Stihl 041 Rebuilt - Running too rich

[Vintage Engine Repairs]

Hey mate I have said it already, you just sitting there rev’ing it without load is going to cause all sorts of problems. It will foul the plug like it is, it will cause oil to go everywhere like it is, you’ll get unburnt mix from the muffler, it will wet the plug and cause ignition issues which it is. 2 strokes can’t be sitting there idling…

pulling the plug during this time is a waste of time… you are causing your own problems by ignoring what I have said about letting the saw sit there while you pull the trigger and rev it out the wood. It will never be able to be tuned correctly because it’s full of unburnt mix, the saw isn’t hot enough, there is pooling in the crank.

 

[Patrick1903]

Hey mate I have said it already, you just sitting there rev’ing it without load is going to cause all sorts of problems. It will foul the plug like it is, it will cause oil to go everywhere like it is, you’ll get unburnt mix from the muffler, it will wet the plug and cause ignition issues which it is. 2 strokes can’t be sitting there idling…

pulling the plug during this time is a waste of time… you are causing your own problems by ignoring what I have said about letting the saw sit there while you pull the trigger and rev it out the wood. It will never be able to be tuned correctly because it’s full of unburnt mix, the saw isn’t hot enough, there is pooling in the crank.

Unfortunately I wasn’t in the woods today. The thing is, none of my other saws eat spark plugs the way this one does, warming the saw up for 5 mins. Or outright die the way this one does. So my adjusting of the carb was more to get the thing idling to an acceptable level so I can run the saw at all. And to check the operation of the original carb that I put back on there today.

 

[Vintage Engine Repairs]

All saws run differently. Also, 5 mins of idling is one thing, then tuning, then idling then zipping the throttle more tweaking etc. Then you leave it in the shed, pull it out in a weeks time after repairing something or swapping carbs on the saw and repeat it over and over - you are compounding your issue. It will never run right. It needs load; a lot of it and to be tuned while it’s fully heat soaked. That can take 5 mins of cutting or more on a cold day, quick adjustment of the carb (3-4 seconds) then back in the log. I’m telling you this because I have been there, I know what happens and the resulting issues, better to learn from my mistakes!

 

[KASH]

The orange oiler knob is a bit tricky .Turned clock wise increases oil counter clock wise decreases oil you have 1 and 3/4 turns of adjustment .Do not turn the knob all the way down and run your saw.
I am doing the same thing as You with my 041 I think your clutch problem was there are two styles of oiler drive cover washers one has the spacer washer built into the cover washer and you do not use the spacer was on the needle bearing also the drive pins are different lengths.
Kash

 

[Patrick1903]

The orange oiler knob is a bit tricky .Turned clock wise increases oil counter clock wise decreases oil you have 1 and 3/4 turns of adjustment .Do not turn the knob all the way down and run your saw.
I am doing the same thing as You with my 041 I think your clutch problem was there are two styles of oiler drive cover washers one has the spacer washer built into the cover washer and you do not use the spacer was on the needle bearing also the drive pins are different lengths.
Kash

Thanks. Glad to have the clutch issue resolved. I’ve read here and other sites over oiling can happen on these saws.pooling oil, oil on boots, pants covered in oil spray. The oiler knob appears to rotate the correct number of turns, I have it backed all the way to min. I’ve seen some references to the oil tank being pressurized due to leaking seals. Lots of issues with the o-ring and grommet on the oil pump. So figured I’d start by replacing those. Who knows if they’ve ever been done and the saw is 46 years old. I thought it odd the color of the oil coming off the bar. It looked dirty. When I dumped the remaining bar oil from the tank before pulling the pump, it was perfectly clean in the reservoir. So definitely wasn’t getting dirty in the reservoir.

Ultimately I should likely pressure and vacuum test the saw again. I did that before I replaced the top end last year, and I recall it being ok, but maybe I missed something.
Next step for me is to refresh the oil pump and then get the saw into some wood, heated up like Tom says, and tune it. If it still has the hard die problem after that, I’ll report it here and do some more testing.

 

[hotshot]

Whatever happened with your bar oil fix on this 041 Stihl?

It appears to need split apart & the crankcase gasket replaced. Only way to tell is to get a pressure/vacuum tester on it & then bubble test the oil fill cap vent hole.

After you replace the two tiny orings on the oil pump shaft, of course!

 

[Patrick1903]

Whatever happened with your bar oil fix on this 041 Stihl?

It appears to need split apart & the crankcase gasket replaced. Only way to tell is to get a pressure/vacuum tester on it & then bubble test the oil fill cap vent hole.

After you replace the two tiny orings on the oil pump shaft, of course!

Hi, thanks for the reminder. I've thought several times I need to update this thread... So I replaced the o-ring on the oiler, and the seal where the pump inserts into the front of the saw. That seems to have resolved my problems. The saw would not run more than 10-15 minutes without fouling a plug and dying. That appears to be resolved since I've run a few tanks of fuel through it. It also seems to oil normally now. Not sure if pressure was escaping into the oil resevoir and causing the over oiling, and if oil was escaping into the crankcase and causing oil fouling of plug. So I'm in good shape.. Many thanks to everyone who assisted with this...especially @Vintage Engine Repairs with helping me sort out the points ignition. I was shocked the ignition fired properly after reassembling - I was sure I would have to adjust but it seems good.

 

[hotshot]

Good deal on the fix & update.

Oil escapes into the crankcase & gets burned.

I bet if you pull the clutch & pump drive gear out, then look down in at the PTO bearing, it will be all caked up with carbon. Best to clean that crud out.

I just did that yesterday, but split the cases & put in new bearings as it was nasty & had ruined the bearings.

 

[Patrick1903]

Good deal on the fix & update.

Oil escapes into the crankcase & gets burned.

I bet if you pull the clutch & pump drive gear out, then look down in at the PTO bearing, it will be all caked up with carbon. Best to clean that crud out.

I just did that yesterday, but split the cases & put in new bearings as it was nasty & had ruined the bearings.

Wow, very cool. Not sure I had it in me to split the case. Maybe if the saw gives me problems down the road and I want to do a total rebuild. So in your first picture, is that the slot in the case for the oiler? I’m having a hard time picturing how the oiler works. The worm gear rotates the oil pump piston, compresses via the pressure against the oiler control bolt (as the uneven end of piston increases and decreases compression on piston,ie moves back and forth), and forces oil through the holes in the oiler body (from the pickup, straight through to exit the case at the oiler hole at the bar? But how is the oil drawn up through the oil hose from bottom of tank.

I did notice carbon when I pulled the worm gear a long while back. But I wouldn’t have seen the bearing at that point, would I have? Shouldn’t there be a crank seal in there? I need to pull this thing back apart to remember what it looks like! .

Here a pic of the carbon I scraped off the oiler piston where it meets the worm gear. See all the carbon I scraped off. And the entire oiler assembly.

 

[Patrick1903]

Good deal on the fix & update.

Oil escapes into the crankcase & gets burned.

I bet if you pull the clutch & pump drive gear out, then look down in at the PTO bearing, it will be all caked up with carbon. Best to clean that crud out.

I just did that yesterday, but split the cases & put in new bearings as it was nasty & had ruined the bearings.

Wow, very cool. Not sure I had it in me to split the case. Maybe if the saw gives me problems down the road and I want to do a total rebuild. So in your first picture, is that the slot in the case for the oiler? I’m having a hard time picturing how the oiler works. The worm gear rotates the oil pump piston, compresses via the pressure against the oiler control bolt (as the uneven end of piston increases and decreases compression on piston,ie moves back and forth), and forces oil through the holes in the oiler body (from the pickup, straight through to exit the case at the oiler hole at the bar? But how is the oil drawn up through the oil hose from bottom of tank.

I did notice carbon when I pulled the worm gear a long while back. But I wouldn’t have seen the bearing at that point, would I have? Shouldn’t there be a crank seal in there? I need to pull this thing back apart to remember what it looks like! .

Here a pic of the carbon I scraped off the oiler piston where it meets the worm gear. See all the carbon I scraped off. And the entire oiler assembly

 

[hotshot]

Yup, you were looking right at the PTO side bearing when you pulled the worm gear out. The “slot“ is for the oiler shaft end & gears to get lubed from the fuel mix, don’t see that very often.

The oiler adjustment works by changing the plunger rod stroke where the adjuster ball on the control bolt meets the angled cam face on the rod end.

The crank seals on the midget sized worm gear’s inner seal, then the worm gear seals on the outer large seal in the case, which are usually leaking air badly after 50 years, lol.

Go to the beg for manuals thread & see if you can get a copy of the service manual.

 

[stihltech]

The common repair on the 041 pump was disassemble, clean, clean the oring recess with a file ( clean, not file down), replace the oring, spring and rubber bushing between the case and pump. Reassemble with bushing well lubricated. Take your time. Don't forget the internal case ring. And if it had locked up due to oil in the cylinder, pull the plug, pump it out of the cylinder and hope it starts it a couple of pulls. If not, pull plug and pump oil out again. Wrecked my wrist trying to start after an oil pump leak. Then let it fog for 5 minutes. Problem solved

 

[Patrick1903]

The common repair on the 041 pump was disassemble, clean, clean the oring recess with a file ( clean, not file down), replace the oring, spring and rubber bushing between the case and pump. Reassemble with bushing well lubricated. Take your time. Don't forget the internal case ring. And if it had locked up due to oil in the cylinder, pull the plug, pump it out of the cylinder and hope it starts it a couple of pulls. If not, pull plug and pump oil out again. Wrecked my wrist trying to start after an oil pump leak. Then let it fog for 5 minutes. Problem solved

So maybe my oil leak was smaller than yours, if it allowed me to start the saw, but then died 15 minutes later from fouling.

I did have a hard time getting the new/replacement bushing in place when inserting it. I couldn't get it pushed far enough in to get the circlip to seat properly. Had a heck of a time with that. Not sure if there was a difference b/w the proline one and the OEM size wise. Or if I was not doing it right. I need to double check the circlip - to make sure it stayed in. The saw is back to my father in law, who was really happy to have the saw back and told me it now ran like it did when he first got it 45 years ago. I was happy to be able to help him out - thanks to people's help on this site.