Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: R.Singletary on June 09, 2014, 09:42:29 pm


Title: high idles then dies...
Post by: R.Singletary on June 09, 2014, 09:42:29 pm
Hello, i have a stihl 051 av, when i start it, it idles ok, but then it takes off and high idle  for about 10 seconds then dies. I have tryed to ajust the carb and it still dose it. i think its an air leak, but not sure where. i really want to get this saw running, but not too use, its too big and its a classic...HELP....
Title: Re: high idles then dies...
Post by: aclarke on June 09, 2014, 10:01:55 pm
Check the fuel vent first
Title: Re: high idles then dies...
Post by: R.Singletary on June 09, 2014, 10:16:21 pm
How would i do that and where is it on a stihl? is it in the same place as on a husky? in the fule tank?
Title: Re: high idles then dies...
Post by: RoyM on June 09, 2014, 10:54:31 pm
Near as I remember, the tank vent is a short piece of tubing with a screw in it sticking out of the tank. The lay downs suffered from air leaks around the intake gaskets. Also make sure the insulator block is not ****.
Title: Re: high idles then dies...
Post by: Fish on June 10, 2014, 03:40:40 pm
Go through the fuel system correctly, that old beast deserves to be fixed correctly!!!

Pull and rebuild the carb, check all hoses, connections, gaskets on all of the blocks between the carb and block, impulse.
But before buying anything, after you have the carb off, go ahead and pull the muffler and look at your piston condition, that will
tell you your next step.
When you have the carb apart, you will likely see a wad of snuff in the screen, that would be the remains of your fuel filter insert,
so you will need a new fuel filter, remove the spring/lever/needle, and hold the bare carb body up to a light and peek through that passage, then blow it out with some air, then look again, and visually verify that it is clear, then blow out the other crud, and rebuild with a new kit.

Looking for air leaks is one of the last things to be doing..........
Title: Re: high idles then dies...
Post by: R.Singletary on June 12, 2014, 10:02:14 pm
Hello, i would like to thank aclarke,Roym and Fish...thank you so much for the imput. I will kit the carb in a couple of week and let the forum know how it goes. In the mean time, i did pull the carb apart and the screen did have white residue . i blew it clean with air and then pulled the needle and made sure there was blockage, then looked thru it for a visual. then i put it back together. thats when it started the high idle. Thank you for your help. i will update in a couple of  weeks....
Title: Re: high idles then dies...
Post by: Oliver1655 on December 01, 2014, 11:00:41 pm
To clarify Roy's post.  The screw/set screw in the tubing style of vent is pushed in about 3-4 threads, NOT screwed in.  If it is screwed in  the treads will cut into the tubing creating a seal loosing the venting ability.  I found this out the hard way on my 08s.
Title: Re: high idles then dies...
Post by: 660magnum on December 01, 2014, 11:04:56 pm
After making my new vent, I checked it with the MityVac for proper operation. It was A-OK