Cutting brush with a 500i?

[hacskaroly]

While I agree with you guys about the abuse and also 50:1 mix what I'm wondering is why would a 462c and a 500i run side by side not have the same results? The 462's have been having their own issues but its what I would consider normal breakage. but like I said I've had 6 blown 500i's and 0 other blown powerheads. So what makes a 462 more durable in brushing operations than the 500i? This is what has me puzzled.

I wonder if the difference in operation plays a part, when you stomp on a 462 (mTronic or carb adjusted) it ramps up and when you let off it ramps down, almost like a sine wave (analog) where as when you stomp on the 500i, its almost instant full throttle, more like a digital square wave (on-off-on-off-on-off). Its possible that as opposed to say cutting a tree or firewood, where the 500i is running at more constant speeds for extended times (to get through the cut), when going through brush, its cutting through the small stuff faster than it can calculate its extended needs and ends up running the saw more lean over time and with the heat buildup and you end up with a roasted saw.

Do you get any information from hooking it up to the computer? I wonder if it shows information that would be helpful beyond starts/attempted starts. I wonder if there is any correlation of hours worked, hours ran vs idling. Not sure if they show any temperature deviations.

 

[Nate.]

I really wanted to take them back to my local dealer and have them plug into them (for research of course ) Unfortunately I was told that wouldn’t be possible. I’m not exactly sure what the computer can tell you but I do remember my dealer saying it records the WOT RPM.

 

[Stihlalltheway]

I’ve blown up 3 500’s on fires, almost every time it was a lot of short throttle blips through small stuff then bar buried for extended periods of time and they got really, really hot and scored on the exhaust side. The going lean while brushing then doing hard work like bucking and falling in a hot environment causing scoring would make sense, but I’d think if it corrects fast enough to make it go lean through brush it would richen back up in the big stuff, either way I don’t use a 500 anymore and the 440’s and 460’s and 461’s are way better

 

[Nate.]

I keep seeing old red lever 044's and some 046's come through on the small town engine crews. They are often thrashed but still run like a top. I did have a High hour 461 come in this morning though. big end bearing shattered into a bunch of pieces and one of those little bits made its way to the upper edge of the piston and dug a groove in the plating all the way up before it seized at tdc.

 

[Wilhelm]

While I agree with you guys about the abuse and also 50:1 mix what I'm wondering is why would a 462c and a 500i run side by side not have the same results? The 462's have been having their own issues but its what I would consider normal breakage. but like I said I've had 6 blown 500i's and 0 other blown powerheads. So what makes a 462 more durable in brushing operations than the 500i? This is what has me puzzled.

It's the injection on the 500i!
Gotta be.

 

[Woodwackr]

It's the injection on the 500i!
Gotta be.

Or…the damn 50:1 crap.

 

[Nate.]

Or…the damn 50:1 crap.

Wouldn't that score a 462c though too?

 

[Woodwackr]

Wouldn't that score a 462c though too?

Has to be a combination of factors but I still think the ratio is a big part of the problem.

 

[sawmikaze]

Or…the damn 50:1 crap.

I think 50:1 gets blamed too much sometimes.

If there wasn't 1000s of chainsaws killing trees every day at 50:1 I'd agree, I've watched saws get tortured for years daily on 50:1 that are alive and well.

Not that more oil isn't better..but..I think it gets stretched.

 

[Czed]

I think 50:1 gets blamed too much sometimes.

If there wasn't 1000s of chainsaws killing trees every day at 50:1 I'd agree, I've watched saws get tortured for years daily on 50:1 that are alive and well.

Not that more oil isn't better..but..I think it gets stretched.

I talked to some amish guy's still running 30+ year old mostly 025 029/390s
Running 50/1 and if there's ever anyone that'll get the last bit of life out of a saw the amish will
I don't care for 50/1 myself but they'll live on it.

 

[sawmikaze]

I talked to some amish guy's still running 30+ year old mostly 025 029/390s
Running 50/1 and if there's ever anyone that'll get the last bit of life out of a saw the amish will
I don't care for 50/1 myself but they'll live on it.

I have a dozer dan 346 that goes on tour with my friends for months at a time..sometimes I forget it's even mine, that saw has been ran on gas station oil at 50:1 and has cut more firewood and killed more tress than 95% of this forum can even fathom..it's alive and well.

So..there's more to it..obviously..if 50:1 killed saws like some say that saw woulda been history years ago.

 

[Firewood Hoarder]

My takeaway from all of this is that I don't want a 500i. It seems to reinforce my gut feelings of not trusting the autotune systems.

 

[Hinerman]

Which is bs since the tax payers bought them in the first place

Here is the problem. Employee A gets all the salvageable parts, and uses the parts, or sells them on Ebay; not a bad side hustle. Employee B-Z get pissed and file complaints. Uncle Sam says nobody will get any parts from now on, we will trash them.

I had a similar issue with my city clearing trees for a parking lot. There were some huge pecans. I stopped and asked if I could cut some and take it for myself. Supervisor said "No, if we let you, we will have to let every Tom, Dick, and Harry also. If somebody gets hurt cutting the wood, the city could be held liable. If somebody doesn't get hurt, the somebody else will be mad because they didn't get a chance to get some." They hauled it to a dump and burned it.

 

[Woodwackr]

I have a dozer dan 346 that goes on tour with my friends for months at a time..sometimes I forget it's even mine, that saw has been ran on gas station oil at 50:1 and has cut more firewood and killed more tress than 95% of this forum can even fathom..it's alive and well.

So..there's more to it..obviously..if 50:1 killed saws like some say that saw woulda been history years ago.

Interesting. The 346 of his that I have…04, I think…is on 32:1 at his suggestion.
I have run it at 40 when that was the can I had with me

 

[sawmikaze]

Wouldn't that score a 462c though too?

My first 462 made it 5 years, almost to the month, it cracked it's nuts this past spring.



It paid me 1000x over, It got a new piston and it's back at it.

 

[sawmikaze]

My takeaway from all of this is that I don't want a 500i. It seems to reinforce my gut feelings of not trusting the autotune systems.

If you use it under normal conditions they are fine, ours is 3 years old and only had 1 incident where it didn't wanna run right, they aren't too bad.

 

[Moparmyway]

I believe that the larger saws need more oil, smaller saws can run longer with less oil.

The 346 is only 50cc’s
The 462 is 72 cc’s
The 500i is 80 cc’s

Try running 50:1 in a 7910 or an 064 and cut brush …….. prolly neither one of those would last much longer than the 500i’s are

 

[FederalQ]

Has to be a combination of factors but I still think the ratio is a big part of the problem.

The ratio and probably stale gasoline that‘s lost some of it‘s octane. For years a small shop here would emphasize Mix Only What You Need for the job.

 

[Nate.]

I also don't have a ton of faith in these guys ability to mix fuel correctly..... I got a 461 in today that was smoking bad, Like smoke screen bad. I asked about their fuel and they swore they mixed a good batch of 50:1 just this morning! I emptied the fuel and put some of my mix in and what do you know after about 30 seconds of running it quite smoking! If I had to guess I'd say it was running at least 25:1 probably worse.

 

[Woodwackr]

For years a small shop here would emphasize Mix Only What You Need for the job.

Amen