New to the forum and new to the Farm Boss 041

[McQuade]

Helllo folks! This forum is amazing, stumbled across it while doing researching on the 041. I'm looking for some help/tips/advice. My father passed away back in 2017 and I brought his 041 home with me. I tried to start it when I got home and I couldn't pull the rope. I may be a girl but I'm no wimp and not new to starting and running chainsaws, just new to fixing them. He had been pretty sick for a while and I don't know how long it had been since he had it running. Well a few weeks ago, I decided I should do something with the saw. My stepdad (SD) was a timber faller for around 40 years (used to work with him in the summer and spring break to raise cash for my sports programs when in high school) so I decided to get his advice. I told him I could pull the starter just fine with the spark plug removed. He suggested I remove the muffler and take a look at the piston and ring (it only has one) and to lube it up because it may have dried up over time and that could be making it had to pull or the piston ring could be seized up. I took it apart and noticed that the black fuel line that goes from the crankcase to the carb was broken. Is that what is called the impulse line? I replaced that line. He also suggested I rebuild the carb because the diaphragm could be stiff and would not want to pump fuel very well. I had to replace the carb because I ordered the wrong rebuild kit. I think I have the correct kit (RK-23 HS) for a Tillotson carb on the way. The first kit didn't have the groove on the post of the diaphragm to hook it on the inlet control lever.
The piston ring was not seized and the piston was not scored at all. I replaced the fuel line into the tank because it was pretty rotted and the fuel filter in the tank. I replace the air filter and spark plug. I made sure all the old gasket material was removed and each piece was cleaned prior to reassembly. New gaskets for the muffler and carb matting surfaces.
I backed the H and L carb screws out about a turn each, don't remember exactly. Not a pro with carb adjustments so I just went with what I found on this forum to start with. I got the dang thing running!!!
Now here is the problem and where I need advice. It will not idle down unless the big idle screw is all the way out. Talked to my SD again and he said it is getting too much air from somewhere. More research tells me it could be the crankcase seals but that I should do a vacuum and pressure test first to make sure. I ordered the tool to conduct the test. I'm not really sure how to go about doing the test. I've read to hook into the impulse line, though I'm not really clear on what line that is. I think it is the line that goes from the carb to the top of the crankcase but I'm not positive. Then how much vacuum and pressure do I apply and for how long? I know I need to seal off the muffler and carb ports also. Would one of you happen to have a PDF of a work shop manual for the 041 (not an AV) incase I do have to break it down and replace the seals? I would rather do my own work, it's not out of my wheel house, I'm a fire engine mechanic by trade.
I did find that the fuel cap is cracked but I don't think that is the cause of my problem. I have one on order to replace it.
Tell me what you all think. Am I on the right track here?

Thank you,
Paula

 

[SAWTECH1]

Helllo folks! This forum is amazing, stumbled across it while doing researching on the 041. I'm looking for some help/tips/advice. My father passed away back in 2017 and I brought his 041 home with me. I tried to start it when I got home and I couldn't pull the rope. I may be a girl but I'm no wimp and not new to starting and running chainsaws, just new to fixing them. He had been pretty sick for a while and I don't know how long it had been since he had it running. Well a few weeks ago, I decided I should do something with the saw. My stepdad (SD) was a timber faller for around 40 years (used to work with him in the summer and spring break to raise cash for my sports programs when in high school) so I decided to get his advice. I told him I could pull the starter just fine with the spark plug removed. He suggested I remove the muffler and take a look at the piston and ring (it only has one) and to lube it up because it may have dried up over time and that could be making it had to pull or the piston ring could be seized up. I took it apart and noticed that the black fuel line that goes from the crankcase to the carb was broken. Is that what is called the impulse line? I replaced that line. He also suggested I rebuild the carb because the diaphragm could be stiff and would not want to pump fuel very well. I had to replace the carb because I ordered the wrong rebuild kit. I think I have the correct kit (RK-23 HS) for a Tillotson carb on the way. The first kit didn't have the groove on the post of the diaphragm to hook it on the inlet control lever.
The piston ring was not seized and the piston was not scored at all. I replaced the fuel line into the tank because it was pretty rotted and the fuel filter in the tank. I replace the air filter and spark plug. I made sure all the old gasket material was removed and each piece was cleaned prior to reassembly. New gaskets for the muffler and carb matting surfaces.
I backed the H and L carb screws out about a turn each, don't remember exactly. Not a pro with carb adjustments so I just went with what I found on this forum to start with. I got the dang thing running!!!
Now here is the problem and where I need advice. It will not idle down unless the big idle screw is all the way out. Talked to my SD again and he said it is getting too much air from somewhere. More research tells me it could be the crankcase seals but that I should do a vacuum and pressure test first to make sure. I ordered the tool to conduct the test. I'm not really sure how to go about doing the test. I've read to hook into the impulse line, though I'm not really clear on what line that is. I think it is the line that goes from the carb to the top of the crankcase but I'm not positive. Then how much vacuum and pressure do I apply and for how long? I know I need to seal off the muffler and carb ports also. Would one of you happen to have a PDF of a work shop manual for the 041 (not an AV) incase I do have to break it down and replace the seals? I would rather do my own work, it's not out of my wheel house, I'm a fire engine mechanic by trade.
I did find that the fuel cap is cracked but I don't think that is the cause of my problem. I have one on order to replace it.
Tell me what you all think. Am I on the right track here?

Thank you,
Paula

You are on the right track. pressure /vac test are performed with the carb, and muffler sealed off, and the impulse port should be attached to the head of the saw, it would made out of brass most likely. You will need something to use to find small leaks, soapy water mix in a spray bottle. You will need to remove the starter cover and pto side of the saw. I normally run about 10 psi for about 10 min, and then flip the tester to vac and pull about 10 bar on the gauge, then i rotate the crack to insure the seals are not leaking ,also spray around the head and the ports you have sealed off.

 

[Old2stroke]

It will not idle down unless the big idle screw is all the way out. T

Make sure that it isn't just a case of the throttle linkage holding the throttle partly open. With the idle stop screw backed out, the throttle plate should be completely closed and there should be some free play in the trigger. Also, if the L screw is set too lean, it will produce a higher idle speed but should also bog when accelerating from idle. Finally, if the clutch springs are weak, you could be trying to achieve and unreasonable low speed to stop chain motion.

 

[Patrick62]

congrats on the 041, one heck of a saw.
Yep, likely a leaky seal... pres/vac test it.
We used one up here for many many years. Brian still has it, somewhat repaired after a tree fell on it.
I ended up with one (missed having one around). And mine leaks as well, somewhere.
Have to adjust carb one way to get it to start, and then when it warms up, adjust it back??
Leaks when cold, seals up better when warmed up? Yeah, I will get after it... one of these days.

Oh yea.... no chain brake, no anti-vib. Shake the fillings out of your teeth.
But, for a 60cc saw they are torque monsters.

 

[pioneerguy600]

On te 041`s, both FB and AV have a air leak likelyhood between all the gaskets, spacers and carb , kind of a well known leak area on these saws, best to use new gaskets and make certain all screws are tight, some sort of thread lock is a good idea on these saw also.

 

[hotshot]

The second post of the old thread attached below gives all the possible air leak points. Good luck with the 041 repair, as there can be multiple air leaks.!

I’ve found a lot at the carb/intake manifold stack too, plus at the orange oiler knob shaft & PTO side crank seal. Note that you have to manually hold the oiler gear assembly in with either a custom bushing, or your thumb, (after clutch removal) to properly run the tests.

https://www.arboristsite.com/threads/041-problem-and-theory.261143/

 

[pioneerguy600]

Yes that O ring on the oil pump is another air leak spot most don`t know of as its hidden from view so the pump has to be pulled out to check it.