661 Oil Test 32:1 vs 40:1 vs 50:1 ?

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It's really too early to tell much, but the things that concern me is the flaking you see on the crown. That's ash build up. There was also some on the head near the decompression valve. The other area of concern is the fact this stuff needs to be run pretty hard to burn cleanly. In wood more appropriate for this saw I have no doubt the buildup in the exhaust woukd have been worse.
 
It's really too early to tell much, but the things that concern me is the flaking you see on the crown. That's ash build up. There was also some on the head near the decompression valve. The other area of concern is the fact this stuff needs to be run pretty hard to burn cleanly. In wood more appropriate for this saw I have no doubt the buildup in the exhaust woukd have been worse.
The flaking is a result of the detergents trying to clean it?
 
It's really too early to tell much, but the things that concern me is the flaking you see on the crown. That's ash build up. There was also some on the head near the decompression valve. The other area of concern is the fact this stuff needs to be run pretty hard to burn cleanly. In wood more appropriate for this saw I have no doubt the buildup in the exhaust woukd have been worse.
Thats why i didn't like running Motul. My top handles were a black sticky mess, they get run hard but only for a short time, then idle, make a small cut, more idle and it just made a mess. Im sure its great for milling or making long bucking cuts though.
 
With the exhaust free flowing now the saw runs much cooler, i bet the plug and piston top would be dryer and less thick if was choked up running hot, more compresion would make more heat and burn a little cleaner with the exhaust opened up,i noticed this on my milling 660,after was ported it burned cleaner with modded exhaust.
 
The flaking is a result of the detergents trying to clean it?
Its actually not flaking. More like raised deposits.
These deposits are the result of detergents and antiwear additives burning off. They are mettalic compounds so they leave a mettalic based ash behind. 800 has a bunch of mettalics in it based on the VOA I saw for it, so this isn't a supprise.
 
Its actually not flaking. More like raised deposits.
These deposits are the result of detergents and antiwear additives burning off. They are mettalic compounds so they leave a mettalic based ash behind. 800 has a bunch of mettalics in it based on the VOA I saw for it, so this isn't a supprise.
Are you removing them before reassembling the saw.

And would would you expect them to still be there under "normal/appropriate sized wood."
Is the latter about 12-18" wood
 
That's probably the best advertisement for running 33:1 you can get. I couldn't imagine those flaking deposits would be good for anything other than getting caught in all the wrong places at at the wrong times!
Fainzst
 
That's probably the best advertisement for running 33:1 you can get. I couldn't imagine those flaking deposits would be good for anything other than getting caught in all the wrong places at at the wrong times!
Fainzst
You don't even know what your looking at old fool. And you don't know what ratio I was using either.
 
You don't even know what your looking at old fool. And you don't know what ratio I was using either.
Everybody is entitled to be a fool occasionally, I'm not going to make it an occupation like you have though!LOL

This rings a bell though, ha ha
"Thought I would track the progress of my MS 260 as I modify it.

This first video is stone stock, tuned to 14k running Motul 800T at 32:1 with premium ethanol free fuel"
 
H1r left that white crud in my piston , ash ? and plug also ,the mobil 1 is not so bad the dumonde tech dtp was real clean ,have not tried the sabre stuff yet ,i have a camera coming from snap on that has a probe with a light ,hopefully it can take images of piston top without pulling the jug off every time ,i do not have time to take the jugs off to look at stuff

I bet you will gain power with mobil 1 in that little saw ,the heavier dirt bike oils dogged power in my 50cc and lower stock equipment over the mobil
 
H1r left that white crud in my piston , ash ? and plug also ,the mobil 1 is not so bad the dumonde tech dtp was real clean ,have not tried the sabre stuff yet ,i have a camera coming from snap on that has a probe with a light ,hopefully it can take images of piston top without pulling the jug off every time ,i do not have time to take the jugs off to look at stuff

I bet you will gain power with mobil 1 in that little saw ,the heavier dirt bike oils dogged power in my 50cc and lower stock equipment over the mobil
That whitish crusty stuff is ash. I would think saber ran at normal ratios woukd be worse in this regard.
After a half gallon at 32:1, I switched to 40:1. I noticed no real differance in how the saw ran. The exhaust outlet stayed a bit cleaner.
Motul is really good oil. I just think there are better choices for my needs and conditions. YMMV.
 
Pulled down my new ms 260 to do a base gasket delete and this what it looked like. Motul 800 and premium ethanol free fuel.View attachment 451330 View attachment 451331View attachment 451332View attachment 451333
The tuning looks right on, the deposits are from the fuel and oil, not just the oil. Deposits (if your fuel mix doesn't change type) reach a steady state and I ignore these in my 2 cycles as long as my tuning is OK.
ps. What sealant are you using instead of a base gasket? Thanks for the photos.
 
The tuning looks right on, the deposits are from the fuel and oil, not just the oil. Deposits (if your fuel mix doesn't change type) reach a steady state and I ignore these in my 2 cycles as long as my tuning is OK.
ps. What sealant are you using instead of a base gasket? Thanks for the photos.
Loctite 518.
 

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