041 Issues

[laynes69]

I have a 041 that my father gave me. It hadn't ran for a few years, and I go it running again. One thing I notice is that it doesn't have alot of power. When I put a load on it, it will pop. It idles fine, starts easy. The piston inside has some scoring on it. I haven't tore it down yet, but I'm assuming that my issues are probably low compression. It was a saw for a tree service before dad used it to cut for years. I want to possibly rebuild it. I've worked on alot of engines, but not chainsaws. I would think its worth rebuilding. Is it a task, and where can I get parts that are reasonable. Thanks

 

[Kenskip1]

In your posts you said that it starts easy and idles good.If it was low on compression then you would not have these symptoms. How about a new gas filter or maybe a carb kit? The 041 is a tough old saw.Mine still runs like a top but it is getting heavy, Ken

 

[laynes69]

Where should the carb be set? If it ain't set right, Maybe I will try a carb rebuild. Any cheap ways to run a few tests on the saw?

 

[Scooterbum]

Run a compression test.That's one saw that will sound like points breakin' down when the compression gets low.Had it happen with mine. It ran and idled good but when i put it wood it would pop and cackle like the ignition was breakin' down.

Carb should be about 1 turn out each for your starting point.

http://web.archive.org/web/20031013170039/madsens1.com/sawtune.htm

 

[laynes69]

I need to get a compression tester. Its pulls hard when cold, when hot, it pulls real easy. What all would it take to get it back up to par? I know rings, probably a piston. Thats where about I have the carb at. Once it gets hot, its alot harder to get started.

 

[Scooterbum]

Go ahead and pull the cylinder.Take some good close up shots and post them here.

I pulled a small 50cc Jonsered down today and found a stuck ring. Minor repair.Looked like someone had been using straight 30W for mix.Loaded with carbon.Cold it had 130lbs. and hot was about 60lbs.

 

[laynes69]

What all do I have to remove to pull the cylinder?

 

[Scooterbum]

Send me your email in a PM and I'll send an IPL.That'll show you.

 

[Scooterbum]

Their not too bad to tear down just a little time consuming.

 

[laynes69]

Well I tore her down. The bore is mirror smooth with no scratches. The skirt is worn pretty good. No gouges, but just plain out worn. How are those 25.00 kits on ebay? I figure I will do that, and put a carb kit in the carb. I noticed another thing, the piston in there now is a single ring. Whys the new one have a double ring? More compression? My other saw is an 025 with an 18" bar, and I wanted this one for larger trees. It has a 20" bar, plus nice to have at least a couple saws.

 

[jeeptj19992001]

Well I tore her down. The bore is mirror smooth with no scratches. The skirt is worn pretty good. No gouges, but just plain out worn. How are those 25.00 kits on ebay? I figure I will do that, and put a carb kit in the carb. I noticed another thing, the piston in there now is a single ring. Whys the new one have a double ring? More compression? My other saw is an 025 with an 18" bar, and I wanted this one for larger trees. It has a 20" bar, plus nice to have at least a couple saws.

i did one of those golf 25 pistons, works quite nice, now only if i could get my carb set correctly,

 

[laynes69]

Here are a few pics

 

[jeeptj19992001]

Here are a few pics

i would just do new ring

 

[Scooterbum]

i would just do new ring

+1

 

[laynes69]

Cool, should I touch the cylinder, or leave it? I know some cylinders were coated. A single ring would cause some compression loss? Anything else to check while Im in here?

 

[rmh3481]

Dont forget a new base gasket.

Best wishes,
Bob

 

[jeeptj19992001]

Cool, should I touch the cylinder, or leave it? I know some cylinders were coated. A single ring would cause some compression loss? Anything else to check while Im in here?

leave the cylinder, if it not scratch it is good. a single worn ring will cause compression loss, nope nothing else.
make sure you put the piston back in the right direction

 

[laynes69]

The arrow towards the exhaust right?

 

[blsnelling]

A single ring on a Stihl saw? All the Stihl saws I've seen, including a 041 Super, all had two rings. Is that an original Mahle piston? If so, it will be cast into the inside of the piston I believe.

 

[Dan-Tor]

A single ring on a Stihl saw? All the Stihl saws I've seen, including a 041 Super, all had two rings. Is that an original Mahle piston? If so, it will be cast into the inside of the piston I believe.

Yes, in those days stihl made 041's and 010's with only one ring then they changed for two rings.The same with 015's but without made change on them.