Help with Old Stihl 028

[ScipioUSA]

Been a while since I have worked on my saw, but isn't there a crankcase vacuum hose to the carb to supply the pressure pulses to operate the fuel pump on the bottom of the carb. I remember not getting fuel because I had not found a bad hose.
I also remember a lot of new chinese carbs which did not work and now look for OEM carbs.
The emission control carbs on the new saws don't rebuild well, but the old carbs rebuild OK with a good kit.

Yes, the 028 has an impulse line for the carb. Those can go bad, always good to replace when unsure of the condition.

 

[4Liberty]

That saw doesn’t have a compression release.

Sorry guess I thought all the MS series saws had one. That being said when I saw the pic of your piston/exhaust port my mind went right to that. That being said I’ve seen several rebuilt saws that did just that due to malfunctioning/dirty compression releases. It will lean them out big time if it’s sucking air, and they make plugs to eliminate them just for that reason.

 

[4Liberty]

My saw, a different stihl, has a compression release. Is there a problem with using these?

They make a plug to eliminate them for a reason. When the saws were new they worked great. After issues somewhere else and metal flying around where it shouldn’t, or just old age they can stick open, suck air, lean out and that’s no good. They are cheap enough just to replace on rebuilding or just eliminate them.

 

[dodge man]

I think compression release is just on pro saws? I posted when this happened and asked the cause. The general consensus was straight gas. I wasn’t the sole operator of it but almost. That said I did lend it out once and it still could’ve been me that did it. It required a new jug along with a new piston.

 

[4Liberty]

I think compression release is just on pro saws? I posted when this happened and asked the cause. The general consensus was straight gas. I wasn’t the sole operator of it but almost. That said I did lend it out once and it still could’ve been me that did it. It required a new jug along with a new piston.

Sucks when that happens. I haven’t personally had it happen but my time is probably coming. It doesn’t take much to foul up something running rpm like they do. And it’s really easy for some piece of junk to get stuck somewhere only to find it’s way when it’s running.

 

[alana1]

Long story short, I have enough chainsaws to remove the entire Brazilian rainforest if needed. That being said, take the 30 mins required to replace all the fuel lines to and from the carb. Thats the biggest issue with most of these saws. Amazon sells kits or your local hardware store for under $10. You will be a happy wood cutter in no time

 

[gatornapper]

One thing to consider is possibly that the base gasket/seal between the cylinder and the case may be leaking.

Yes - this is exactly what killed my Stihl 021 I ran for 25 years that suddenly would not start. Can be fixed, but best just buy a new saw.....

GN

 

[777Airmech]

Not a big poster here but wanted to let you know I have never had any luck with the Amazon Chinese carbs. I have a Echo Trimmer that I was trying to fix because it was just given to me from a friend that was moving. Until I bought the manufactures carb it did not want to run at all. You may think your saving money but how much is your time worth (i spent hours), and do you want it to be a dependable saw What good is it of your always messing with it ? I just pay the money up front the first time and be done with it...The posters here have had a lot of good info and if you have done it all (Compression, fuel lines, the little filter in the tank, I would go back to the carb, also check the spark plug if its dumping fuel, clean it and make sure it dry.... Hope its fixed soon!

 

[dodge man]

I’ve also had bad luck with cheap carbs, in my case a Lawn Boy two stroke.

 

[WinterDeere]

Opposite experience, here. I have replaced many leaf blower or chainsaw carbs from Amazon, and have never received a bad one. Maybe I just pay more attention to the reviews, than some of you guys?

They do sell some junk, but also some parts with long records of satisfied customers. Buy the one with 1200 reviews averaging 4.7 stars, not the one with 6 reviews averaging 2.3 stars.

 

[xyz123]

IMHO dont use that cheap yellow tygon lines. Even worse is the no name cheap yellow and clear lines.

I take that crap out of every saw that comes in with it. It will last about a year before it starts to harden. Some times shrinking and leaking too.

Use good OEM lines like echo, husky, stihl as replacements. I use echo even in stihl saws like here.

 

[xyz123]

Opposite experience, here. I have replaced many leaf blower or chainsaw carbs from Amazon, and have never received a bad one. Maybe I just pay more attention to the reviews, than some of you guys?

They do sell some junk, but also some parts with long records of satisfied customers. Buy the one with 1200 reviews averaging 4.7 stars, not the one with 6 reviews averaging 2.3 stars.

Same here. You just got to know which ones to buy. Not all clone carbs are the same. Some makers better and good results.

Like this afm carb put on clone 460. To replace the 460 carb that was iffy. The 460 carb brand was known to be iffy. The 440 carb like on my other clone 440 was known dead reliable. So another one of those on it. 20-25 shipped way cheaper then a oem 440 460 carb.

 

[areid]

For what it's is worth, I have had two separate issues with my Sthil saw. The plastic line in the fuel fake has cracked twice. Won't start. The second issue is a carboned up exhaust screen. Burned it off the screen and away it went. Otherwise im as green as grass when it comes to chain saw repair.

 

[Fxfymn413]

A fast compression check can be done by picking the saw up by the pull handle. If the saw's weight allows the pull rope to extend out so the saw falls the compression is suspect.

Stihl saws are very easy to flood. Once it kicks over once with the choke on you need to open the choke or it will flood.

Check the muffler to make sure it is not clogged as well.

 

[xyz123]

@Fxfymn413 if you read the thread OP already gave all that info on compression. = Compression is between 135-140

 

[rocco611]

"If I can get it to run it basically red lines itself, max RPM." this sounds like an air leak from the base gasket or crank seals. If you have checked eveything else you could take it to a saw shop and have them do a pressure test on the crankcase.
That is still a very popular saw, check out youtube videos on teardown and repair of this saw. I rebuilt one recently that I got from a neighbor. Pretty much all the rebuild parts are available aftermarket . Once you understand how to work on them its pretty easy to completely go through one and have a great running saw.

 

[manzer7]

Hi all,

I picked up an 028 for $10 at a scrapyard back in April, and been messing with it off and on since…still can’t get it to run. Been taking up space on my workbench and I figured I might get some help here.

Bottom line, something is messed up with the air/fuel delivery. I have spark, compression, and I can get it to run with ether for about 2 seconds so I think the magneto is fine. If I can get it to run it basically red lines itself, max RPM.

I have a new Chineseium carb, replacing the (also looked new) chineseium carb it had on at the scrapyard. I haven’t messed with the idle screws on this new one yet.

I have a few questions with pictures:

First, I replaced this cracked line, looks like a fuel tank vent but it doesn’t lead anywhere. Is this correct looking? Also, not sure what the broken ground wire is supposed to be/do. I have good spark.

View attachment 4692594

Next, when I have choke on, the butterfly is slightly open, more so than when choke is OFF. Seems it should be the other way around, cutting down air when choke is on. Is this supposed to be this way?


View attachment 4692595

Choke off:

View attachment 4692596

Finally, when I flip the saw to off, this black wire makes contact with a metal bar. Is this essentially shorting the spark to ground, shutting it off? Just wondering for my own knowledge:

View attachment 4692597

Here’s how the saw has looked the past 8 months…I appreciate any help! It’s a pretty cool saw, made in West Germany.

View attachment 4692598

I have an 026 and my problem is the gas line - it is not working with the new gas mixture and has smelted the gas line and I CANNOT find the correct gas line to fit it. I do get it to go but it dies to lack of gas. I bought this new back in 1980's ? I bought a brand new Stihl MS261 that works fine. When I do find the correct part - I will be using it again - that is the best lightweight chainsaw !!!

 

[Atlas55]

Typically on 028s the crankshaft seals fail and there are no replacements. This is usually why 028s are found in scrapyards. They were a great little saw in their day

 

[Eagle1]

Seems like there are several people making and selling crankshaft seal for the 028. YMMV
BAO/NW double lipped crank crankshaft seals for Stihl 028, AV, Super - Wolf Creek Saw Shop

Cheaper ones at other places, Amazon, Ebay. etc

 

[Bentrim]

Have read most of the posts and notice no one has mentioned the carb to cylinder boot. If memory is any good I know some Stihls used a metal ring in the carb end of the boot
If you don't have recommend you purchase a hand held vacuum/pressure pump, plug the exhaust and intake port and take a vacuum pressure test of the cylinder/crankcase. Take a compression test and should at bare minimum 100psi although more is better.
As for trouble shooting it sounds as if you have proved ignition, but have a fuel supply issue or a leak. The pressure/vaccum test would prove that. If a fuel issuel be sure the tank, filter, and supply line are clean and the fuel line free from cracks and breaks. And one last point be sure the pulse line is in good shape and is aligned at the carburetor.