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

[smokey7]

Hello all i am the guy witb the light tan muffler. The saw was gotten with i believe to be sae 30 oil mix for 2 cycle oil. It smoked really bad for a good while. I have ran somewhere between 6-8 qts of oil thru it. Starting with penzoil aircooled for about 2 qts then citgo air cooled for a qt or 2 then its been on lucas fd for almost 4 qts. All at 32:1. This saw was super black and dirty with way more carbon everywhere. When i got it i scrubbed the muffler of all loose stuff with a wire brush, cleaned the port and started running it. It is tuned to a lite 4 stroke free rev and cleans up as soon as you touch wood. It is tuned real sharp. I am worried that with the tight tune i need a better oil or go alot richer. The plug is a light tan just like the muffler, just a little darker at the bottom of plug.

 

[bwalker]

Hello all i am the guy witb the light tan muffler. The saw was gotten with i believe to be sae 30 oil mix for 2 cycle oil. It smoked really bad for a good while. I have ran somewhere between 6-8 qts of oil thru it. Starting with penzoil aircooled for about 2 qts then citgo air cooled for a qt or 2 then its been on lucas fd for almost 4 qts. All at 32:1. This saw was super black and dirty with way more carbon everywhere. When i got it i scrubbed the muffler of all loose stuff with a wire brush, cleaned the port and started running it. It is tuned to a lite 4 stroke free rev and cleans up as soon as you touch wood. It is tuned real sharp. I am worried that with the tight tune i need a better oil or go alot richer. The plug is a light tan just like the muffler, just a little darker at the bottom of plug.

If its tuned as you say that plug wouldn't scare me. It's impossible to tell much from looking at a plug that's been ran for a long time. If you want to read a plug you must do a plug chop and then.inspect the area where the insulator meets the metal shell.

 

[bwalker]

This one was ran for quit a few years and was actually on the rich side.

 

[Ron660]

Real easy. 4oz per gallonView attachment 425656

I might try 4.5 ozs (28:1) in the summer to keep the mosquitos away.

 

[smokey7]

See that plug you showed looks more like the color i am used to. I am aware that a plug chop is needed with a new plug. I wish i had a tach to know how high it is revving. It is tuned to best performance, with a lite 4 stroke, i am just nervous from the less or different residual film and the light tan muff.

 

[Moparmyway]

Hello all i am the guy witb the light tan muffler. The saw was gotten with i believe to be sae 30 oil mix for 2 cycle oil. It smoked really bad for a good while. I have ran somewhere between 6-8 qts of oil thru it. Starting with penzoil aircooled for about 2 qts then citgo air cooled for a qt or 2 then its been on lucas fd for almost 4 qts. All at 32:1. This saw was super black and dirty with way more carbon everywhere. When i got it i scrubbed the muffler of all loose stuff with a wire brush, cleaned the port and started running it. It is tuned to a lite 4 stroke free rev and cleans up as soon as you touch wood. It is tuned real sharp. I am worried that with the tight tune i need a better oil or go alot richer. The plug is a light tan just like the muffler, just a little darker at the bottom of plug.

Too light for me for sure.
I dont mind leaving a little power on the table by having a little extra fuel and a little extra oil.
I have seen way too many motors look like that out the exhaust, and their internals are dry and heated.
Just my opinion, but I aint cookie cutting or timing my cuts. I would rather run a little fat and let the chain make the cut go quicker

 

[smokey7]

Yea i agree i am rethinking my tune. I have gone almost a 1/8 turn fatter and going to run it again today. I hope she gets a bit more color and oil film after i finish my last gallon of mix. I have 5oz of lucas left i am thinking of trying 24:1 also.

 

[Moparmyway]

Yea i agree i am rethinking my tune. I have gone almost a 1/8 turn fatter and going to run it again today. I hope she gets a bit more color and oil film after i finish my last gallon of mix. I have 5oz of lucas left i am thinking of trying 24:1 also.

Tuning a little more fat (like you did) will also bring a little more oil film along with it.
You might not need to go to 24:1, but you need to be comfy with how your equipment runs.

 

[smokey7]

I agree with that it runs phenomenal now it just doesn't seem to leave a lot of oil behind. It definatly got a blubber now after the tune change. I hope i see what i like soon.

 

[Trx250r180]

How long did it take to do that chain ?

 

[Moparmyway]

How long did it take to do that chain ?

Eh, just a stroke or two here and there .............. done in a few minutes

 

[Trx250r180]

Eh, just a stroke or two here and there .............. done in a few minutes

I did the rh side of a .404 converting to square full comp ,then hung it on the nail ,am used to skip or semi skips ,106 dl full comp takes forever . ,converted one to 10 degrees for milling on the usg ,that went pretty quick ,square ,not so much .

 

[nitehawk55]

Running an oil mixture too rich can be harmful too , the carb jet can't handle it and can actually make the saw run lean . I think 40:1/45:1 with a good oil is plenty .

 

[Whitespider]

...I aint cookie cutting or timing my cuts. I would rather run a little fat...

That's always been my thinkin' with small 2-stroke OPE, tune 'em just a touch "fat"... that's likely why I'm not afraid of a 50:1 mix.
Just my opinion, but I'm bettin' way more failures can be attributed to a lean tune than not enough oil in the mix... b'sides, extra oil can't compensate for a lean tune, it don't work that way.
Using OPE ain't a competition where the the first finisher wins a million dollar purse... ain't no good reason to run 'em on the edge.
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[Trx250r180]

To the guys running 50 to 1 in your stock saws ,am sure it is fine ,my saws are time bombs if i do that from the extra heat from higher compression ,being modded ,here is a 460 piston 50 to 1 stihl ultra off one of my "personal" saws i broked once ,after going 32 to 1 have had no failures . This saw was still starting up ,and had 225 psi with this piston in it .

 

[smokey7]

Yea i suppose i was on the edge. I backed it off now. That 460 looks wet on the bottom end for 50:1

 

[nitehawk55]

Oil wasn't the problem it's covered with it !

Modding changes all that .

 

[bwalker]

Running an oil mixture too rich can be harmful too , the carb jet can't handle it and can actually make the saw run lean . I think 40:1/45:1 with a good oil is plenty .

Carbs can handle it just fine...

 

[bwalker]

Oil wasn't the problem it's covered with it !

Modding changes all that .

It ran too lean..

 

[Whitespider]

To the guys running 50 to 1 in your stock saws ,am sure it is fine ,my saws are time bombs if i do that from the extra heat from higher compression ,being modded ,here is a 460 piston 50 to 1 stihl ultra off one of my "personal" saws i broked once ,after going 32 to 1 have had no failures.

Maybe I'm just missing something that can be explained to me... maybe not...
But adding more oil ain't gonna' reduce internal engine temperature enough to matter... and it can even increase it (depending). The oil is there for lubrication, the engine parts need only enough lubrication... anything more than enough is wasted. That piston, rod and crank in your picture look plenty "wet"... there appears to be plenty enough oil.

Running a 2-stroke lean will cause it to get hot... a whole friggin' bunch more hot. If I pulled that engine apart and saw that piston my first thought would be "lean", not oil starvation. I'd be thinking lean from either an improper tune or ethanol blended fuel (if I could see the top of the piston I might favor one cause over the other). Typically, in my experience anyway, adding more oil means opening the high side carb screw a little to make them run right... meaning the extra oil forces you to run the engine richer (more fuel), which is what's gonna' cool internal temperatures, not the oil... meaning ya' likely could have just run the thing a touch "fatter" in the first place and not added the extra oil.

Like I said, maybe I'm missing something... but...
When the gas/oil/air mixture enters the crankcase the gas vaporizes, the oil don't. Now you have tiny droplets of oil in there... like a fog, which collects and builds up on the internal parts. Moving parts, such as the crank, sling off any extra, throwing even more of it on places like the cylinder walls and such. What little oil that does find it's way into the combustion chamber doesn't do much for lubrication, it's either burned or just blown out the exhaust (4 stroke engines don't have any oil introduced into the combustion chamber and they survive). It's the vaporizing gasoline that carries away most of the heat (like your evaporating sweat)... running the engine lean means a lot less heat is carried away.

Extra oil can't compensate for a lean tune... it don't work that way.
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