The saws didn't start well after sitting for months.
- We replaced saws on a 5-7 year basis, when the saw repair shops said they were end of useful life. I recall carburetor and compression issues were the general problems.

A number of years ago, Dad decided that I was using his Stihl 310 (2003-vintage) saw so much that it should be mine to keep and maintain. When it didn't run worth a crap one spring, the shop had to replace the carburetor and fuel lines. Upon the shop's recommendation, I switched to non-ethanol pump gas. The saw ran noticeably better -- and starting was more consistent, especially after sitting for a month or three. I immediately noticed the difference in fumes & smell -- the non-ethanol gas didn't stink nearly as much. With regular pump gas I could smell the exhaust fumes (in my nose, I guess) for a day or two after sawing. With the non-ethanol pump gas, the exhaust smell was gone by the next morning.

I tried pre-mix alkylate fuel one day when I was out of the non-ethanol gas mix, and the only nearby non-ethanol gas station's pumps weren't working. I bought Stihl fuel at the local saw shop. My Stihl 310 ran better than it ever had before. There was almost no smell of exhaust, and my clothes didn't stink of 2-cycle exhaust afterwards. I used Stihl fuel for the next few years. After a bunch of hard use, the Stihl 310 needed some repairs -- oiler, clutch assembly, bar, filters, carb adjust. My Stihl dealer tore the 310 down, checking all parts, doing a compression check. They stated the cylinder & compression chamber were in amazingly great shape for a hard-use saw that was almost 20 years old. They said that if am willing to pay the freight, keep on using pre-mix Stihl fuel.

I primarily use Stihl premix. If Stihl isn't available, VP is choice #2. VP seems about the same, but with just a slightly stronger oil smell from combustion. I've tried a couple gallons of Husky premix fuel. I thought it smelled worse than VP -- but way better than any pump gas. The Husky premix fuel didn't perform as well as Stihl or VP in the winter. My 3 Stihl saws all run well with Stihl premix - 310, 261, and 400.

******
Here's a test of Stihl, Husky, VP, and Trufuel.
Premix Fuel Test - Stihl vs Husqvarna vs VP vs Tru Fuel 50:1

This guy ran a gallon or two of each fuel through a new-ish Stihl 661 saw. He changed out the cylinder & piston with each type of fuel -- i.e. new cylinders & pistons for each run. Then he disassembled the engine, and reviewed the results.
- All 4 fuels ran well. There was no evidence of bad engine wear with any of the 4 fuels.
- He noted that the Stihl premix produced the cleanest combustion chamber, cylinder, and exhaust port.
- He felt the least offensive exhaust smell came from the VP and Trufuel.
- He stated the Husky fuel had the least amount of oil in the engine's bottom end, which was concerning.

After watching several Chickanic vids, water in fuel is the biggie. She did a short time lapse of how fast and how much water gas attracted water out of the air. Others are fuel lines and fuel filters, clogged spark arresters, bad carb settings, fouled/burned plug, bad coil/other ignition components, and using certain premixed fuels. The usual for engines, but the popular premixed fuels was eye opening for me.

I’ve had the saw on standby while I wait for parts and have been tinkering with a little Craftsman blower I picked up for $10 instead… possible future thread topic right there.

But this morning I decided to pull the starting rope assembly thing off to get a look at the ignition module and I found it absolutely caked in oil sawdust. Anyone think the high level of gunk can be contributing to my problem?

I’ve scrapped out most of the gunk but this thing could honestly use a bath in degreaser and a good rinse. Is that possible or will it hurt things?

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Ive had mine pretty grungy. I scraped most out and then used an air compressor to blow out any loose junk. I then sprayed braked cleaner on a rag and wiped to get the stuck on parts. More air to finish. I dont know if i would spray cleaner into the unit.

I wouldn't say the grunge is a cause, but it certainly doesn't help.

Well....that looks nasty. I agree that the grunge probably isn't the primary problem, but it isn't helping.

Webz lore often sez don't pressure wash a chainsaw. But I regularly hose mine down at the car wash, after a big day of cutting. Because I generally need to hose down the 4Runner for cow turds in the wheel wells.

Never had a problem with pressure washing, but I don't go full power up close on electronics or carb areas. A clean saw makes it easier to review for obvious damage or problems. A clean saw makes chain sharpening an easier job. My Stihl dealer/shop says they like working on my clean saws. They showed me how bad some of the ones in for repairs can be.

I’ll get it cleaned up and re-gap the current ignition module while I continue waiting for a small box of parts apparently on a slow-boat from
China.

Parts are here. I know what I'm working on this weekend!

https://youtube.com/shorts/frMGz2Ug4PA?feature=shared

All fixed! New chineseum coil, new fuel line and filter, and mostly taking much of the carb apart and spraying it down and blowing it out with the air compressor and I think this thing is fixed!

On to the Craftsman leaf blower I picked up that was sold as “won’t start”

That sound nice.

Now go cut some wood

The coil wire leading to the plug was crunchy as heck… it sounded like Rice Crispies when I was handling it, plus it was fraying and some conductor was visible. It was clearly due for change.

Thanks to those who suggested the coil!

Idle and high speed both sound good. Throttle response is good.

Your chain stops quickly upon idle, so it appears your clutch springs are still good. If anything I'd say the chain stops a hair sooner than I'd expect -- make sure the chain isn't too tight and that the bar is getting adequate oil.

Now it's time to cut some wood.

quote:

Originally posted by fritz:
Idle and high speed both sound good. Throttle response is good.

Your chain stops quickly upon idle, so it appears your clutch springs are still good. If anything I'd say the chain stops a hair sooner than I'd expect -- make sure the chain isn't too tight and that the bar is getting adequate oil.

Now it's time to cut some wood.

That reminds me, I’m not entirely sure how to find the right chain tension. I’ll have to look into that.

The carb on this chainsaw has no high speed adjustment screw. Is that normal for its age?

I have a saw vintage 1993, Stihl, it has the carb adjustments for altitude. I think they were around well before that.

I have a newer, better, larger Stihl, so I normally use that.

My older Stihl has never run well since I took it elk hunting at 8,700’ elevation. I tried most everything, including 2 shops.

quote:

Originally posted by thumperfbc:
That reminds me, I’m not entirely sure how to find the right chain tension. I’ll have to look into that.

The carb on this chainsaw has no high speed adjustment screw. Is that normal for its age?

There are videos on the web which show how tight a chain should be. If it makes sense, for your length of bar...
- Pull the chain away from the middle of the bar with your fingers.
- You should be able to see daylight between the bar and the chain, but you should not be able to pull the drive teeth all the way out of the groove in the bar.
Basically a guideline, as your saw might have a sweet spot, given your type of cutting.

From what I've seen on older Stihls, you should have 2 or 3 screws to adjust the carb. Check the web. Your saw seems to run pretty well now.
Some people are skilled enough to adjust the carb by ear. The most accurate way is to have device which measure engine RPMs.

quote:

Originally posted by fritz:

quote:

Originally posted by thumperfbc:
That reminds me, I’m not entirely sure how to find the right chain tension. I’ll have to look into that.

The carb on this chainsaw has no high speed adjustment screw. Is that normal for its age?

There are videos on the web which show how tight a chain should be. If it makes sense, for your length of bar...
- Pull the chain away from the middle of the bar with your fingers.
- You should be able to see daylight between the bar and the chain, but you should not be able to pull the drive teeth all the way out of the groove in the bar.
Basically a guideline, as your saw might have a sweet spot, given your type of cutting.

From what I've seen on older Stihls, you should have 2 or 3 screws to adjust the carb. Check the web. Your saw seems to run pretty well now.
Some people are skilled enough to adjust the carb by ear. The most accurate way is to have device which measure engine RPMs.

I must have seen the “teeth” method somewhere as that is what I did, actually. Pulled up on the chain at the middle of the bar looking for some slack but not so much that the “teeth” exited the channel. I’ll verify the next time I am out in the garage.

It seems this model saw had multiple versions, some with a fully adjustable carb and some without the high speed adjustment. Apparently mine is the non-adjustable one, but if everyone agrees it sounds like it’s running well now I don’t see a reason to worry about it.

Now to find some wood to cut…