My Solo 681 soiled the sheets

[guysmiley]

I know it's redwood, but seems like a lot of bar...

I agree with you, however... it is never pulling on the full length of bar in cut. Eventually if I can get my hands on a bigger saw I will bring it back down to a 32". The redwood I have to slab out is like butter for a full chisel skip tooth. I never lean on it.
It is what it is for now, work has to get done(about 6 more rips through these logs... what better way to help seat the ring ) and this is the biggest tool I got.

 

[guysmiley]

I wanted to give a year+ update... I thankfully got a stihl 075AV that wears a 48" bar and does the heavy lifting. My Solo has been running good, one quirk it has (and I think had before it blew) was a tendency to overheat cutting large rounds without a break. I will do maybe 3 32" doug fir rounds at a steady pace with her and if I push too much more she gets hot, If I let her idle a bit she will go as long as I want. Seems perfectly tuned, touch on the fat side. Much safer now wearing a 28" bar. I think I have put at least 15-20 tanks of 32:1 through since the rebuild. Probably change to 40:1 in the future... been running great so not much incentive to at this point. I have not yet returned to rip the big redwood that killed her, but when I do it will be for the 075. I have ripped a few of logs with that and what a joy!

The 681 is certainly my favorite saw by far out of my lineup for doing anything serious. Thanks again for the great resource here!

 

[rupedoggy]

Been running good at 32:1 so I am going to change to 40:1

 

[guysmiley]

Been running good at 32:1 so I am going to change to 40:1

care to explain? I was running 32:1 for break-in and extra lube for pulling the 42" bar. Now it is broken in and running a 28". Oem calls for 50:1 With the big bore kit(extra potential for bottom end stress) I figure 40:1 is a little on the safe side. Feel free to elaborate if you think I am making a mistake in my logic.

 

[huskihl]

I wanted to give a year+ update... I thankfully got a stihl 075AV that wears a 48" bar and does the heavy lifting. My Solo has been running good, one quirk it has (and I think had before it blew) was a tendency to overheat cutting large rounds without a break. I will do maybe 3 32" doug fir rounds at a steady pace with her and if I push too much more she gets hot, If I let her idle a bit she will go as long as I want. Seems perfectly tuned, touch on the fat side. Much safer now wearing a 28" bar. I think I have put at least 15-20 tanks of 32:1 through since the rebuild. Probably change to 40:1 in the future... been running great so not much incentive to at this point. I have not yet returned to rip the big redwood that killed her, but when I do it will be for the 075. I have ripped a few of logs with that and what a joy!

The 681 is certainly my favorite saw by far out of my lineup for doing anything serious. Thanks again for the great resource here!

It should run all day if it’s tuned properly. If It’s getting hot after a few cuts, maybe the fuel system isn’t providing enough fuel or you don’t have it tuned rich enough

 

[davidwyby]

40:1 might run cooler...also maybe higher octane. 87 runs hot for me in the desert.



...have you met @Bob95065 yet?

 

[guysmiley]

40:1 might run cooler...also maybe higher octane. 87 runs hot for me in the desert.



...have you met @Bob95065 yet?

Yeah, I considered the heat issue and even me ruined it but edited it out as I don't want to detail the thread as I know that the science is still out on that for some. I always get 91 and this condition exists in winter so a bigger carb might do the trick, like I said, it is set slightly fat. Maybe a muffler mod would help it breath some heat more but for now my life is keeping me busy with other priorities.

Have not met bob95065 yet, cool to know there are other CAD minded folk nearby.

 

[Bob Hedgecutter]

It should run all day if it’s tuned properly. If It’s getting hot after a few cuts, maybe the fuel system isn’t providing enough fuel or you don’t have it tuned rich enough

Or maybe its just that half dull chain showing up again?

 

[huskihl]

Or maybe its just that half dull chain showing up again?

Same difference. The saw doesn’t know if it’s the fuel, the chain, outside temp or an air leak that is causing it to heat up and go lean. Add more fuel and it goes away

 

[guysmiley]

Same difference. The saw doesn’t know if it’s the fuel, the chain, outside temp or an air leak that is causing it to heat up and go lean. Add more fuel and it goes away

Very sharp chain always, rakers dressed often, full chisel, skip tooth. Thing throws fat chips, and fast with an 8t sprocket, it does not bog down. Maybe I should try going richer but when I run it and it is buried in the log under load, I have it set where it starts 4 stroking when I take it off of load still in the log ant high rpm. Could be an air leak but then wouldn't it lose the 4 stroke just off load? Maybe Ill take some vid to see if you guys can catch anything I have been missing next time I am cutting up some rounds.

To be clear, you are saying it should be able to cut up an entire trees worth of rounds (say a 44" at base fir tree) as fast as you want without getting too hot as long as I stay with a 28" bar? T be real clear, it is not like I can only do 3 cuts and the saw has problems. The symptoms start after cutting through downed big logs without giving it a rest, the safe spot seems to be after working for a bit, cut 3 or 4 cuts one after the other(maybe 5 minutes of cutting?) and then give it a minute plus idle. Then there is no overheat condition I can detect. I really do feel as I am overloading the saw work/time.

While I have you here, there is one other noise, one from the muffler as it cools down I notice a metal PING once. While running there is a rattle which to me sounds like a baffle inside that has lost a spot weld or maybe one that is tearing. Is that common? I havent looked into cracking it open yet but that is kind of on the to do list someday for that saw.

 

[sean donato]

Any saw should have no issues running all day without over heating, given everything is working properly.

 

[huskihl]

Very sharp chain always, rakers dressed often, full chisel, skip tooth. Thing throws fat chips, and fast with an 8t sprocket, it does not bog down. Maybe I should try going richer but when I run it and it is buried in the log under load, I have it set where it starts 4 stroking when I take it off of load still in the log ant high rpm. Could be an air leak but then wouldn't it lose the 4 stroke just off load? Maybe Ill take some vid to see if you guys can catch anything I have been missing next time I am cutting up some rounds.

To be clear, you are saying it should be able to cut up an entire trees worth of rounds (say a 44" at base fir tree) as fast as you want without getting too hot as long as I stay with a 28" bar? T be real clear, it is not like I can only do 3 cuts and the saw has problems. The symptoms start after cutting through downed big logs without giving it a rest, the safe spot seems to be after working for a bit, cut 3 or 4 cuts one after the other(maybe 5 minutes of cutting?) and then give it a minute plus idle. Then there is no overheat condition I can detect. I really do feel as I am overloading the saw work/time.

While I have you here, there is one other noise, one from the muffler as it cools down I notice a metal PING once. While running there is a rattle which to me sounds like a baffle inside that has lost a spot weld or maybe one that is tearing. Is that common? I havent looked into cracking it open yet but that is kind of on the to do list someday for that saw.

You could be hitting the limited coil, as opposed to thinking it’s 4 stroking when you lift or reduce load

 

[guysmiley]

You could be hitting the limited coil, as opposed to thinking it’s 4 stroking when you lift or reduce load

I don't think it's that. With the 8t sprocket I never keep it full speed. That is an interesting thing to check though next time I will listen for it just in case. At this point I think a video would be in order. I will plan on taking on next time I'm doing rounds.

Any saw should have no issues running all day without over heating, given everything is working properly.

Running under load? I am running the longest recommended bar, running an oversized p/c without any other mod. I have a hard time believing that broad statement.

 

[huskihl]

I don't think it's that. With the 8t sprocket I never keep it full speed. That is an interesting thing to check though next time I will listen for it just in case. At this point I think a video would be in order. I will plan on taking on next time I'm doing rounds.

Running under load? I am running the longest recommended bar, running an oversized p/c without any other mod. I have a hard time believing that broad statement.

You should only ever run a saw full speed. That’s the only time the H jet setting works correctly. 3/4 throttle could potentially be delivering 20% more or less fuel than required.

And yes, your saw is designed to be run all day wide open throttle without issue. No chainsaw needs to take a break to cool down if they are tuned properly and the starter and fins aren’t full of sawdust

 

[Sidecarflip]

...and I thought a 'Solo' was a plastic cup for years now.....lol

 

[guysmiley]

You should only ever run a saw full speed. That’s the only time the H jet setting works correctly. 3/4 throttle could potentially be delivering 20% more or less fuel than required.

I will do three things thanks for the advice, one is richen it up a bit more, 2 will be check fuel vent, third will be investigate exhaust. Also buy a laser thermometer. Will report back.

 

[huskihl]

Don’t get me wrong. I have no idea if your saw is getting hot from running lean or if it’s tuned too rich. Usually if they’re getting hot they will score up the piston.
And I’d nix the IR thermometer. They will read 50–100° hotter or cooler just by changing the point of aim 1/4”. On top of that, neither you nor I nor anyone else here knows what is overly warm or too hot in any given exact spot.

For the most part, heat isn’t a bad thing (until it is). Allows you to add more fuel to cool it down and burn it effectively.

 

[sean donato]

I don't think it's that. With the 8t sprocket I never keep it full speed. That is an interesting thing to check though next time I will listen for it just in case. At this point I think a video would be in order. I will plan on taking on next time I'm doing rounds.

Running under load? I am running the longest recommended bar, running an oversized p/c without any other mod. I have a hard time believing that broad statement.

It's an accurate statement. You're not doing anything to your saw, that It wasn't designed to do. Something is wrong with it. I'm not sure what is wrong with it, but I can assure you something is not right if you have to let it cool down between cuts.

 

[guysmiley]

It's an accurate statement. You're not doing anything to your saw, that It wasn't designed to do. Something is wrong with it. I'm not sure what is wrong with it, but I can assure you something is not right if you have to let it cool down between cuts.

what I meant was that while cutting under load it is much lower rpm than wot out of cut. So yeah, in cut I am usually 90-100% throttle sorry for the confusion. The aftermarket p/c is %9 larger than design so I figure the exhaust should be opened up to flow at least that much more to keep up with it. I am not an expert at all with 2 strokes (or 4 strokes) so I am all ears. I will test for air leak, richen it up and see if it helps etc soon. Just have a lot going on at the moment. My memory of cuts and timing could be exaggerated as well as it has been a couple months since I ran it, was just updating this to clarify it was no longer a basket case as I had an inquiry hoping to buy it in that state.

All that said it would be great to get to the bottom of this, will report back

 

[davidwyby]

28" of skip in fir should be cake all day.