Sthil 028 basketcase

[Mafun464]

Hello i have a 028 that i finally got to spark on. Now i have a fuel delivery issue will run with the air cleaner soaked in two stroke or gas down the carb. Repaced impulse lines and fuel lines. next thing im getting tank vent. Any ideas to help me not chase a ghost issues.

 

[Mad Professor]

Tank vent is just a piece of fuel line with screws in it. Should be able to see if clogged. If you replace, push the screws in don't screw them. If you screw them they will cut into the line and block it.

I'd also take a quick look at the carb.

Check that inlet elbow is not loose/cracked. The special washer and sleeve are in place where the carb mounts to intake boot, intake boot not cracked.

Carefully take off carb end cover and check that sawdust has not clogged up that keeping the diaphragm from moving and the diaphragm is intact. There is also a screen on the inlet that can get clogged with gunk. If you tear any gaskets or rubber parts you'll need a cab kit.

Which carb do you have?

 

[Mafun464]

Tank vent is just a piece of fuel line with screws in it. Should be able to see if clogged. If you replace, push the screws in don't screw them. If you screw them they will cut into the line and block it.

I'd also take a quick look at the carb. Check that inlet elbow is not loose/cracked.

Carefully take off end cover and check that sawdust has not clogged up those keeping the diaphragm from moving and the diaphragm is intact. There is also a screen on the inlet that can get clogged with gunk. If you tear any gaskets or rubber parts you'll need a cab kit.

Which carb do you have?

Not sure on the carb have to go look at it. Vent line leaking to begin with so it getting swapped. I have another carb i can throw on it. This saws seen a few to many hand and randomness

 

[Kevin in Ohio]

To test a vent issue, leave the cap loose and see if it'll run ok. Generally, saw will start and run fine till it pulls a vacuum. I do have an 028 and it did have a vent issue. It always started fine with normal choke procedure. If you haven't yet, dump the points and go electronic. Weak spark will drive you nuts. This 028 was picked up from a neighbor on trash day. Saw the box of parts and grabbed it. Had been to a dealer as it had their tags on it. Must have decided to buy new after they "convinced" them. Great compression and had spark but wouldn't hit a lick. Finally tried electronic ignition and it has run ever since(5 years) like a scalded dog. Just because you see spark when the plug is out, doesn't mean it's good when it's in. Never forget that.

 

[HarleyT]

If you have the carb off, take a peek at the piston from the intake side.
If you think it is ignition, just pop on a good 029/290 coil and do away with the points.

 

[Wood Doctor]

Harley, I am in the process of doing exactly that (to install a new coil) with an early 028 WB that shows no spark at all. Until I get a spark to show, that's my usual procedure. On the other hand, OP said he "finally got to spark on". He moved on to the fuel system.

Once I get a spark, I think the saw I am working on just might run, but until I do, I know it will never run.

 

[Mafun464]

Harley, I am in the process of doing exactly that (to install a new coil) with an early 028 WB that shows no spark at all. Until I get a spark to show, that's my usual procedure. On the other hand, OP said he "finally got to spark on". He moved on to the fuel system.

Once I get a spark, I think the saw I am working on just might run, but until I do, I know it will never run.

I riped the point out for a 029 coil so im on to fuel as long i feed it gas it as happy as can be just wont suck from the tank saw got some decent compression

 

[Mafun464]

If you have the carb off, take a peek at the piston from the intake side.
If you think it is ignition, just pop on a good 029/290 coil and do away with the points.

Has a 029 coil has very good and aggressive spark when it has fuel kick right away just wont suck from the tank so im replace vent

 

[SteveSr]

Has a 029 coil has very good and aggressive spark when it has fuel kick right away just wont suck from the tank so im replace vent

The original filter/pickups in these had foam rubber inserts. Over time the foam rubber would disintegrate and get sucked into the screen on the carb cutting off fuel flow.

Pull the carb and check the pump side screen for clogging. If found clean out the carb and replace the fuel pickup and fuel line for good measures.

 

[HarleyT]

He says that the ignition is ruled out.
Points saws can fool a guy.
But from his description, he needs to look at the intake side of the piston.

 

[HarleyT]

I think I have confused this 028 with one II am commenting on in Facebook.
Here after rereading, a good carb cleaning/rebuild should be next, and while the carb is off, look at the piston skirt.

 

[Mafun464]

I think I have confused this 028 with one II am commenting on in Facebook.
Here after rereading, a good carb cleaning/rebuild should be next, and while the carb is off, look at the piston skirt.

What should i be looking at for the piston skirt. Definitely probably gonna either carb kit it or give up and send it to the sawshop

 

[HarleyT]

Well then don't look at it.

If you have the carb off, why wouldn't you look at it? Many folks have invested a lot of time and money to finally discover that the piston is toast. I have seen good looking saws do crazy things, and the piston look great from the exhaust side, and after a lot of time and money later, it is discovered that a big chunk is missing out of the piston skirt.
So yes, if the carb is already off,
take a peek.
From what I have read over again, I would say a correctly done carb rebuild is in order.

 

[Mafun464]

Well then don't look at it.

If you have the carb off, why wouldn't you look at it? Many folks have invested a lot of time and money to finally discover that the piston is toast. I have seen good looking saws do crazy things, and the piston look great from the exhaust side, and after a lot of time and money later, it is discovered that a big chunk is missing out of the piston skirt.
So yes, if the carb is already off,
take a peek.
From what I have read over again, I would say a correctly done carb rebuild is in order.

Okay ill pop carb off again. I think i looked at piston but cant remember now ive just been dinking around with this saw here and there. I just wanted to know if there was something special i was looking for besides damage. Thank you

 

[HarleyT]

Yeah, always take a peek at the piston if you are in there. Nothing worse than buying a bunch of new parts to find out the piston has damage.

 

[Mafun464]

Yeah, always take a peek at the piston if you are in there. Nothing worse than buying a bunch of new parts to find out the piston has damage.

Got the saw for nothing so doesnt bother me also have a decent case i think decent piston just have to look

 

[HarleyT]

Yeah, if the intake side looks bad, you also might listen for bearing noise, and other issues.

 

[Brushswamper523]

I am going to be honest here I have an 028 super threw a few bucks at. I never pressured or vac tested it. Got frustrated threw it under the bench for a year. Decided to work on it earlier this year did a pressure /Vac and it had seal leaks bad. Might want to test there. Just a suggestion. Also you can test the line and all that with pressure and vac test.

 

[SteveSr]

I am going to be honest here I have an 028 super threw a few bucks at. I never pressured or vac tested it. Got frustrated threw it under the bench for a year. Decided to work on it earlier this year did a pressure /Vac and it had seal leaks bad. Might want to test there. Just a suggestion. Also you can test the line and all that with pressure and vac test.

Any 028 is old enough to need seals prophylactically. One less potential problem you WON'T have to fix next!