coppicer

Christ. The pressure! ?

This is probably the next stop. If the main jet isn't doing its job - and yes, I did blast the external surface of the carb with air, but not the valves directly - is replacement the only way to fix it?

No improvement. Might be running a tad longer.

This one feels like plastic, not rubber (or metal). Will have a poke around.

Work a bit quieter, so back to the saw. Whipped off the carb (always wanted to say that!) and found fuel in the bottom. Using a magnifying glass, I set out to look a the metering arm as recommended by @spudulike. The inlet needle seems to be moving properly, and the spring doesn't look bunched. However, the metering lever does look a bit low, and when I depress it the needle doesn't seem to rise much. So maybe I need to pry that up as suggested in the Zama docs that @bmp01 kindly linked to earlier. Hard to get a good photo, but for what it's worth: So that's one thing to try. The second possible issue is the fuel filter. The old one looked OK, but I didn't realise how fragile it was and I damaged it while removing, so I replaced it. Perhaps I didn't position it very well - it looks a bit skewed in these photos. Forgot to say earlier - when removing the carb a rubber ring came off, which seems to have fitted between the filter base (carb bracket) and the carb itself. I think it is the No.12 "Stihl sleeve" in this diagram. Could that have been loose? Seems unlikely with the bolts pinched up correctly. Plan of attack: adjust metering arm so it lifts needle higher; make fuel filter level and flush with bore in which it sits.

I dislike poorly made things, and I hate having to buy twice. For most of my life I have by default bought quality tools, things like Snap-on, Knipex, Wera, Ko-ken, Silky, and a few other Japanese brands. I have gradually come to realise that quality is not equally valuable for all tools. Sometimes "good enough" really is good enough. I didn't think I'd be using a saw often enough to justify professional kit, and I assumed the MS181 would do what I needed it to do. And for seven years, up until a couple of weeks ago, I've been right.?

Fair point, but I can't say I agree. The basic problem - I think - is that I'm a ham-fisted mechanic without much experience under my belt. The saw itself is seven years old, been used by an unskilled owner and not maintained well. It hasn't been worked hard by arb standards, but it's put in some hours, albeit sporadically (sometimes I don't use it for months). For a non-professional saw, it's not done too badly. The owner, on the other hand... I agree that a more powerful saw would be nice, something not too heavy, perhaps an Echo 501. On the other hand, at the end of the day, this is mostly a hobby for me. I cut wood and drag bits of tree about because I enjoy it. I don't want to drop wll north of £500 on a new saw the current economic climate. Work-wise, I'm keeping my head above water, but the floods have only just started and may get considerably worse before they get better. I might need that £600 before things get back to normal.

Thank you @bmp01 that's very helpful - didn't think of looking at Zama's site. Have printed out that page and am studying it.

Sorry about this @bmp01 and @spudulike, but with regard to your comments, I'm using the Stihl repair manual and it doesn't mention a metering arm anywhere (only a metering diaphragm). Is it the "air valve lever" referred to in the screenshot below?

I'm all for doing the easy things first (and exclusively, if possible). Anyway, now been waylaid by wife to begin assembly of IKEA item. Looks possibly more complex than the carb. EDIT Furniture is supposed to have 20 screws, M4 x 10mm. There are only 19 in the bag...

Didn't check any of these! Thanks, will get onto it.

Er, I've been unscrewing it further! Is that the wrong direction?

Thanks, not had any luck with that so far, but I will try resetting all the screws. I replaced the pump diaphragm a few days ago and I don't think it's possible to put it back together incorrectly if you're following the manual, but maybe I did something wrong. On the positive side, bar oil is flowing through the saw, which is good - I was concerned that the oilways were blocked.

Hooray! Sort of. I gave it some fuel and oil. The saw fires as normal on choke, I flip it to normal, then it catches, runs for a second or two, then dies. Sometimes I can get it to rev for a few seconds. I'm assuming that this is a carburation issue? I dialled the three carb screws all the way in and out to what I thought was default, but maybe I got it wrong. Second issue: ring-a-ding-ding from the washer on the end of the crank stub in the picture below. It's held on by an e-clip, and there seems to be a lot of play, so it tinkles on over-run. I can't seem to find a close-up picture in the documentation as to which side should face out, so I'm thinking that maybe I have it the wrong way. Can anybody advise on either of these? Thanks.

Blimey. Once more recognisable as a chainsaw. Any tips for starting it up? Bit of oil, bit of fuel, not bother with bar and chain, just see if it runs...?

Forgot to take a photo of this fella when taking it apart. Got a flange. That's odd.? EDIT: Got it - front upper screw for rewind starter cover.

Well, have put back carb, now just fitting the baffle on the filter base, then I will do the nuts that hold the carb, and the screws that hold the filter base in place (I have sourced a couple to replace those that were mysteriously missing). As you can see, I haven't put the clutch back yet. I have a new sprocket, but it looks straightforward. The thing that worries me a bit is the nut, which tightens anti-clockwise. How should I tackle this? Should I try to wedge something in the starter thingummyjig on the other side? (Have put back the rewind starter but not screwed it down, so could whip it off if needed.) Or can I just give it a blast with the impact driver with the power dialled down a bit?

Sadly not, just middle age!

Work has been busy, but have a couple of free days. Carb is back on, more or less. Now contemplating the throttle rod in mild surprise. Can't even remember taking this off. EDIT: Ask and ye shall be given!

Thanks for that. It's not cheap, but I suppose cheaper than screwing up the carb!

On a slightly more serious note, I wasn't aware of the existence of welch plugs until yesterday. Do they actually need a special tool? Couldn't see any obvious way to extract or replace the one in the carb...

You mean earlier, when spud was advising me in no uncertain terms not to touch that poor, defenseless welch plug? Perhaps this one...

Gave saw, sitting in pieces on work table, several hard stares today as i passed. Nothing happened. Looks like I will have to reassemble it myself after all. ?

We looked young when we watched it the first time too I reckon...

Well, let's not carried away - no guarantee it will work after assembly! ?