Stihl 041AV won't start

[sirreal12]

Hello everyone, I am new to this forum and having read a lot on it I can see there are many folks who are very knowledgeable on the chainsaw I have...ie STIHL 041AV. I bought this saw new in 1970 in Canada and used it a fair amount up there on my property which was an apple orchard. After moving away to the states (Texas) over 30 years ago I seldom used the saw. I would start it or use it briefly perhaps once a year and it never failed to start on the first few pulls and always ran great.

The other day I had the need for it to cut down a tree limb damaged by a recent storm and I could not get it to even fire...let alone start.
I dumped the old gas and put in fresh gas but still no luck. I pulled the spark plug and noticed it was flooded with gas so I cleaned it out and tried again...still no luck. It seems every time I tried to start it would flood the spark plug. I tested the plug to see if I was getting a spark and I was, so I am not sure why it is flooding and not firing up.

With some of the reading I've done on this forum the past few days it sounds like I may have carb problems or fuel line problems. My questions are:
1. How do I find out exactly what model of 041AV I have as there are several it seems? I cannot find a plate anywhere on the saw that shows the model number. There is a serial number 8318596 stamped on top but no model number. I notice in the parts manual I have it shows 041AVQ, 041AVEQ, 041SEQ, and 041AVFBQ but I cannot determine which is mine.

2. What could cause the saw to flood when I try to start it normally? ie with trigger locked on, choke on and switch to ON. Could it be just one of the fuel lines? I notice there is something called an impulse hose although I've never run across that before and not sure what it does.

3. Is it difficult to remove the carb to clean it and replace gaskets etc.??..I am pretty handy and have done this with my generator, weedeater and leaf blower and even my daughters old Poulan lawn tractor, but they seem simple compared to the Stihl. I've had to replace all the fuel lines on these other tools several times I guess because the lousy ethanol eats them up and rots them within a year.

I have never had to to anything to the Stihl chainsaw over the years except a new spark plug, even leaving in the fuel for a year or more it would always start and run strong. I guess the ethanol may have taken its toll on my saw too now.

It would be really handy to have a step by step manual with drawings to remove the carb on the Stihl as it seems to have many more parts than my other tools from what I see in the parts diagrams. My concern is taking it apart and finding myself with a box of parts then having to take it to a dealer to put back together....lol...embarrassing and expensive ! I'm very careful and methodical but without any prior knowledge of the 041 and no repair manual I am a bit concerned. I've not seen a repair manual...does it even give step by step instructions?

Sorry for the lengthy rambling and all the questions but I am just trying to be properly prepared to do this job and get my saw running again. Perhaps there is a thread on here that shows step by step with pictures how to remove, overhaul and rebuild the carb?

Thanks in advance for any advice or assistance from the members here.

 

[sefh3]

You need to take the top handle off of this saw to get to the carb. It's not bad but not as easy of the vertical piston saws. The carb and flange are known it vibrate loose. Replace the gaskets while you are there.

 

[Nate66n1]

To find out what model you have you could take that serial number to your dealer and see if it could be brought up in the computer or books. As said before it's not hard to replace the carb/intake gaskets. While your there you might as well rebuild the carb and replace the fuel and impulse lines just for good measure. If your showing spark when the plug is out then you might be able to put a new plug in it and give it a tiny tiny bit of starting fluid before installing the spark plug to try and dry the cylinder up. Huge emphasis on the tiny bit of starting fluid though. Sounds like the cylinder/crankcase might be loaded up with raw fuel. Another thing is to check your hi speed and low speed mixture screws. Hope this helps

 

[Wood Doctor]

You have a spark. You appear to have fuel making it to to the combustion chamber, but the engine will not start and run. My conclusion is that the engine is worn out and likely lacks compression to support combustion. Try replacing the rings first. It's the cheapest alternative.

 

[sirreal12]

041AV starting problem

I got the carb off and it is a Tillotson HS 138 so I am getting a rebuild kit for it. Also going to replace the fuel hoses and the fuel filter.
I may pick up another spark plug although the one in there now is fairly new and I am getting a spark when I test it. While I'm waiting for this stuff off Ebay, I'm giving it a good cleaning.....call me old-fashioned but I believe clean things work better...lol. I will post what happens when I'm done and try to start it again. Meanwhile if there are any other suggestions or comments...please feel free to reply.
Thanks

 

[Frank Boyer]

Pull the heat shield under the carb and replace all of the gaskets. Use locktite when you go back together. I used to change the gaskets and fuel/impulse lines every couple of years in light service.

 

[sirreal12]

041av won't start

Well I installed the Tillotson carb kit, replaced the fuel hose, put in a new fuel filter...cost a whole $18. Filled it with fresh gas and 1st pull away she went....runs great. As it turned out the plug was fine..just cleaned it up. A word on the carb kit...when I got it I noticed that the metering diaphram was different than the original. The new one had a different post in the center that would not hook into the lever arm that operates the needle valve. I was going to return the kit but decided to call Tillotson. The explained that this was a deliberate change to that part and that it would work fine just setting it on top of the lever arm. Obviously it works fine as the saw started right up and runs smooth. I didn't bother to soak the carb...just sprayed it with carb cleaner then blew it out with the air compressor and reassembled it with the new kit parts.

Thanks for the replies and help...I hope others have good luck solving their various problems as well.

PS: Now I have to check to be sure the oiler is lubricating the chain properly...not sure exactly how that thing works. I am wondering if one can run the saw without the bar and chain and cover to see if oil is actually coming out to where the two holes in the bar get the oil?

 

[Wood Doctor]

Well I installed the Tillotson carb kit, replaced the fuel hose, put in a new fuel filter...cost a whole $18. Filled it with fresh gas and 1st pull away she went....runs great. As it turned out the plug was fine..just cleaned it up. A word on the carb kit...when I got it I noticed that the metering diaphram was different than the original. The new one had a different post in the center that would not hook into the lever arm that operates the needle valve. I was going to return the kit but decided to call Tillotson. The explained that this was a deliberate change to that part and that it would work fine just setting it on top of the lever arm. Obviously it works fine as the saw started right up and runs smooth. I didn't bother to soak the carb...just sprayed it with carb cleaner then blew it out with the air compressor and reassembled it with the new kit parts.

Thanks for the replies and help...I hope others have good luck solving their various problems as well.

PS: Now I have to check to be sure the oiler is lubricating the chain properly...not sure exactly how that thing works. I am wondering if one can run the saw without the bar and chain and cover to see if oil is actually coming out to where the two holes in the bar get the oil?

Good News! To check the oiler, remove the bar and chain and start the saw with the bar/chain cover off. You should see bar oil flow through the port and into the channel that carries oil to the oiling hole on the bar.

 

[sirreal12]

041av oiler

Wood Doctor thanks for the reply. I checked and there is oil coming out. I added a little kerosene to the oil tank (maybe 1/2-3/4 oz.) in the hope that it cleans up the oiling mechanisms. Others on here recommended to do that on occasion and I never have.

I noticed that the Inner and Outer side plates are wearing....the rest of the saw is in perfect condition from what I can tell.
These side plates are 1113 664 1001 (inner) and 1113 664 1100 (outer) on the parts diagram and I notice they are riveted on.

Can they be replaced? If so do you or does anyone know where I can get a set?

thanks much !!

 

[Wood Doctor]

The side plates are riveted on? Sounds like a previous owner's modification. The plates have to be removed occasionally for cleaning and servicing.

You can probably contact a local Stihl dealer and order replacements. Not sure who else would have them. Nowadays the outer plate has been eliminated on most newer saws. The inner plate is still around and covers the chain tensioner mechanism.

 

[sirreal12]

041av side plates

Wood Doctor, yes they are riveted on and that is how the saw came brand new when I bought it back in 1970. Old 40 suggested that they are push in rivets and can be carefully pried out and re-used with the new plates. I do wonder though how well they will hold in the new plates given the vibration etc when the saw is being used. I just bought a set of plates off Ebay...a little pricey for what they are but be that as it may. I will try to put them on using the old rivets I pull out...but if they don't appear to be holding well I may either use a new aluminum rivet or even possible a small self-tapping screw in their place. I guess we'll see how it goes.

thanks