Stihl 028 Carb and another problem

[retoid]

Hey guys,
I picked up an used 028 a little while ago and ended up replacing a few things, the fuel line, fuel filter, spark plug, bar and chain. I could get it running for about 10 seconds and it would die. So then I gave the carb a complete rebuild, replacing the washers, screen, diaphragm and the needle part. (not sure what it's called)
After tuning the high and low speed on the carb I could get it running a bit longer but still after a bit it would die, if I gave it any throttle it would die almost immediately. I got frustrated with is and ended up taking it down to the local saw shop, they told me I needed a new washer and needle bearing on the clutch. One of the washers was shattered and completely gone (as you can see in the first photo). And the needle bearing was pretty bad as well. The told me that the saw ran just fine without the bar and chain obviously. So I replaced those parts and put her back together, tried running it with no luck. Shot some fuel right into the carb and got it running for about 20 seconds idling before it would die again. I tried giving her a bit of throttle and at a certain point it would choke and die. So I tried one more time without the bar and chain and noticed that this "loose washer" in the photo below was rattling around a bit. Is there supposed to be a bit of play between this washer? I was thinking that the e-clip was to hold it down tight? Anyways I got the same result, it would eventually die.

Any suggestions?

Thanks

 

[retoid]

I also wanted to ask about the Oregon Powermate sprocket. Whats the word on this? Any good?

 

[retoid]

Damn I am stumped at this point.

I removed the bar and chain and can fire it up on full choke but it will only idle for a bit on full choke, i knock it to half choke and it idles for about 1 minute and eventually dies, then it won't run at all, I'll let it sit for a minute and try again on half choke and it fires up and idles for a bit. Sometimes, if I give the throttle a little tap, it will stay idling after I take the choke off. Sometimes it will just die. If I give it full throttle at all it will choke out and die, when I let go of full throttle it dies.

The current high and low speed adjustments are: (how it was given back to me from the local saw shop.)
H: 1 turn
L: 1.25 turns

It seems almost that the fuel is getting held up at somewhere. I tried it with the gas cap half on so eliminate a possible vacuum but it gave me the same results.

Any suggestions would be greatly appreciated.

Thanks

 

[smilin possum]

Did you replace the pulse line sounds like it's not getting gas to run past idle. A pin hole will cause a big problem. That or the carb needs to be checked again. The needle and seat may be sticking or the diaphram is leaking.
Good luck,
Joe

 

[retoid]

Just checked the carburetor again, made sure everything was in place, tight and clean. Everything was correct and the needle is not sticking.

I'll pull out the impulse line and test that.

 

[retoid]

Quick question, what is the best way to get to the impulse line?
Sorry to throw out such an amateur question. Does the tank/handle assembly need to come off?

 

[adkranger]

Quick question, what is the best way to get to the impulse line?
Sorry to throw out such an amateur question. Does the tank/handle assembly need to come off?

It does unless you are really good........and have tiny, long fingers.:jester:

Usually the rear handle/tank assembly is removed, but I have done them w/o total removal. I wouldn't recommend it for a first timer though, real easy to tear/rip the intake manifold. Then your $2 fix turns into about a $32 fix.:msp_scared:

 

[Fish]

You might want to look at the ignition.

 

[Clarkbug]

I also wanted to ask about the Oregon Powermate sprocket. Whats the word on this? Any good?

Im curious about this same thing....

Also, have you pulled the muffler at all? Any chance the screen is plugged up there?

 

[Mad Professor]

Check the fuel tank vent and /or see if it will run with the gas cap a bit loose.

The vent line is just a small hose with a screw inside it (grub screw), looks like a small allen head set screw.

 

[retoid]

Ok, I've got the tank assembly removed. I removed the impulse line, it looks to be in good condition, no tears or any signs of holes. I tested it with compressed air.
The ignition is fine, not sure how that would come into play with my current problem cause I can get it fired up.

The tank vent looks fine, no cracks in the line and it still feels in good condition.

I might as well replace the impulse line while I have the saw apart again. Though I am doubtful that it's the problem.

When I give the saw full throttle it sounds a lot like this guys saw.
http://www.youtube.com/watch?v=2n59Jj849b4&feature=player_embedded

 

[Fish]

With the carb completely disassembled, you need to visually verify that the passage
below the needle is clear. The older fuel filters had a foam insert that would break apart after 20 or so years and clog that passage with debris, it would let enough
fuel pass to start and run, but starve the engine when the throttle was applied.

Also, don't rule out the ignition just because you can start it. Does the saw have points?

 

[retoid]

Ok, checked the carb again, removed the needle and screen, below you can see there is no debris and it seems clean and clear.

By points are you referring to High and Low Speed adjustments? If so it has H and L yes. The local saw shop tuned it for me, said it was set to: L - 1.25 turns, H - 1 turn.
The saw case says it should be set to 1.25 turn each.

 

[Mad Professor]

Disconnect fuel line from the carb and bend it back and forth, look for tiny cracks.

I has a similar problem with a 038.

 

[Fish]

Since you are ready with a good camera, take off the starter, blow out the crud, and take a pic.....

 

[skooter]

Hi had some what of the same problem with a husky what I had found the wire going to the shut off switch came off and it was causing the saw to run like yours is it would ground the ignition just enough to start then die and finly quit altogether.
just something to check skooter

 

[retoid]

The fuel line is brand new. I checked the impulse line again, no cracks or hairline fractures visible.

Here is how it ran last before taking it apart.
[video=youtube;WLHPFBU5sxk]http://www.youtube.com/watch?v=WLHPFBU5sxk[/video]

 

[retoid]

not sure if that photo above was showing what you wanted to see?

 

[jimbo1490]

It does unless you are really good........and have tiny, long fingers.:jester:

Or a 6" curved hemostat:wink2:

 

[PA Plumber]

From the vid, I wonder if there is still a carb problem/air leak somewhere.