041AV replacement cylinder is 48mm!!

[cantrma]

My extended family has been in the sawmill business in West TN for 4 generations. I have an older 041 (late 60's) and 041AV that we had back when I was in high school and that was 37 years ago. I just resurrected them, pretty easily, but both developed problems after just a few days. Most were easy. The 041 has almost no spark, it will twinge you pretty sharp but won't fire a plug. Points type, ideas for troubleshooting would be nice. Looks like I would need a junk flywheel I could cut the center out of to adjust the timing?

This thread is about the 041AV. It wouldn't start cold without ether but ran OK, maybe a little weak, and started hot first pull every time. I bought a piston and cylinder kit off of eBay that said 041AV - 48mm cylinder and piston. Part number was 1110 020 1203. It came in, was obviously new old stock and I was happy. Until I pulled the cylinder while ago and it was 44mm. I checked a base gasket, the cylinder would bolt up just fine. The questions are is the wrist pin the same, will the housing fit around it, and will the intake manifold and muffler bolt up? I guess what I'm asking is did I buy the wrong and unusable part or is there a hop-up kit (stihl branded) for this saw and I got it?

Finally, there was a lot of slop in the big end bearing. It slid up and down the crankshaft maybe 1/4" but it also rocked on the big end bearing another 1/4" at the end of the rod. Just the cylinder and piston have me as far into (or further) than a practical man would go, even I wouldn't split the case on it. Reckon I could get a couple years of occaisonal use out of it before the bottom end came apart?

Kicker after all this is the cylinder looks pretty good. They piston has a score down the side of the ports, not awful but not the end of the world either. I'll probably just try to find a piston and rings if the cylinder doesn't fit this saw.

Thanks,
Mark Cantrell

 

[Cut4fun]

Just guessing, but looks like you bought the 041AVE SUPER 48mm topend kit, 3rd one down on list. the rest were 44mm going by acres site.
http://www.acresinternet.com/cscc.n...95870e172008295c88256ba20018167b?OpenDocument
http://www.acresinternet.com/cscc.n...cf7d40759681b4bf88256c1c0016a801?OpenDocument
http://www.acresinternet.com/cscc.n...5a0c2feeba92ec1088256ba20048d67c?OpenDocument
http://www.acresinternet.com/cscc.n...debc625f5d16dd1e88256dee001f917a?OpenDocument

 

[cantrma]

Wow, I'm impressed. New to the site and shocked I got a resopnse that quick. Question now is can you use the AVE Super piston/cylinder on an 041AV?

 

[Cut4fun]

Lakeside, Thall, Alsmith and others will have to get with you on that 041 swap. I know nothing about that saw. Good luck

 

[Trigger-Time]

One thing, 041 Super uses long cyl. bolts (studs)


Pic of stud bolts

 

[Four Paws]

I am going to jump in this thread because I am just going through a 041 Farmboss for a friend of mine. His saw needed a tune-up (carb kit, plug, impulse hose, etc.) and when trying to start it, the dang thing would kick so hard that would jerk the rope right out of my hand. I immediately knew it had to have a problem with the timing. Pulled the flywheel and found a broken key...so, the problem is identified.

Questions:

1) Is the flywheel key a common size - available at a hardware store?

2) In regards to timing, what is the 'edge gap' that Acres site references in the link above?

 

[Trigger-Time]

I am going to jump in this thread because I am just going through a 041 Farmboss for a friend of mine. His saw needed a tune-up (carb kit, plug, impulse hose, etc.) and when trying to start it, the dang thing would kick so hard that would jerk the rope right out of my hand. I immediately knew it had to have a problem with the timing. Pulled the flywheel and found a broken key...so, the problem is identified.

Questions:

1) Is the flywheel key a common size - available at a hardware store?

2) In regards to timing, what is the 'edge gap' that Acres site references in the link above?

041 info...........See Lakeside's post #21 & #23, download info.....it's worth your time

Follow link..... http://www.arboristsite.com/showthread.php?t=44651&page=2

In this link see Lake's post #8 for years of 041 saws...http://www.arboristsite.com/showthread.php?t=45072

 

[JohnO]

The 041 Super uses a different carb. Better check that out before you get too far along on the swap.

-John

 

[Lakeside53]

I am going to jump in this thread because I am just going through a 041 Farmboss for a friend of mine. His saw needed a tune-up (carb kit, plug, impulse hose, etc.) and when trying to start it, the dang thing would kick so hard that would jerk the rope right out of my hand. I immediately knew it had to have a problem with the timing. Pulled the flywheel and found a broken key...so, the problem is identified.

Questions:

1) Is the flywheel key a common size - available at a hardware store?

2) In regards to timing, what is the 'edge gap' that Acres site references in the link above?

No, you won't find the key in any USA hardware store.. Just buy it from a stihl dealer.. really inexpensive..


Edge gap is a term refered to in the service manual about the magneto timing... Did the pages I uploaded a while back cover that?

http://www.arboristsite.com/showthread.php?t=44651


posts 21 and 23

 

[Four Paws]

Thanks for searching for my NOOOBIE arse.

That was some fantastic information that is sure to help me. This is only the 2nd stihl I have fixed for someone...I must say I like the design and build quality of the 041 far more than that of the MS210. The saw I am working on had the crank replaced by a dealer, who must have smashed the key while tightening the flywheel (with an impact I am assuming due to the way the key was folded over before it sheared). It now fires before TDC and rips the rope through your fingers - I am sure it is just as hard on the recoil and internal bearings as it is on my hands.

Anyhow, I'll post up some pictures when I get it back together...the saw is pretty clean for 30 years old.

 

[Patrick62]

I can help with the timing issues

If dis-connect the coil so that you can hook a ohm meter across the points it makes things a touch easier.

Now the in depth explanation. Magneto's generate the power at almost the same time it is used. What you are seeking and by looking at the flywheel in repect to the coil is when the magnets are very close to the centered position of the coil, this is when the maximum power is available. Now the fun part. Get this position in relation to the position of the piston. It should be close to TDC. If not just a smirch (exact measurement there) BTDC.

The moment that the points open the coil will fire the plug. With the ohm meter checking the points for you, you can start adjusting the gap until when you turn the flywheel it "opens" at just about the right time. Trial and error. You are curious you can then measure the gap... I prefer just to set it and forget it.

With the ignition connected back up you should find a nice FAT spark at just a touch before TDC. I have timed many a engine this way.

The 041 is a great saw. I ran one for years. I am now falling in love with a 44, but still have fond memories of the 41

-Pat