Stihl av28 wood boss dies after 5 minutes

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ba_50

ArboristSite Member
Joined
Mar 5, 2007
Messages
52
Reaction score
0
Location
Illinois
It has a new carb, fuel line and fuel filter, plug. One crank seal was replaced. What is most likely fix? Head gasket, other crank seal?
Thanks
 
With it running that long I'd be looking at either low compression or a plugged tank vent. Does it restart when it dies? Eliminate the tank vent by pulling it off and running the saw. It's a grub screw/screw setup. Do you have a compression gauge? A failing ignition could also give you those symptoms.

Untitled.jpg
 
It will run for 5 minutes and then starts bogging down. Take it off the log it speeds up again. Leave it on the log and it will die. The vent hose was new but I took it off anyway. Same result. The compression is ok.
It has never had anything electrical done to it.
It will restart but not easily.
 
Can you provide the compression number? If it’s above 130 it should be okay, though not great. Might also check the muffler. Spark screen might be clogged,or the muffler itself is clogged. Other than that have you adjusted the high needle on the carb?
 
2 Stroke engines (scavenging) need the back pressure. The 2 stroke engines expel burnt gas while during intake of fresh gas. Without the back pressure the engine will not run correctly.
 
It will run for 5 minutes and then starts bogging down. Take it off the log it speeds up again. Leave it on the log and it will die. The vent hose was new but I took it off anyway. Same result. The compression is ok.
It has never had anything electrical done to it.
It will restart but not easily.
Does it idle differently on its side? If so it could be crank seals or your cylinder head bolts loose, sucking air.
 
Does it idle differently on its side? If so it could be crank seals or your cylinder head bolts loose, sucking air.
When I say idle differently, usually they will fast idle on one side and die on the other. If that’s the case you may want to pressure test the cylinder/case, or have the stihl dealer do it for you, if you can’t find anything obvious.
 
Can't remember for sure, but don't believe it idled right on it's side.
The muffler bolt holes wouldn't hold it.
I have heard of husky. Husqvarna isn't that great but none of them are.
 
It could also be that the carb wasn’t put together correctly. On the diaphragm side there’s a spacer it that’s on the wrong side of the diaphragm or the little tabs don’t line up, that could be your cause. If it’s a China carb, good chance it’s crap right out the box. Ive has them start and run for a while, frustrating as hell.
 
Back
Top