Weird piston action in a blown Stihl 500i

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STIHL HP Ultra, 50:1 in STIHL powerheads, 40:1 in saws w/OEM 40:1 ratio, all are stock (not ported). That oil cannot be mixed heavy. It will clog spark arrestor screens if powerheads aren't run flat-out full-power. I keep an assortment of chains filed for different wood types and match the chain to the wood so the saw self-feeds and doesn't require downforce. For me it runs clean, but I'm usually on the throttle heavy. When not in the wood I let the saw idle, so not a lot of start/stops (and I'm usually on the ground, in the tree would be different).

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For reference:

Since I run mostly STIHL powerheads and am sure the engineers at STIHL know what they're doing, I run that. It seems to work fine in non-STIHL powerheads, so I mix 40:1 and tag those cans differently.

From what I'm told and have seen, Echo Red Armor seems good, it's 20% more expensive locally and can crap up the muffler over time, but the engine runs clean and other than looking dirty inside I haven't heard of any muffler problems...

AMSoil seems good in ported saws and it can be mixed heavy, which saw porters suggest--in fact for ported saws it seems "the oil" to run.

If I had Echo saws I'd probably run Echo Red Armor, the Japanese engineers also know their stuff and make great products. If I ran a ported saw I'd run a heavy AMSoil mix.
I wouldn’t run any saw at 50:1, personally. I don’t care what they say. IMO the whole 50:1 one thing is epa ********. bovine offal
 
I’m not sure where that info came from, but that is exactly the opposite of how a 500i runs. The early 462 had trouble with anything over 24 because it only had a narrow rpm range where it would run. The 500 has about a 5000 RPM span where it’s comfortable running a bar and chain
From someone that doesn’t own a 500i, I have 3, no issues whatsoever with 32” bar in hard Canadian Maple!
 
Curious. Exactly how is that done ?

Some software program ? Somebody offer the program with their tach ?

Hours at what RPM ?

Some ratio between idle RPM and working RPM ?
Induction tachometer, displays RPM when the saw is running, hours when not running. I idle my saws a lot, so that's recorded as "run time," not "total revolutions" nor something more complex like a computerized saw has. It gives me a general idea of usage, which is better than a Wild-Assed-Guess.

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Not a lot of that around here...

Well, (sorry kinda hijacking this thread.) Lately it sure seems like it, I've been running the 390xp w/ 36" b/c quite a bit. Comes and goes in spurts. The idea of a lighter saw capable of pulling a 36" was intriguing. Don't need it by any means though. Usually a 24" is enough.
Well I think the 24 on the 500I is a nice set-up if you like that idea try one first then buy it, it is the power to weight that makes the saw so desirable.
 
Induction tachometer, displays RPM when the saw is running, hours when not running. I idle my saws a lot, so that's recorded as "run time," not "total revolutions" nor something more complex like a computerized saw has. It gives me a general idea of usage, which is better than a Wild-Assed-Guess.

View attachment 1122086
Color matched and everything ,attention to detail!
 
Induction tachometer, displays RPM when the saw is running, hours when not running. I idle my saws a lot, so that's recorded as "run time," not "total revolutions" nor something more complex like a computerized saw has. It gives me a general idea of usage, which is better than a Wild-Assed-Guess.

View attachment 1122086
That is pretty cool. I suspect some smart person could write a program to determine whatever you wanted to know about usage. I just ain't one.
 
That is pretty cool. I suspect some smart person could write a program to determine whatever you wanted to know about usage. I just ain't one.
The problem is ruggedness: like an automotive ECU the circuit has to withstand vibration, scorching heat, freezing cold, have enough memory to store useful information, somehow communicate while preventing water ingres, and not use much power, all for a reasonable price that justifies the time and expenditure related to using it.

Hence the cheapie tach and industrial Velcro which has a thick shock absorbing layer on each side: it helps the tachs last and makes them easy to replace. :guitar:
 
Ummm... Is this a joke? 20 sold? Google says this conversion is just a sprocket kit basically. Scammer who sets listing to "Last one" to try and find a sucker with FOMO, I guess?
Yes and no but yes mostly

Everyone should open the item description and read it. The bedazaling BS is epic!
 
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