Ever had this problem?

[andrethegiant70]

So the 041 is acting up.... I went to start it up and could hardly even pull the pull cord... odd since it has been running great. It felt smooth, mind you, but it felt like I had WAY too much compression. On the third try (after I had about dislocated my my elbow) I decided something was horrendously wrong and I pulled the plug.. out poured a gout of mix! I reinstalled the plug, got one easy pull out of it (didn't start) and then the same thing happened, the chamber fouled with mix and compression went through the roof.

Here's what I'm thinking... for whatever reason, I think my crankcase is flooding while the saw is sitting around, and since the 041 has a horizontal piston, it floods the combustion chamber if it sits long enough. I DID get the saw started, but only after I decided that it HAD to start on the first pull, which I accomplished with a little help from some starting fluid. It smoked like crazy, ran rich for a minute, then ran like a champ.

Maybe air expanding in the gas tank on a warm day can force fuel into the crankcase through the carburator or even the impulse line?

Does any of this sound familiar to anyone? If so, what in the world was the problem and the solution?

 

[Lawn Masters]

On my dolmar when I had the 120Si, it would do that, especially if you left the choke lever open for awhile. could be a leaking gasket in the carb causing this.

 

[TonyM]

A leaking needle and seat will cause that to happen. Pressure builds in the tank and pushes fuel past the needle. Try leaving it sit with the gas cap a little loose once and see if it still happens. A carb kit, or at least cleaning, may be in order.

 

[cbfarmall]

I've had that happen three times: twice it was the carb needle leaking from an improperly set lever, once it was because bar oil got in the crankcase.

Chris B.

 

[Dan Forsh]

Maybe I'm wide of the mark, but one of the 1st problems the guys on here helped me with sounded pretty similar to this, ignoring the fuel excess, have you checked that the pulley isn't cracked allowing the starter cord to over wrap itself?

 

[andrethegiant70]

Hi, Dan, I actually followed that whole discussion (I lead a charmed life) and would have contributed but I was as confounded as you were.

I think these fellows have nailed it.. I thought it might be a starter problem until I pulled the plug and the saw spun happily... heck, I was worried I had seized the thing on that last juniper stump!!

The saw is actually very much beginning to need a new starter rope.. I'm amazed it stood up to the abuse I just gave it seeing as how I just about hurled it across the yard by the starter handle. The wife was probably wondering why I was shot putting with my favorite saw.

 

[stihltech]

oil pump

Are you sure it is mix?
This saw is noted for the pump seals leaking and filling the crankcase with bar oil. New seals in the pump will cure it.
To get it started again, leave the plug out and crank it over, side ways, upside down, any which way you can. Put the plug back in, but don't be suprised if it locks up again. Repeat the process. A little mix in the carb throat will help.
It will start and chase away every bug in your yard. DO NOT start in an enclosed area.

Hope this helps.

 

[andrethegiant70]

Hmmm.. thanks, Stihltech.... no, not really sure its mix. I guess I'll have to take a closer look at the gack that comes out of the plug hole next time.

New pump seals, eh? Would that be an enterprising amateur job or a pro-only job? I haven't dissected that part of the saw yet.

 

[Stihl 041 super]

compression

hey My 041 Super does that a bit too but it always has arm snapping compression even when hot.

 

[GASoline71]

New pump seals, eh? Would that be an enterprising amateur job or a pro-only job? I haven't dissected that part of the saw yet.

Andre, I just ripped the oil pump out of two 041's tonight and the seals in both pump housings were shot. There was a lot of black crap in the pump housing and I'm assuming that is what was making the saw smoke during the first bit of use (leaking into the case). Then the smoke would clear after the crankcase probably cleared itself out during normal warm up during a cuttin' session. Search the boards and you will find a post that stihltech did about taking out the pump and checking the seals and spring. It is located in front of the saw behind the dog, and is held in with a snap-ring.

Good luck , Gary

 

[GASoline71]

cleaning out the pump housing

Now that I have the pumps out of the cases and they are all gunked up inside.... what can a fella do to clean this area out without taking the cases apart? can you spray it with a contact cleaner such as brake or carb cleaner? I have a spray electrical terminal cleaner that doesn't seem to be as corrosive as the latter. Any ideas?

Gary