Stihl 041AV barn find / will it start

[JOEPRO]

Admittedly it's not actually a barn find but that sounds much more interesting than an ebay spares or repair purchase under the influence of alcohol as I plunge ever deeper into the Stihl rabbit hole.

This saw is an early 041av Electronic saw which turned up yesterday and clearly has been laying unused for many years.



The plan is to just see if I can get it running first and us it some on my current tree cutting project at my house.

So last night I determined the engine isn't seized and the new recoil spring supplied was quite useless as it is incorrect and the original wasn't broken anyway.

Replacing the pull cord appears simple in principle but it's the early style friction plate recoil on this saw:



Long story short I got it to turn over a couple of times before the recoil slipped again so I ordered new inexpensive replacement parts from ebay will be here in a few days.

 

[JOEPRO]

When pulling it over it did feel like it has compression. But the ignition tester may not have been sparking.

I believe this is a points type ignition system on these early electronic saws. Have any of our ancient experienced members fettled with these before and can offer advice in that regard?

 

[JOEPRO]

I went back out and continuity tested the kill switch to ensure it was A: working and B: in the correct run position.

The pull starter had a couple more pulls in it and I could verify spark is indeed present

It does feel it it has good compression but after 30 minutes messing with the pull starter I gave up and really should just await the new parts for that before continuing. I will order a carb rebuild kit too as I'm quite sure it will benefit from it .

 

[MickeyW]

I still have that same model tucked away somewhere. It was the first saw my dad bought, used from a farm sale and a sort-of runner. By necessity it became a proper runner on a certain Friday morning in October 1987.
It was a darn good powerful saw, an early model with AV mounts but no chain brake or modern niceties.

 

[zzr1200]

Now't wrong with an Ebay purchase under the influence now and again....

I wish I could find a 090 or 3120 for silly cheap money even blown up.

 

[frank horton]

sooooo much better than their modern efforts......I only buy Japanese machines now due to bad experiences with build qual .......

only ever bought Sthil after a certain SWedish comp got bought out by electrolux....
anyway.....this new machine spent more time in the repair shop than working.....
after theatening them with bad publicity they gave me another new one.......which lasted until one month after the warrenty ended......!!!!!!!!
only Japanese now.....

 

[JOEPRO]

Today I got a couple of hours to work on the old 041av. I helicoiled all 4x stripped out fuel tank/ recoil housing bolts so those are nice and solid now. The rubber AV mount on the handle fell apart in the process so new one on order.

The new recoil inner lining and friction plate have fixed the recoil. So I was able to do a compression test and it's 145psi. Very strong for an old saw that appears to have its original cylinder. These things must run forever




The carb rebuild kit should be here tomorrow it's very slow postage. So in a few days I hope to be able to try and start the old girl. With compression and spark it should run.

 

[Turbo]

Check for wear in the main crank bearings. We had an 020av, fabulous saw that I was using at 12 years old! It got to be that you couldn't get it to run properly, dealer diagnosed terminal side bearing wear, common in those saws.

 

[awemawson]

Have you checked for crank case leakage at the crankshaft seals?

 

[JOEPRO]

Check for wear in the main crank bearings. We had an 020av, fabulous saw that I was using at 12 years old! It got to be that you couldn't get it to run properly, dealer diagnosed terminal side bearing wear, common in those saws.

Have you checked for crank case leakage at the crankshaft seals?

I checked the crank for any play and it's good. Bearings feel healthy and tight.

Whilst I have not pressure or vacuum tested the crank oil seals I don't expect there to be any issues in that regard. To do that properly I'd need to remove the exhaust etc and for now I just want to see will it fire up and run.

 

[JOEPRO]

So unfortunately the 041 is not a runner. I got the carb rebuilt and back on it with new fuel lines. It fired off once on choke and nothing after that despite trying for 10 mins or so.

Adding fuel directly into the carb intake made zero difference so I don't think it's a fuel problem.

Whilst I have spark, it does look very weak. A faint yellow spark in the tester. Normally on other saws it lights up bright orange.

So I suspect a weak spark /i gnition problem which is perhaps the reason why the saw was laid up for so long.

I have ordered a crank pulley removal tool for this saw so I'll see what is behind there ignition wise and I've started researching this. Seems like a bit of a minefield of discontinued parts but will see as I'd like to get the saw running.

 

[JOEPRO]

I got the flywheel puller in the post and can now see the ignition system






No idea what I am looking at. Lots of research ahead!

 

[redlig]

I went back out and continuity tested the kill switch to ensure it was A: working and B: in the correct run position.

The pull starter had a couple more pulls in it and I could verify spark is indeed present

It does feel it it has good compression but after 30 minutes messing with the pull starter I gave up and really should just await the new parts for that before continuing. I will order a carb rebuild kit too as I'm quite sure it will benefit from it .

View attachment 460144
View attachment 460145

A squirt or two of Acetone will usually tell you if there is life .Remove air filter and squirt directly into carb never fails . Don't try to get it to run for any more than a few seconds as ,obviously there is no lubricant. re spark colour remember : Red is dead Blue will do and white is right.

 

[Turbo]

I think our 020 was one of the first stihl saws with electronic ignition but it was unreliable.

Initial symptoms were not starting again after refuelling then eventually not starting at all.

The unit was replaced a few times until a revised version was fitted that cured the problem.

By now there's probably a modern replacement for what's under that flywheel.

 

[Migmac]

For testing spark get trillium spark check’r, I’ve seen a few guys using them. Great bits of kit.

 

[JOEPRO]

I was up at 6am this morning to take some more of this saw apart before work!

The short version is my 041 has an early euro Bosch electronic ignition system. It has an ignition module near the air cleaner. Condensor but no points.

This is a rare system and there are no spare parts available for it. I fact it's so rare I downloaded several service manuals and it's not listed.

There was a wire which was very weak and corroded at the ignition coil itself where it enters it.




So I went ahead and ordered a new aftermarket electronic ignition system from Saegenspezi In Germany whih is made especially for the 041. For use with points system. (Their version for Bosch electronic ignition systems says except condensor) So I also bought a good used points version 041 flywheel to make this upgrade.

I will have the parts in a week or so, after that it should have a replacement ignition system and ready to try again!