Weird piston action in a blown Stihl 500i

[OM617YOTA]

August Hunicke used to run a 36" bar with skip chain on his 500i, don't think he had any issues. I think he runs a 28" now, though.

Mine came with a 32" and I didn't care for the balance. I run a 28" and it balances perfect.

 

[sean donato]

I get the 36" is the biggest bar stihl reccomends, but it's an 80cc pro saw. I would expect it to hang in there and do its job.

 

[WI_Hedgehog]

Kinda take the wind out of my sails for getting one. No point in getting rid of my 390xp then. No issue with a 36" bar or running it all day.

touted as being able to handle a 36" bar by stihl. Heck even an old 80cc mcculloch would pull one all day. Kinda disappointing. Meh, just stick to what I currently got.

When I was at the dealer looking at a 500i he said they're a nice saw but the power is up high, they don't have torque down low like a 462 or 661, so the high-revving is annoying to some. (It has since sold.)

For every one I've seen in use, that's the case: the operator spins it wayyyy up and then puts it in wood. In the engineering world there's a saying: Speed kills. It's true, the faster something is run the sooner it dies, and it's not "linear," it dies much sooner (it's called exponential growth toward end-of-life). In the car world engine builders know an engine block is good for a certain amount of power, how fast you go through it is up to you--meaning if you're laying into the turbo constantly don't expect the engine to last 100K miles. It's similar with porting saws, the bearings and other mechanicals aren't being upgraded--there's no "frame brace" being put in. But, they're faster and you're making money, so all good.

I'm going to guess STIHL did the engineering and figured all that out. However, the forces involved create non-linear stress and the saw is light for its power, so personally I'd guess it's going to hit EOL sooner than 3,000-3,500 hours we expect out of other STIHL saws. I'd also guess a 36" bar is going to drag the RPM below its power band, putting a lot of load on the engine (unless the operator is careful to keep the RPM up).

 

[lone wolf]

Kinda take the wind out of my sails for getting one. No point in getting rid of my 390xp then. No issue with a 36" bar or running it all day.

touted as being able to handle a 36" bar by stihl. Heck even an old 80cc mcculloch would pull one all day. Kinda disappointing. Meh, just stick to what I currently got.

Maybe in Pine.

 

[HumBurner]

When I was at the dealer looking at a 500i he said they're a nice saw but the power is up high, they don't have torque down low like a 462 or 661, so the high-revving is annoying to some. (It has since sold.)

For every one I've seen in use, that's the case: the operator spins it wayyyy up and then puts it in wood. In the engineering world there's a saying: Speed kills. It's true, the faster something is run the sooner it dies, and it's not "linear," it dies much sooner (it's called exponential growth toward end-of-life). In the car world engine builders know an engine block is good for a certain amount of power, how fast you go through it is up to you--meaning if you're laying into the turbo constantly don't expect the engine to last 100K miles. It's similar with porting saws, the bearings and other mechanicals aren't being upgraded--there's no "frame brace" being put in. But, they're faster and you're making money, so all good.

I'm going to guess STIHL did the engineering and figured all that out. However, the forces involved create non-linear stress and the saw is light for its power, so personally I'd guess it's going to hit EOL sooner than 3,000-3,500 hours we expect out of other STIHL saws. I'd also guess a 36" bar is going to drag the RPM below its power band, putting a lot of load on the engine (unless the operator is careful to keep the RPM up).

What modern saw is lasting 3k-3500 hours?

 

[lone wolf]

Kinda take the wind out of my sails for getting one. No point in getting rid of my 390xp then. No issue with a 36" bar or running it all day.

touted as being able to handle a 36" bar by stihl. Heck even an old 80cc mcculloch would pull one all day. Kinda disappointing. Meh, just stick to what I currently got.

Why, do you cut more 36 in logs than say 24 in?

 

[WI_Hedgehog]

What modern saw is lasting 3k-3500 hours?

8 hours/day x 5 days/week x 30 weeks/year x 3 years = 3,600 hours

Three years of regular use seems very reasonable; most daily-use saws here see 3-5 years of use, companies that care for their equipment are seeing 4,000 to 4,500 hours of powerhead life. Companies that are rough on their stuff are seeing 2,500+, generally topping out at 3,000 hours.

I cannot speak for Husqvarna because that's not where my experience is*. Local tree services and landscapers seem to be getting that out of STIHL Pro saws, somewhat less for concrete cutting guys depending on if they take care of the equipment or wham-bam-thank-you-mam slam it in the truck.

The MS 261, 462, and 661 series are popular around here and have a great track record. I think the MS 400 will also, it seems to be another solid saw.

---
*Locally Husqvarna is a popular high-end homeowner saw sold primarily at big-box stores. Owners consider them very reliable, fast, light, and low-vibration, and I agree. By comparison STIHL is heavier, slower, vibrates more, and costs more, however crews consider them easy to start, more precise (probably due to less vibration damping), and far more reliable/longer-lasting and having lower Total Cost of Ownership by a wide margin. BUT, some local STIHL dealers tend to soak homeowners and cater to crews, whereas Husqvarna parts can be bought online, so there's that. Remember too, this is Wisconsin, so things are different than on either of the coasts. I own STIHL and loved the Pro Huskies I've run, but haven't run Husky enough to comment on longevity.

 

[ZeroJunk]

It would be interesting for somebody who is a logger or tree service to give a good estimate of what percentage of the day he is actually using the saw.
I would be surprised if it is even 30%.

 

[huskihl]

I get the 36" is the biggest bar stihl reccomends, but it's an 80cc pro saw. I would expect it to hang in there and do its job.

They run it fine in hardwood. I know guys that run them in the PNW cutting softwood with a 42”

 

[huskihl]

When I was at the dealer looking at a 500i he said they're a nice saw but the power is up high, they don't have torque down low like a 462 or 661, so the high-revving is annoying to some. (It has since sold.)

For every one I've seen in use, that's the case: the operator spins it wayyyy up and then puts it in wood. In the engineering world there's a saying: Speed kills. It's true, the faster something is run the sooner it dies, and it's not "linear," it dies much sooner (it's called exponential growth toward end-of-life). In the car world engine builders know an engine block is good for a certain amount of power, how fast you go through it is up to you--meaning if you're laying into the turbo constantly don't expect the engine to last 100K miles. It's similar with porting saws, the bearings and other mechanicals aren't being upgraded--there's no "frame brace" being put in. But, they're faster and you're making money, so all good.

I'm going to guess STIHL did the engineering and figured all that out. However, the forces involved create non-linear stress and the saw is light for its power, so personally I'd guess it's going to hit EOL sooner than 3,000-3,500 hours we expect out of other STIHL saws. I'd also guess a 36" bar is going to drag the RPM below its power band, putting a lot of load on the engine (unless the operator is careful to keep the RPM up).

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

 

[lone wolf]

It would be interesting for somebody who is a logger or tree service to give a good estimate of what percentage of the day he is actually using the saw.
I would be surprised if it is even 30%.

Tanks of fuel would be a good way to measure, time the first tank, and take it from there.

 

[WI_Hedgehog]

Tanks of fuel would be a good way to measure, time the first tank, and take it from there.

I run tachs on mine, hours are logged.

 

[Squareground3691]

They run it fine in hardwood. I know guys that run them in the PNW cutting softwood with a 42”

+1

 

[lone wolf]

I run tachs on mine, hours are logged.

Cant argue with that, then. What oil ratio?

 

[WI_Hedgehog]

Cant argue with that, then. What oil ratio?

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).

---
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.

 

[lone wolf]

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).

---
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 face 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 use Amsoil for a long time and have had no problems related to oil.

 

[ZeroJunk]

I run tachs on mine, hours are logged.

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 ?

 

[sean donato]

Maybe in Pine.

Not a lot of that around here...

Why, do you cut more 36 in logs than say 24 in?

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.

 

[chipper1]

Since I run mostly STIHL powerheads and am sure the engineers at STIHL know what they're doing

Stihl ultra is one of the nastiest oils I've ever ran .
Even you know it has issues...

It will clog spark arrestor screens if powerheads aren't run flat-out full-power.

For me it runs clean, but I'm usually on the throttle heavy.

 

[chipper1]

The 500 has about a 5000 RPM span where it’s comfortable running a bar and chain

What about without a bar and chain, asking for a friend .