wood dust in the carb hard on the saw?

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Detonation could be caused by running lean, but not usually in a saw in my experience. Running lean does certainly heat a saw up quick though
Yeah for sure overly lean fueling will make it run too hot. Running too hot from lean fueling is what ultimately causes the detonation and cylinder damage…

When detonation occurs you sometimes actually see broken rings or more commonly little chunks of damage around the perimeter of the ring… different than the long term scoring that occurs from grit or metal shavings getting into the motor.
 
Based on the fact that the dealer wanted to charge you ~$1100 to repair I’d put him in the deceptive category. A piston kit is ~$250 and the labor time is less than one day.

Why would the tech buy the saw for $150 knowing that he’d have to dump another ~$250 into it (now $400 into the saw) for a saw that used goes for about $500. Maybe $750 if it’s extraordinarily clean.

It sure looks like the dealer wanted to move his 500. The tech spent half an hour and twelve dollars to repair the spark problem and sold the saw (scored cylinder and all) to someone for ~$450 for a quick $300 profit knowing it didn’t have much life left in it. Dealer gets to move inventory. OP gets a great deal on a new saw. Everybody’s happy.

IF the dealer wasn’t lying and it really had super low compression to the point where it couldn’t cut wood anymore it could only be from something getting in the piston hole when the plug was not. Something that wasn’t sawdust. All kinds of grit gathers around the plug hole. A little grease or oil around it could easily trap sand. Like someone mentioned the plug could possibly been cross threaded an itty bit and metal shavings would cause that damage. But only rocks sand or metal or the like could possibly cause sudden piston compression failure in that motor. Not sawdust.

So what’s the lesson? Pay attention when changing the plug? Don’t trust dealers? Get a second opinion on all repair estimates? Stay off the internet? 🤣

Idk but I’ve been entertained by this while we’re having lunch and waiting for the mill to show up today.

Have a good one everybody. Gotta get back to work !!!
 
I sadly must admit that fines were not the problem. The sawdust that was on the outside of the saw around the spark plug was unfiltered stuff, and I would guess some were more than 1/8" long. Though I brushed the area, I should have used compressed air to do a better job of cleaning. Expensive mistake on my part!

Write this down. Sawdust did not wreck your saw. Sawdust did not wreck your saw. Five hundred times.
 
Wood doesn’t destroy pistons—you’re right it simply burns. Dirt, grit, rock dust metals dust… yeah those will destroy pistons.

In the OPs case the symptoms of saw not running great occurred after spark plug change. So Occam’s razor it’s related to that—either the plug wire was fragile and broken already and manipulating it to replace the plug broke it more. (Spark from the coil is crazy hot and will jump across broken plug wires with ease) but if course the wider the gap the worse the saw runs…

No doubt the saw had scored pistons… but it wasn’t from the spark plug change. Scoring from leanout failure takes a long long time. This saw probably had scoring for a good long time and ran just fine.

I’d bet that either the plug wire was damaged and that damage was exacerbated during the plug swap. Or the gap got smashed but OP is confident that didn’t happen and I have no reason to doubt him.

But I’d also bet money the mechanic who bought the saw for $150 replaced the plug wire and put a new piston in it and that saw is running today. Or if he’s dishonest he replaced the plug wire and someone else is running it with the scored piston right now.

Unless OP was there to witness the compression numbers on the gauge I don’t believe the dealer saying it had low compression. Dealers have enormous pressure to move inventory. They gotta sell saws. Every month they sit on the shelf in inventory costs them money. They get incentives based on the volume of sales. Most shops make more money on SERVICE (repairs) than sales… but they’re in the sales business. They gotta sell inventory.

In California right now there are almost no gas powered saws available off the shelf. You have to order them. Because my dealer doesn’t want to carry the inventory. It costs him too much. That and California is pushing hard for everything from cars to chainsaws converting to electric…. But even the electric saws… the only thing they have on the shelf are the budget consumer grade type for joe homeowner.

Dealer has a 500i on the shelf that is a very expensive saw he sells for not much over his own cost? I say he was under inventory accounting pressure to get it off his shelf.
Maybe. But he only had 1 in stock. At that time, 500is were very hard to get at any price.
 
Based on the fact that the dealer wanted to charge you ~$1100 to repair I’d put him in the deceptive category. A piston kit is ~$250 and the labor time is less than one day.

Why would the tech buy the saw for $150 knowing that he’d have to dump another ~$250 into it (now $400 into the saw) for a saw that used goes for about $500. Maybe $750 if it’s extraordinarily clean.

It sure looks like the dealer wanted to move his 500. The tech spent half an hour and twelve dollars to repair the spark problem and sold the saw (scored cylinder and all) to someone for ~$450 for a quick $300 profit knowing it didn’t have much life left in it. Dealer gets to move inventory. OP gets a great deal on a new saw. Everybody’s happy.

IF the dealer wasn’t lying and it really had super low compression to the point where it couldn’t cut wood anymore it could only be from something getting in the piston hole when the plug was not. Something that wasn’t sawdust. All kinds of grit gathers around the plug hole. A little grease or oil around it could easily trap sand. Like someone mentioned the plug could possibly been cross threaded an itty bit and metal shavings would cause that damage. But only rocks sand or metal or the like could possibly cause sudden piston compression failure in that motor. Not sawdust.

So what’s the lesson? Pay attention when changing the plug? Don’t trust dealers? Get a second opinion on all repair estimates? Stay off the internet? 🤣

Idk but I’ve been entertained by this while we’re having lunch and waiting for the mill to show up today.

Have a good one everybody. Gotta get back to work !!!
He had another 441C that potentially would need parts.
 
It would seem that Bwalker is in a bit of a mood today..

Gonna grab a cold one and some popcorn, sit back and watch the magic..
He is always in that mood. But I suggest paying no attention to anyone who is so ignorant he thinks film strength and viscosity are the same thing.
 
I just thought it was time to change the plug after about 10 years. The old plug did not look too bad, but once I had it out, I figured I might as well install the new plug. I did not take pictures, and neither did the dealer.
So no evidence to support the claims then?
Roughly, how much debris do you think fell into the cylinder via the open spark plug void?
1/8th of a teaspoon full- more?
 
So no evidence to support the claims then?
Roughly, how much debris do you think fell into the cylinder via the open spark plug void?
1/8th of a teaspoon full- more?
I have no way of knowing, but 1/8 teaspoon seems like a lot to me. And any sawdust in that area had a bit of bar oil mixed in, making it sticky, which would tend to get dirt stuck to it over time. Possibly dirt carried in by the sawdust did the actual damage. In any case, it happened, and I will be more careful next time.
 
I have no way of knowing, but 1/8 teaspoon seems like a lot to me. And any sawdust in that area had a bit of bar oil mixed in, making it sticky, which would tend to get dirt stuck to it over time. Possibly dirt carried in by the sawdust did the actual damage. In any case, it happened, and I will be more careful next time.

So you have sawdust mixed with bar oil on top of the cylinder that contains some dirt and it remains tacky or to use your own description "sticky" despite being on what might be the hottest part of the cylinder exterior under normal running conditions- but not that sticky that it stays adhered to the cylinder and jumps into an open orifice?
 
Maybe. But he only had 1 in stock. At that time, 500is were very hard to get at any price.
Hey I think you got a super deal on an awesome saw. And thanks for sharing how you like it. Sounds like other than that quirk it’s a great machine. And I suspect you’re correct that the start/stop thing you’re experiencing is the fuel computer and A/F temp and etc sensors “learning” for the FI. Which one of the burdens and benefits of FI. But in this case 99% benefit 1% burden.

Motloecycles take a lot longer to warm up than chainsaws so their FI deliberately runs its super rich to avoid that stalling while its doing its learning on startup. Then after it reaches whatever temperature it backs off the rich mix and goes to optimum tuning.

I’m guessing that in a year or two you’ll find out that you can software update your saw to work out that sometimes-stalls-when-learning bug. So… fingers crossed for you dude.
 
Maybe. But he only had 1 in stock. At that time, 500is were very hard to get at any price.
Question: was this late in the calendar year by any chance? At the end of the year dealers get an enormous penalty for any inventory in stock. Not to mention they have to carry debt for every single thing they stock in the store… saws, chains, gloves whatever… so they’re under constant debt pressure waiting for sales to catch up and outrun they’re credit line. It’s just how business is done.

That’s why Q4 you see crazy sales by car dealers stores whatever everyone—it isn’t JUST because of the holidays. It’s because of the “inventory accounting penalty” sellers will literally give inventory away at cost just to get it off their books. It’s a math problem and sometimes they’ll even sell it for LESS than cost because it’ll hurt them worse if they hold onto it.

This fiscal year-end inventory thing is so severe that lots of companies change their fiscal year end to the end of Q2 or whatever other date they pick because they have better predictability on what’s going to be on their shelf. Something like 80% if all retail sales for luxury items occur in calendar year Q4.

I’m just saying the dude is running a business. Which is his right and I don’t begrudge anyone from working whatever way they choose to provide. But at a time when the saws were hard to get why why why wasn’t he selling it for $2k like some a-hole dealers in California were doing?

Idk why… but there was a reason. Maybe you’re a great repeat customer. Maybe he was looking at his payroll costs his lease cost his year end accounting inventory penalty coming and had to get all the hard to sell high dollar inventory GONE.

Because let’s face it… Stihl dealers probably make most of their sales off the inexpensive consumer saws for Joe homeowner because let’s face it… in the United States there are like a quarter million of THEM and how many thousands of US? (Shrug) just how it is.

And maybe I’m just a grumpy old man and jaded AF but for awhile I was sponsored by a motorcycle dealer and learned about how they made their money and what kind of pressures he was under. It’s an ugly competitive rough business. The things they did just to stay in business you wouldn’t believe.

I sure was glad about all the free stuff though 🤣

And you DID get a killer deal on that 500. In California you could sell it for what you paid for it right now this minute.
 
Stihl dealers don't have much mark up on any saw.
Reason why I find it funny when people say they won't rebuild a saw because they want to sell you a new one when they would make three times as much profit rebuilding one.

But, bars, chains, oil, parts, labor..... That is where the money is.

There are a lot of reasons not to rebuild a saw besides money. Like how long you estimate it will take the guy to tear it back up.
 
Stihl dealers don't have much mark up on any saw.
Reason why I find it funny when people say they won't rebuild a saw because they want to sell you a new one when they would make three times as much profit rebuilding one.

But, bars, chains, oil, parts, labor..... That is where the money is.

There are a lot of reasons not to rebuild a saw besides money. Like how long you estimate it will take the guy to tear it back up.
Agreed. That’s exactly what I said.

Dealers make far more in service than selling new saws.

The reason for dealer to be so motivated to move the saw isn’t profit—it’s accounting pressure for inventory, cost of carrying inventory and manufacturer pressure to promote the then-brand new model: the 500is…

And in this case the dealers tech bough the saw for $150 so guaranteed somebody made money off that…
 
I work for a Platinum Stihl dealer and all I do is work on Stihl. When I catch it up I go home. I'm too dumb to work the floor or the counter.
If you want to make money by far the best way is part them out on eBay.
Matter of fact Hermio should have sold it on eBay as being low compression.
He would have gotten a hell of a lot more than $150.
 
So you have sawdust mixed with bar oil on top of the cylinder that contains some dirt and it remains tacky or to use your own description "sticky" despite being on what might be the hottest part of the cylinder exterior under normal running conditions- but not that sticky that it stays adhered to the cylinder and jumps into an open orifice?
What I can tell you is that however hot the exterior is, it is not hot enough to either vaporize the gunk around the spark plus or burn it up. It was still tacky when I brushed most of it off with a paintbrush on the 441C, and I checked my MS500i, and it also has tacky junk around the spark plug. I don't expect to change that plug for years, but when I do, I will use compressed air first.
 
Question: was this late in the calendar year by any chance? At the end of the year dealers get an enormous penalty for any inventory in stock. Not to mention they have to carry debt for every single thing they stock in the store… saws, chains, gloves whatever… so they’re under constant debt pressure waiting for sales to catch up and outrun they’re credit line. It’s just how business is done.

That’s why Q4 you see crazy sales by car dealers stores whatever everyone—it isn’t JUST because of the holidays. It’s because of the “inventory accounting penalty” sellers will literally give inventory away at cost just to get it off their books. It’s a math problem and sometimes they’ll even sell it for LESS than cost because it’ll hurt them worse if they hold onto it.

This fiscal year-end inventory thing is so severe that lots of companies change their fiscal year end to the end of Q2 or whatever other date they pick because they have better predictability on what’s going to be on their shelf. Something like 80% if all retail sales for luxury items occur in calendar year Q4.

I’m just saying the dude is running a business. Which is his right and I don’t begrudge anyone from working whatever way they choose to provide. But at a time when the saws were hard to get why why why wasn’t he selling it for $2k like some a-hole dealers in California were doing?

Idk why… but there was a reason. Maybe you’re a great repeat customer. Maybe he was looking at his payroll costs his lease cost his year end accounting inventory penalty coming and had to get all the hard to sell high dollar inventory GONE.

Because let’s face it… Stihl dealers probably make most of their sales off the inexpensive consumer saws for Joe homeowner because let’s face it… in the United States there are like a quarter million of THEM and how many thousands of US? (Shrug) just how it is.

And maybe I’m just a grumpy old man and jaded AF but for awhile I was sponsored by a motorcycle dealer and learned about how they made their money and what kind of pressures he was under. It’s an ugly competitive rough business. The things they did just to stay in business you wouldn’t believe.

I sure was glad about all the free stuff though 🤣

And you DID get a killer deal on that 500. In California you could sell it for what you paid for it right now this minute.
I think I bought it in May or June; definitely not at year end. Though I will never know for sure, my suspicion was that the dealer looked up the wrong price; maybe wrong model or powerhead only? Who knows? In any case, I was not about to ask the dealer to re-check the price! I am not a great customer of the dealer, as their repair costs are very high; somewhere around $185/hour; maybe higher.
 
Stihl dealers don't have much mark up on any saw.
Reason why I find it funny when people say they won't rebuild a saw because they want to sell you a new one when they would make three times as much profit rebuilding one.

But, bars, chains, oil, parts, labor..... That is where the money is.

There are a lot of reasons not to rebuild a saw besides money. Like how long you estimate it will take the guy to tear it back up.
I imagine the dealer would have quite a bit of profit fixing my 441C for $1100!
 
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