Op, swapping out fuel lines and the whole carb is not tough or time consuming in the field on a tailgate. On my string trimmers I replace fuel lines every other year since the e-10 kills them on the Redmax trimmers I prefer. These days carbs are cheap enough to keep a spare on hand if your working in the bush. What's a day of down time cost including a trip to get parts? New fuel lines and a carb swap take ten minutes or so. Don't let minor issues stop you dead and cost a day or more.
And that black plug should be telling you something. Grab a lil screwdriver and turn a screw. Plenty of vids here to show you how to tune a carb. With your time in the woods, you oughta know what sounds right and what doesn't. No excuse to run them pig rich till they quit.
Yeah, I hear you about not having time to become an expert on everything mechanical. But basic tuning and fuel system service is a necessity if your going to earn your living with these tools. Otherwise down time and road trips to dealers will eat too much of your bottom line.
As a shop owner/operator, I run in to the opposite problem. People want to put as little money as possible in to their equipment - bare minimum fixes, Chinese parts, etc - and expect it to be problem free forever.
I always try to steer them in to proper overhauls - new OEM fuel/impulse lines, intake boots, air filters, etc. I prefer it when stuff goes out the door and doesn't come back for years.
Writing a planting bid proposal tonight, can only skim some of this. Thanks everyone for reading and responding.
I use clearing saws for Forestry work on sites of 2-70+ acres. I think anything smaller than the 40cc class I run now is better suited for small property management type work where you can pick up a chainsaw easily enough. I might cut 200 2" stems and then run into three 5" Oak I need to cut. Do I wade back through 100 yards of slash to get a chainsaw? I am looking forward to running the 50cc Stihl, though assembling more than one of them will be very slow. Husky hasn't released a new clearing saw model in many years now and quit selling their 50cc model altogether, and haven't put Auto-Tune in any of them yet. My friends in Canada report that hundreds of those M-Tronic 560s are in use up there and zero Husqvarnas.
The dynamics are the same as with chainsaws. You can cut a 20" tree with a 50cc saw if you have to, but how many of those will you do like that in one day? How long would that saw last? I can't use trimmers with a blade for woody stems. I will check the more exact details of the suggestions soon. I only sometimes get to cut Pine all day, I have probably more work in deciduous species (Soft Maple primarily) and every so often shade-grown suppressed trees can have essentially a kiln dried 2x2 in the centers.
I only hope my 55 can be a back-up saw when I need one. For example I have a friend who helps me on weekends in the fall for extra Xmas spending money, but he owns a 70cc and a 90cc saw, too big for the work I do. I ran the 55 for two years (NOT year-round), 2-3 weeks at a time, and basically retired it when I bought a 346XP. I let my dad use it some one winter and then it had issues it has never recovered from. I bought the 55 because my Dad owns a couple and before ethanol problems hit, saw problems were things like broken muffler bolts and hard mechanical issues that could be solved with a spare parts saw around. Swapping rubber parts isn't the same.
When I had one of the clearing saws finally diagnosed with a bad intake boot I started to wonder - what is the point of replacing the rubber parts of a carb, but not the fuel line or the boot? If bad fuel or bad storage on my part damaged one part of the fuel system, the others probably took some problems too. That saw had first the carb replaced (my original mechanic never told me I could just have the carb re-built, we were both learning about ethanol problems the hard way). Then a year later it had the fuel lines replaced. Then it continued to build idle = air leak. No one could find it. I didn't know about intake boots either. Finally my friend's local shop in a neighboring state found it. The saw ran almost like new for the first time in years. Unfortunately, these boots seem to be stuck somewhere on a ship in the middle of the Atlantic, as they are back-ordered for at least another month out right now, so I can't put them in the other two saws.
Someone mentioned the definition of insanity. To me it seems silly to replace cheap, small little parts of the fuel system one at a time. I feel fairly sure age alone causes them issues. Do I perfectly purge the line every time I stop using a saw? Does weather or client or employee or vehicle chaos change things when there might be fuel in a saw? Do I leave them for six months with a little fuel in them (No). Six-ten days sometimes, possibly.
When problems hit my 346 this spring, it was the last day of a job. After lunch it just got more and more raggedy. But I was moving on to other work - planting, very time sensitive. I would be busy with 7 day weeks for two months. Normally I would have checked the plug and filter myself and probably put in a new one out of my tool box, but I was out of spares of each right then. That would be just to get started on diagnosing it. Maybe I would have wire brushed the plug and listened again, turned to my more experienced friend and perhaps taken a new go at turning the jets on my own. Simple problems I can fix. Today I moved the T up on my one working brush saw another 1/8 turn after four stalls in an hour and got it back to the sweet spot. I can only pray it stays there for a while.
But since I had to go to the shop to get a good plug and filter for the toolbox anyway (and ask for help with the 55, again), I asked them to take a look, also in large part because my gut feeling was it wasn't just an over-used plug or dirty filter as I do change them perhaps too often. And they ended up replacing one of the rubber parts, though I didn't jot down exactly which in my saw notebook unfortunately and that particular shop doesn't give detailed receipts. It ran for about two tanks and then became nearly impossible to start. But I was off to another job and I put it in a shop there, for once just 15 minutes from the site's gate. They ordered the ubiquitous 'carb kit', installed it, and gave it back to me a month later. Now it doesn't run for even ten minutes.
Thanks someone for the tip on the vent. It has been worked on twice on that saw, for leaking like a sieve. One item I figured better for an experienced guy to sort out. I wouldn't guess a plugged vent could shut down the saw.
I have plenty to learn and this site helps some times. I don't run the saws year-round, but I have been running saws on and off . I just know several trips to the shop could have been saved with replacing the whole fuel system at once, rather than the wait-till-it-breaks approach. But when I request that all of the fuel handling parts be replaced, I am talked out of it every time. And eventually I am back at the shop to replace a fuel related part.
I'll read the whole thread soon, good night.