Why are all my 2-strokes stalling-out when, during heavy-use, I let-go after heavy throttling?

[Cerberus]

Is it possible that some 2-stroke powerheads simply run so darn hot that you're going to need to open-up your H&L jets a bit while "pushing" such powerheads? I ask because I'm getting stall-outs on almost every piece of gear I own (including my blower) in the most-specific way: Once hot, when using unit at full-power, if I quickly/immediately release throttle it will stall instead of falling to idle >:-( A gentle pull of the starter and it eagerly re-starts, but this is annoying so you open L a bit (maybe turn-up your Idle-screw too) and then it's fine. This is happening on most of my gear once it's hot and I'm "pushing it"....

Yesterday I was putting my new 355t to its 2nd "real job" and it quickly fell into this problem, I don't even need to go outside to know that - now while it's cold - that its L will be too-rich because I left it open yesterday (what sucks is knowing I didn't turn-up H, I wasn't thinking well enough I guess but I just "prevented the stall-outs" by opening L & increasing Idle screw's RPM's, I didn't touch H so am guessing I was running lean in-the-cut >:-( )

Makes sense in a way-- if the unit gets hot, the gas is hot & expands and is weaker-per-volume than before, so if your fuel has less bang-per-mL then you'd need to turn-up your jets to compensate....just hate the idea that 4-of-5 of my powerheads have this phenomena and "need hot *and* cold carb settings"!

*Any* advice/insight on tuning or what's up here would be greatly appreciated, am swapping-saws when they feel hot but jeesh my 355t got hot enough to exhibit this behavior in like 20min of use yesterday!

 

[Cerberus]

hmmm....the Similar Threads tool landed me in one where I found @Gunn 's post* (odd his name won't hyperlink..)

Saws 4 stroke at varying rpm. It's possible to have a saw four stroke out of the cut, but the rpm is miss matched to the size of the job and temp.

Example my 064 4 strokes all day 14.5k rpm. That's perfect for cutting smaller sized wood. But If I turn around and buck up a large oak with a long bar, that's probably not the best tune to use for that size wood and you may want to consider dialing things back to account for larger longer cuts and outside temps if it's summer time. Your mileage may vary.

This actually seems to answer my Q....and isn't the answer I'd hoped for, am thinking the 355t is simply not designed to sit there "making cookies" from a felled-Oak, but is instead meant just for in-tree, on&off use while aloft (which is fine, had just thought I could go-at the fallen trunk with it but as mentioned it kept running hot / requiring too-much an increase in L setting to stay-alive after heavy cuts, gah I'm guessing I did do some non-zero level of damage by not opening-up H to match it, was on-job and only thinking of keeping it running IE didn't occur to me that L needing a change means H would too)

Makes me want an IR thermometer, also gonna try finding some charting/graphing of how much energy is in a mL of fuel based on its temperature, had known altitude changes air-density which changes optimal carb-settings (ie you bring fuel down since your air has less oxygen-per-volume at high altitude) but hadn't considered it in terms of "your unit is hot therefore its fuel is of course hot", gonna get in-habit of finding HVAC compressors I can set my saws on when-appropriate lol



*post was here: https://opeforum.com/threads/can-a-saw-be-too-lean-even-if-it-four-strokes.1920/#post-84672