Lugnutz
ArboristSite Operative
Too much nitrous?:jawdrop:
What would cause this?
- Thread starter blsnelling
- Start date
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Here is a pic of the mixture ring. This engines on the slightly rich side. FWIW I cut the threads of with a lathe.
Here is a pic of the mixture ring. This engines on the slightly rich side. FWIW I cut the threads of with a lathe.
Great example. Most don't realize the area that must be "read" is at the base of the porcelain.
Justsaws
Addicted to ArboristSite
The saw is being operated in a manner not consistent with its current carb setting.
The fuel quality is poor.
The air filter is passing to many fines, most likely from being loaded up quickly but appearing as though it is clean.
After hard use the saw is not being idled or cleared before being shut off, this effect is compounded by all the other aforementioned issues.
The fuel quality is poor.
The air filter is passing to many fines, most likely from being loaded up quickly but appearing as though it is clean.
After hard use the saw is not being idled or cleared before being shut off, this effect is compounded by all the other aforementioned issues.
^^^^^^
Sounds a little extreme if you ask me. I know the guy that runs the saw. Your comment about the saw not idling after milling is not only speculation, but completely and utterly inaccurate.
The saw getting hot had nothing to do with negligence, ignorance, or carelessness. Fuel quality? Maybe. Dan is very conscientious about what fuel / oil goes into his saw. Air filtration? I don't have much there, doesn't seem to make much sense if you ask me. If I had to give you any credit on one presumption it'd be the carb setting - but I just don't know. He and I get together and run our saws often, we take turns running our saws and are always playing around with taching them and whatnot. I'd be surprised if it's the carb though, that 441 runs like a friggin' top.
Sounds a little extreme if you ask me. I know the guy that runs the saw. Your comment about the saw not idling after milling is not only speculation, but completely and utterly inaccurate.
The saw getting hot had nothing to do with negligence, ignorance, or carelessness. Fuel quality? Maybe. Dan is very conscientious about what fuel / oil goes into his saw. Air filtration? I don't have much there, doesn't seem to make much sense if you ask me. If I had to give you any credit on one presumption it'd be the carb setting - but I just don't know. He and I get together and run our saws often, we take turns running our saws and are always playing around with taching them and whatnot. I'd be surprised if it's the carb though, that 441 runs like a friggin' top.
It was set as rich as possible against the stop, however lean that may be.
:kilt:
Justsaws
Addicted to ArboristSite
No insult intended.
A question was ask and an answer was given. The condition of the P/C in the photos is not rare or difficult to fix. The issues are minor and caught early. Retune, shop for better fuel, oil air filter or clean more often, operate saw after retune at the high end of its operational rpm during entire cut and cycle it for a longer period of time before shutting it down, blip the throttle a couple of times at least after a short idle period(10+seconds).
Fuel glazing on the outside and inside of the piston.
Particulate/contaminate baking and glazing on sides and top of piston.
Minor dusting on intake side of piston and cylinder.
Minor heat transfer damage on piston and cylinder.
My guess is poor quality fuel, combined with hard use on the saw. Milling is hard on any saw, and I don't think the 441 is really qualified as a milling saw. I remember Lake advised to richening an 066 for ex.quite a bit when used for milling. The 441 being a lean running saw as it is, it could be that the limiter caps do not allow enough richening for this purpose.
If he mills long enough with this saw, he will burn it up sooner or later.
If he mills long enough with this saw, he will burn it up sooner or later.
7sleeper
Addicted to ArboristSite
+1
It has been discussed here in german threads quite often that inadequate plastic bottles break down and give off that strange black carbonization.
It is typical if the people use any other containers not designed for gas storage. The only other container that is not supposed to deteriorate is the small oil jugs you get at department stores.
I also agree that the saw is definately running to "hot".
7
lawnmowertech37
Addicted to ArboristSite
ethonol could have a factor
Bingo
ill say rings not sealing and or improper oil previously http://www.theultralightplace.com/pistons.htm
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I have to jump in here..and what my speculation is has probably already been said. Actually I've seen exactly the same several times and the common denominators are:
1) Run hard before complete beaking..ie. race bike off the show room floor right to track and run the crap out of it.
2) Dirivative of no. 1 Running a synthetic during breakin...and the stuff doesn't let the break in (In particular the rings never really seat) happen in a "normal" amount of time...then back to one.
3) High heat caused by combination of things and When the saw (two stroke) is shut off, it does a partial sieze..then cools enough to where the user would never know. Things that combine to cause similar issues:
a) Lean mixtures,
b) too hot a plug.
c) Slightly advanceed ignition
d) Too low an Octane fuel
e) blow by from incomplete breakin.
f) High Loads, comprimised cooling. (Slow tracks or woods riding)
g) A combination of the above.
I've seen this with 1970-1980 era 125's. With first generation synthetics. Saw it again with four strokes on warrentee working for a motorcycle company. In all those situation the break in wasn't complete and they were exposed to racing therefore high loads. The blow by exaserbated the high heat appearance. They all had excessive blow by when not broken in properly.
The "Italian" motorcycle company I worked for had the recommendation on their bike to break in with a "Dino" oil and once the little "blue" puff's of smoke in the exaust stopped on decell then switch to Synthetic for the duration of the motorcycle life. Usually took those motors 25-30 hours to break in.
My guess is that saw never quite seated its rings (Thus the blowby), is lean from the factory (tendancy to run warmer), is used in a high load situation to allow the heat to build. Knowing who this is..milling is a longer duration cut than most saws experience.
My humble opinion is after rebuild/ring replacement, break it in longer with a more normal situation, run a richer fuel mixture than the limiters allow, after breakin run a synthetic at 32:1 minimum. This is a testament to the good stuff in that saw. Must be high quality material in that piston & cylinder. (I have run 32:1 for years and years and 25-30 years ago seeing exactly this situation was one of the reasons I went that direction)
Is that whats happening here? Smarter folks than I, will have to determine that.
1) Run hard before complete beaking..ie. race bike off the show room floor right to track and run the crap out of it.
2) Dirivative of no. 1 Running a synthetic during breakin...and the stuff doesn't let the break in (In particular the rings never really seat) happen in a "normal" amount of time...then back to one.
3) High heat caused by combination of things and When the saw (two stroke) is shut off, it does a partial sieze..then cools enough to where the user would never know. Things that combine to cause similar issues:
a) Lean mixtures,
b) too hot a plug.
c) Slightly advanceed ignition
d) Too low an Octane fuel
e) blow by from incomplete breakin.
f) High Loads, comprimised cooling. (Slow tracks or woods riding)
g) A combination of the above.
I've seen this with 1970-1980 era 125's. With first generation synthetics. Saw it again with four strokes on warrentee working for a motorcycle company. In all those situation the break in wasn't complete and they were exposed to racing therefore high loads. The blow by exaserbated the high heat appearance. They all had excessive blow by when not broken in properly.
The "Italian" motorcycle company I worked for had the recommendation on their bike to break in with a "Dino" oil and once the little "blue" puff's of smoke in the exaust stopped on decell then switch to Synthetic for the duration of the motorcycle life. Usually took those motors 25-30 hours to break in.
My guess is that saw never quite seated its rings (Thus the blowby), is lean from the factory (tendancy to run warmer), is used in a high load situation to allow the heat to build. Knowing who this is..milling is a longer duration cut than most saws experience.
My humble opinion is after rebuild/ring replacement, break it in longer with a more normal situation, run a richer fuel mixture than the limiters allow, after breakin run a synthetic at 32:1 minimum. This is a testament to the good stuff in that saw. Must be high quality material in that piston & cylinder. (I have run 32:1 for years and years and 25-30 years ago seeing exactly this situation was one of the reasons I went that direction)
Is that whats happening here? Smarter folks than I, will have to determine that.
Last edited:
willsaw4beer
Addicted to ArboristSite
If I had to speculate I would say the limiter caps caused the problem by not allowing the carb to be adjusted properly.
opcorn:
opcorn:
the westspartan
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Hey guys,
First off Merry Christmas!
Second, as many of you know, the saw in question is mine. I brought it to Brad to get it woods ported. It runs great. I mill with it frequently and as recently as Monday, the day I left New York to go to KY for the Holidays.
A little history about this saw.
-It was bought in October 2008.
-I ran two or three tanks through it with stihl dino oil and switched it to Woodland Pro Synthetic which is what I have run until the last few tanks when I used Stihl Ultra.
-I did some light milling with it right away.
-I use a standard 2.5 Gallon red plastic fuel can to store my mix in.
-I mill mostly white pine and always let the saw idle a minute or so after long cuts before shutting it down. If you have never milled Eastern White Pine, it is a treat. It is soft and fast to mill.
-I use only 92 octane or better fuel.
-I live in a rural area, but typically buy fuel from a gas station in the more populated village area or off the interstate so I believe there is pretty good turnover in terms of fuel stock.
-I have never touched the carb adjustments on this saw. I tached it this summer at 13,300 at WOT warm out of the cut and it holds it rpms well in the cut.
-MY THEORY AS TO THE OVERHEATING last summer I milled a decent amount of dead dry ash (20 to 22 inch). It was 90 degrees or better that day. I had trouble with it dying while idling between cuts, so I called my dealer. His theory was vapor lock, which seemed plausible. At that same time I was getting to the end of my 2.5 gallon can of mix and decided to get a new batch and dump the old. With the new fuel the idling problems were solved. I believe that batch of fuel may have been old when purchased or boiled off more quickly in the hot summer temps that month. It was probably 2 months old but no more than 3. I typically try to use mix within a month or two of purchasing. When I am in milling mode this is no problem, but when I am working firewood or felling, fuel lasts a LONG time with this saw, as other strato owners will attest to.
-Since the above mentioned incident, I have notice no loss of power with this saw and have had no further problems.
-As a number of my fellow NY AS members have mentioned, this is a strong running completely stock work saw that gets worked pretty hard but is taken care of.
That is all I can think of at the moment.
Thanks to everyone who is weighing in and watching this thread. A BIG thanks to Brad for starting this thread and being so thorough in his work. I dropped my saw off yesterday (Christmas Eve) and before I left we had looked at his collection of saws
ran a few of his saws and he had completely taken my 441 apart!
First off Merry Christmas!
Second, as many of you know, the saw in question is mine. I brought it to Brad to get it woods ported. It runs great. I mill with it frequently and as recently as Monday, the day I left New York to go to KY for the Holidays.
A little history about this saw.
-It was bought in October 2008.
-I ran two or three tanks through it with stihl dino oil and switched it to Woodland Pro Synthetic which is what I have run until the last few tanks when I used Stihl Ultra.
-I did some light milling with it right away.
-I use a standard 2.5 Gallon red plastic fuel can to store my mix in.
-I mill mostly white pine and always let the saw idle a minute or so after long cuts before shutting it down. If you have never milled Eastern White Pine, it is a treat. It is soft and fast to mill.
-I use only 92 octane or better fuel.
-I live in a rural area, but typically buy fuel from a gas station in the more populated village area or off the interstate so I believe there is pretty good turnover in terms of fuel stock.
-I have never touched the carb adjustments on this saw. I tached it this summer at 13,300 at WOT warm out of the cut and it holds it rpms well in the cut.
-MY THEORY AS TO THE OVERHEATING last summer I milled a decent amount of dead dry ash (20 to 22 inch). It was 90 degrees or better that day. I had trouble with it dying while idling between cuts, so I called my dealer. His theory was vapor lock, which seemed plausible. At that same time I was getting to the end of my 2.5 gallon can of mix and decided to get a new batch and dump the old. With the new fuel the idling problems were solved. I believe that batch of fuel may have been old when purchased or boiled off more quickly in the hot summer temps that month. It was probably 2 months old but no more than 3. I typically try to use mix within a month or two of purchasing. When I am in milling mode this is no problem, but when I am working firewood or felling, fuel lasts a LONG time with this saw, as other strato owners will attest to.
-Since the above mentioned incident, I have notice no loss of power with this saw and have had no further problems.
-As a number of my fellow NY AS members have mentioned, this is a strong running completely stock work saw that gets worked pretty hard but is taken care of.
That is all I can think of at the moment.
Thanks to everyone who is weighing in and watching this thread. A BIG thanks to Brad for starting this thread and being so thorough in his work. I dropped my saw off yesterday (Christmas Eve) and before I left we had looked at his collection of saws
ran a few of his saws and he had completely taken my 441 apart!
Good to hear from you Dan. It's obvious the saw has been well cared for. I'm convinced the only thing wrong with this saw is lean tuning due to the EPA mandated limiter tabs. I'd also recommend 32:1 from now on when milling, 40:1 otherwise. As I mentioned yesterday, I'd tune it as rich as I could when milling, just lean enough to quit 4-stroking under heavy load. I'm laying out your port work now.
FATGUY
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can't go wrong with synthetic 32:1 IMHO.
have you measured the ring end gap and are they in spec?
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