D
Deleted member 83629
Guest
not sure but my runs the same with either mix only thing i noticed is the slight increase in smoke when it starts.
661 Oil Test 32:1 vs 40:1 vs 50:1 ?
- Thread starter redbull660
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KG441c
Keith
does it bobble off long idles ?
That's all the Mtronic system looks for.
D
Deleted member 83629
Guest
no its does bobble off long idles it has excellent throttle response. it never has bogged on me but the saw is a little cold blooded.
one.man.band
ArboristSite Guru
what does the solenoid in the elec carb do? wondering.
a. when it's "on" restricts fuel flow
b. when "on" allows more fuel to flow
c. none of above
d. thicken molecules
a. when it's "on" restricts fuel flow
b. when "on" allows more fuel to flow
c. none of above
d. thicken molecules
KG441c
Keith
A, B, and no doubt D
tree monkey
Addicted to ArboristSite
it opens and closes for every revolution of the engine. the longer it's open, the more fuel it gets
one.man.band
ArboristSite Guru
10-4.
was thinking it was a fuel- injector- like solenoid deal.
must use trigger pulse off the fly-wheel magnet.
one.man.band
ArboristSite Guru
.......simpler yet. no trigger. just skims a little bit off the coil each go round. may be better guess.
Trx250r180
Saw polisher
Need to figure this camera thing out ,tried on the mellow saw that rides in the pickup ,i think this is mobil one 
,but saw was run on h1r most of its life ,looks a little rich on the plug .Am curious what the 660 looks like that has been milling with mobil now,need to play around with this thing see if can get better image ,maybe the decomp hole ,these are through the spark plug hole
,but saw was run on h1r most of its life ,looks a little rich on the plug .Am curious what the 660 looks like that has been milling with mobil now,need to play around with this thing see if can get better image ,maybe the decomp hole ,these are through the spark plug hole
Trx250r180
Saw polisher
More pictures here is 440 hybrid ,has some weird wash marks ,the whole squish band is washed clean on the piston top ,is this common ? I can make out the D shape of the jug on the piston top .Oil mobil 1 , 32 to 1 I let the saw idle for a bit before shutdown is why wet plug . the letter S is on the intake side ,arrow facing the intake port .
Trx250r180
Saw polisher
Here is the milling 660 ,i was surprised by thick layer of carbon buildup ,maybe because it uses the fuel faster than normal time ? I go through a tank of fuel in about 10 minutes of cutting normally milling ,the carbon had crack lines all over it too ,the intake side was washed clean by the intake port ,the exhaust port where polished had very little carbon on it ,as the squish band was pretty clean ,most of the piston was pretty thick carbon on this saw .piston top is wet because let idle for a while too cool off after the long milling passes .looked more clear before took a picture of a picture ,i need to see if this tool will do a screenshot i can load to a pc somehow ,it came with a usb cord so it may do that .
thomas1
sodium pentothal
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Looks like it's a girl. Congrats, Brian!
Well it is a Stihl...
Trx250r180
Saw polisher
Haters
Ron660
Addicted to ArboristSite
What's your 660 tuned to (rpms) milling? Mobil didn't burn that clean in the 660?
Trx250r180
Saw polisher
I really dont know ,it was pretty thick carbon milling with h1r but had some grey deposits like ash,the mobil does not seem to leave the ash ,i have only used 6 pints of the mobil so far between 2 saws and the yard trimmers,if i was too rich on the milling saw i would think it would be washed clean ? Not built up so much,on the intake side the piston is washed in the one secton shaped like a triangle, the exhaust port was pretty clean ,it also has a stock muffler can with full baffle and a dual port cover ,that may ne why the carnon is cracking from heat build up ?
In some of the pics the crown looks good, others not so much. In the oil test preformed on a small RC aviation engine, the results looked much the same with Mobil 1. However in normal use M1 seems to burn extremely clean. My thoughts are.
1. Like you said the engine is breathing enough because of the restrictive muffler.
2. Two the engine isn't getting hot enough to keep the piston crown clean, because the tuning is a tad rich.
3. The fuel mix is simply not preforming well in this extreme application.
I would try a different mix with the same tuning. I don't see anything that really indicates the engine was running hot, M1 may just solidify in that application.
Big_Wood
westcoast dweller
how many hours you think you got on that 660 milling brian? IIRC that saw has a raisman platt crank in it? i've had good luck with the hutzl cranks as well. used 4-5 of them now and all saws are still running being neglected like normal.
Trx250r180
Saw polisher
I need to figure out how to take a screenshot with that tool and transfer to a pc ,the picture of a picture makes the black carbon look white ,on the head the whole dome chamber was black carbon of what i could see ,just the machines squishband was clean ,in the hybrids with 3 ports on the mufflers the piston has very little buildup ,the first hybrid has about 180 psi ,modded by a guy in canada ,the squishband has more carbon than on the saw with 230 psi done in tenn., extra transfers were carved on the intake side of that saw also ,and can see the tips of them in the images the whole outside edge of the piston on that saw was real clean where the whole squishband is ,middle of the piston is all carboned like normal
On the milling 660 it has a lot of hours with h1r ,and the exhaust had black spooge dripping from the seams of the muffler with that oil ,i am wondering if that is previous buildup and the new oil is staring to soften it up making the cracks ? it could be the choked up muffler also ,but it keeps the noise down considerably ,i may have to put the modded muffler on for a bit to see if too choked up .i also have a case of sabre to use up that is formulated for saws not dirtbikes .so i will see how this changes things on the crown .The camera is nice because you only have to pull the spark plug and the decomp hole or muffler cover to view the piston .
I really do not know at this point Shane ,I have lost track ,but the aftermarket Raismin crank has at least 3 times the hours the oem stihl one had on it before it snapped off at the clutch .I am thinking about an hour meter tach combo to put on the mill saw so can watch it better .
