028 super av problems

[JJohnstone_]

I have an stihl 028 av super , and it idles good and runs when you ain’t cutting, as soon as you put it into the wood and give it full throttle it dies? Anyone know what it could be?

[Muddy42]

I'm sure the experts will be along to comment.

Have you changed the spark plug/cleaned the air filter, that fixes a lot of issues for me?

Has someone messed with the tuning H screw badly or are they at the default setting?

Or it could be a crack in a fuel or air line somewhere, giving the wrong mix

 

[spudulike]

Sounds like fuel starvation. Fit a new fuel line and fuel filter if not done in the last few years, strip the carb, check the gauze strainer for blockage. Reset the screws H and L to one turn out from fully in and see how it goes.

Pulling off the exhaust and checking out the piston is a good idea.

[peatff]

I had a 180 with similar symptoms and it was a metering problem.

[JJohnstone_]

Thanks for the advice guys when I get a look I’ll be sure to post and let use know what it was!

[pleasant]

Agree with Spudulike. If you are confident enough, once you have checked fuel lines start it up, get it warm and put it under load in some wood- if it loses power and dies, take it out the cut and give the H screw a quarter turn anti clockwise (this will richen it up a bit at top end- then re try in the same cut. It will either be the same -in which case do more in depth checks as mentioned above, or it will improve things- in which case a carb clean/new diaphragms may well be in order, or it will cure the issue.