Latest acquisition: 041 Farm Boss

I just picked this up from CL, an extremely clean (under the dirt) 041 Farm Boss. This is a generation older than the saws I'm most familiar with, so I'll probably have a few questions.

I was told that it had been on the shelf for a couple of years after the guy I bought it from straight-gassed it in a moment of forgetfulness. He claimed the piston and/or cylinder was scored and has vague memories of having seen the scoring, but can't remember how he would have seen the scoring and says he never took it apart. He concluded that he must have looked through the spark plug hole, but I'm not sure how much he would see that way. BUT, the old gas I poured out of the tank didn't look like straight gas, and the compression feels great. So far the only thing I'm sure is wrong is that the clutch shoes lost their friction material, which I found wedged in-between the shoes and drum so that the engine was no longer isolated from the sprocket.

I haven't had time to take a serious crack at getting it started yet, but felt like showing it off a bit. Came with a good chain and the original (worn) bar, which I'd removed to investigate the clutch before I took these pics.

 

A number of our members here still routinely run those old gems. I replaced the oil pump in a neighbor's too, first and only one I ever worked on. OLD gas can look quite funky so its hard to tell if it was "straight" or not from your description, but if it was only "deep shades of yellow/amber" it probably was. You should not have any trouble finding parts for it. My neighbor had picked up a "parts" one years ago so we just took the oil pump out of that one. Ran great swapped into the other machine.

 

The gas was dark gray, not just amber.

Looking on eBay, I'm seeing at least two different styles of clutch advertised for the 041. Some have the friction material on the shoes, and some are solid metal like modern clutches. Does anyone know whether they're interchangeable?

 

Had time to check it a bit more, and it still doesn't look like straight gassing. Compression is 160, and I can't see any scoring through the spark plug hole, which makes me think the seller talked himself into seeing something that wasn't there.

It's not running yet, apparently due to an ignition problem of some sort. I removed the plug from the cylinder, reconnected the lead, grounded the plug and pulled the cord several times, and only saw one (quite fat and healthy) spark. That gives me a direction to head in, at least. I haven't even figured out how to get the recoil cover off yet.

 

It is an old gem. I have my dads he bought new. They have an awesome old school rumble.

160 is a strong saw. Worth some bucks or horse trading to get it running.

Ill add some pics of mine when i get a chance.

 

I suspect you're right. I haven't messed with ignition points since I got rid of my 1975 Honda CB750, but that would neatly explain the intermittent spark. Hopefully I'll have time to get into it tomorrow.

 

Sweet old saw .Hope to a see a pic of it working sometime soon

 

When I get that far I'll post video.

 

Jon I have one as my primary bucking saw. Really torquey saws, slower than the new stuff but they can grunt through cuts.
You might want to try another plug on your spark test and check the cutoff switch before pulling the recoil and tank half. The points are actually pretty reliable on these saws

 

I cleaned off the crud yesterday afternoon, and in the process did a few more experiments. Changing to a new plug didn't help anything, and neither did disconnecting the kill switch wire from the switch. I couldn't locate my one piece of emery cloth, so I used a sheet of 400 grit silicon carbide paper to clean up the points. The first pass pulled out a streak of carbon, but otherwise the points look pretty clean. After putting it back together I decided to "take one for the team" and bridge the plug gap with my fingertip while pulling the starter. Turns out the spark is weak rather than intermittent; the voltage is there, just not enough to jump the gap. So I guess it's down to either the coil or the condenser. If anyone has a method or can point me to a flowchart for diagnosing which is the problem, I'd appreciate it.

I also found that almost half the fins on the flywheel are broken off, so it will vibrate badly if I do get it started. Fortunately I paid little enough for the saw that I can afford to put some money into parts.

 

More experiments, and the problem seems to be getting clearer. I found this Fluke guide to diagnosing magneto ignition problems, and methodically worked through it enough to establish that the condenser is probably good. My meter shows no continuity at all (O.L on ohmmeter setting) through the coil on secondary side, so my best guess at this point is that the coil is shot. I even removed the plug wire and tested right at the terminal on the coil. I also noticed that the kill switch works most of the time but is a little erratic. I don't understand the electronics well enough to guess whether a failing kill switch could kill the coil. Anyone know whether this is plausible?

 

You might consider converting it to electronic ignition. The "FixingStihl" guy on ebay does conversions for old stihls like this. I bought one of his 031AV services once (you send him your coil and flywheel and he alters the coil and sends back an electronic flywheel with it). My saw ran like no other 031 I ever saw, and I've owned 6 of them. He is offering a service for the Bosch type ignition on many 041AV for $80. Not cheap, but if you don't have much into the saw anyway, this might be a way to go. He guarantees his work too. Check it out!

http://www.ebay.com/itm/STIHL-041AV...178725972?pt=US_Chainsaws&hash=item3a7b6b3254

 

Better get another list of needed parts over to me... I'm pretty sure there's an 041 carcass in that barn haha.

 

I saw that, but the price is a bit daunting since I also need a clutch and flywheel.

 

Heh. I already ordered the clutch on eBay, but otherwise it's looking like coil, kill switch and flywheel.

 

On the other hand, it looks like these coils are kinda expensive / hard to come by, too.

 

That's just what I was thinking too. It may not be that expensive after all to go the electronic route when you add up all your other costs. A parts saw is a real good way to go too. Sometimes you can get one of those cheap on the bay, then you will have a host of parts for down the road service.

 

Well, it'll need a flywheel regardless of whether I convert it.

Here's what it looks like cleaned up. It would be a shame not to fix it one way or another.