550xp Scoring
- Thread starter skylogger
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zogger
Tree Freak
What type of fuel can are you using?
I still have a hard time believing that type of discoloration and buildup happened in just 6 tanks of fuel, and for this to happen twice now is questionable, but I guess anything is possible. Take into consideration weed eaters and blowers run at lower rpm's and lower temps than saws, so what happens in a saw might not in a blower.
We don't really know what the dealer allegedly fixed after he first took it in. My wild guess is..not very much! That could be why it still looks rank. Don't know, can't say, even the OP can't say, he wasn't back on the bench at the dealers. New ring, throw it back together with the old cylinder?? Who knoweth....
Thing is, this is autotune, no limiter caps, no user adjustment, it is supposed to "just work". And by all acounnts here, MOST of them "just work". Most guys here have zero probs, and the dealers here have reported zero or minimal probs, but..we have had a few reported with problems, and I for sure saw one with serious problems.
*shrugs*
The dealer did not fix this saw, it is a brand new one that the OP received after his first blew up. Read the previous posts...
Mike from Maine
Read that the ms362 is awesome!!!
One would think that the OP would be very careful about his fuel mix after blowing up his first 550xp :shrugs:
Good grief guys if I was any more careful about mixing fuel I would need a degree in nuclear physics lol but seriously my brother has had a ms210 for at least six years and he could care less what fuel or oil he puts in that thing and it runs like a champ and always has.
Mike from Maine
Read that the ms362 is awesome!!!
That's what I figured.
It's not inconceivable that you got two duds that came off the assembly line one after the other.
SawTroll
Information Collector
2xdefective carbs is possible, if both are early ones - I would like to know the serial number of both saws
zogger
Tree Freak
Thought I did but was mistaken. either way, weirdness....but not terribly out of the ordinary either, many different saws/purchases have been taken back more than once.
I know it is a PITA for the OP, but stuff happens, and a good dealer will figure it out and make it right.
20123200*** was the first one, 20130900*** was the second
I see nothing in the first video that indicates a lean tune, I can even see a nice coating of oil. However that is not to say at some point the saw wasn't running lean.
At this point I'm at a loss, but I it still looks fuel related IMHO.
514mach1
ArboristSite Operative
I cooked the piston pretty good in my 272xp a couple years ago. I was using the 40:1 mix ratio (was using 50:1 a lot too, but switched to 40:1 on everything at about that same time) I always do. My friend mixed it exactly as he does for his honda 250 dirt bike... put the gas in the jug, measure out the oil, and pour it in the jug. And that was the problem. The gas had the bluish color of mix, but the top half of the jug was probably 150:1 and the bottom part was like 10:1. He usually put the oil in at the gas station after he'd fill the jug and I suspect the ride in the back of the truck is what normally 'mixed' it for him. When I mix gas, I leave just a little in the jug (don't empty it completely) and pour in the oil. Shake that up so there's like a 5:1 mix, then pump in the gasoline and as it's filling it all mixes up.
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zogger
Tree Freak
You take it back to the dealer yet?
nmurph
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I wonder why there is a horizontal line about 1/3rd the way up the piston, there is some scuffing below it and there is very little scuffing immediately above that line. Farther up, the scuffing is more severe.
Majorpayne
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Could the line be a shadow?
nmurph
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No, it is visible in the video.
spike60
Addicted to ArboristSite
Hmmmmmm
Not too sure there's anything wrong with the saw. The OP is understandably gun shy after having the first one blow up. But the color of what we are seeing in the pics and vid indicate to me that it's more like smudging than scoring. My main question is how much time is on this saw? I'm guessing it's hardly been run at all. And, he says that it's running fine at the moment.
I can take any saw off the shelf and duplicate what we are seeing here. Just did it with a 550, 372 and 2260. Pull the thing over slowly and it looks God awful. But the apparent "scoring" can be wiped off with a rag. The horrible looking score on the intake side on my saws corresponds with the location of the ring pin. After some running, but well short of breaking in, a smudge may not wipe off easily with a rag, but it's still simply a by-product of the assembly process. Murph's comment about the horizontal line also supports this line of thinking.
Just saying that this may not be as bad as it seems here. I invited Skylogger to give me a call and maybe we can figure it out a little more clearly.
Not too sure there's anything wrong with the saw. The OP is understandably gun shy after having the first one blow up. But the color of what we are seeing in the pics and vid indicate to me that it's more like smudging than scoring. My main question is how much time is on this saw? I'm guessing it's hardly been run at all. And, he says that it's running fine at the moment.
I can take any saw off the shelf and duplicate what we are seeing here. Just did it with a 550, 372 and 2260. Pull the thing over slowly and it looks God awful. But the apparent "scoring" can be wiped off with a rag. The horrible looking score on the intake side on my saws corresponds with the location of the ring pin. After some running, but well short of breaking in, a smudge may not wipe off easily with a rag, but it's still simply a by-product of the assembly process. Murph's comment about the horizontal line also supports this line of thinking.
Just saying that this may not be as bad as it seems here. I invited Skylogger to give me a call and maybe we can figure it out a little more clearly.
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nmurph
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It looks to me like the machining is missing from the piston in the area of the scuffing.
I agree with Bob about witness marks on pistons, but this looks a little more serious.
I agree with Bob about witness marks on pistons, but this looks a little more serious.
