028 AV Super won't start

[alb0ndigas]

Hi I am new to the forum. I bought a used Stihl 028 AV Super and have not able to start it. So far I cleaned the ignitor and reset the gap for it and the plug. I am getting good spark but still it just turns and turns without even a pop. I think I am getting gas because I can smell it after a few pulls. The air filter is clean and the exhaust looks fine too. The saw came from Portland and I bought it here in Las Cruces NM which is at a much higher altitude. A friend said maybe it needs high altitude jets in the carburetor. The guy I bought it from said it was running when he left Portland. Any help would be Appreciated.

sincerely,

Stihl not running

 

[Mad Professor]

Put a thimble full of mix in the carb and try it again.

If it fires check carb, fuel line/filter, and vacuum leaks (intake boot/impulse line/crank seals). Start with carb and fuel line, if they check out O.K. may want to get a vacuum/pressure test to pinpoint possible air leaks.

Edit: 1) there is a vent for the fuel tank, check that that is not plugged

2) No need for new jets, carb can be leaned by turning in hi/lo screws clockwise. Do a search on this, too lean will cause problems, a good place to start is 1 turn out from fully seated.

 

[rocky226]

:agree2:

Put a thimble full of mix in the carb and try it again.

If it fires check carb, fuel line/filter, and vacuum leaks (intake boot/impulse line/crank seals). Start with carb and fuel line, if they check out O.K. may want to get a vacuum/pressure test to pinpoint possible air leaks.

:agree2: That's exactly where I would start.

 

[alb0ndigas]

thanks

checking it out, stihl checking it out.

Thanks for the input, I'll get back to yous guys with results.

 

[rmh3481]

Chances are if you have spark, fuel and compression your going to get something. Pull the spark plug out and then pull the engine over slowly with the starter handle. Try to keep your thumb over the plug hole threads as you pull it over. IF you can keep your thumb over the hole keeping the compression inside the cylinder that the rings are worn. If you have a gauge, your going to need 100psi for the engine to run.

The other thing that I see once in a while with an older engine is that as an ignition wears it will not fire a resistor spark plug. A resistor plug is one that is designed to only fire above a pre-determined voltage. These R plugs give a real hot spark for lower emissions but sometimes the older ignitions just wont fire them. Try a regular CJ6 or CJ7 plug and see what happens.

Here is also a link to an Illustrated Parts listing and some details about your saw at Mike Acres Site. The manual is in PDF form and all you need to see it is to click it and allow it to load. http://www.acresinternet.com/cscc.n...5f352eae1aecdc9288256ba20048eb6b?OpenDocument

Its one of these things that your going to have to start at the beginning and work your way through ruling out possibilities as you go. Check the fuel lines and impulse lines for cracks. Check for spark and compression and so on. The only other thing that sometimes happens is the engine will skip time because the flywheel isnt in the right position. Check this by removing the flywheel and making sure that the key is present.

Good luck with best wishes,
Bob