What oil is best? and what ratio?

[Kozak Logging]

I would buy a gallon of each Redbull660 and test it cutting firewood or in the woods. So that way your not wasting "time or money". Your actually using it for accomplishment as well as testing at the same time. temperature and altitude are always factors due to the longer and cooler burn of higher octane. Did anybody adjust there jetting settings with difference octanes to compensate for longer or shorter burn time and higher or lower burn temps?

 

[Kozak Logging]

When we ran turbo blue/110 octane we could jet leaner as it burned longer, not sure if that would work on saws or not. But its worth a try. Get it to 4 cycle and back it off a tish so it cleans up in the wood and re-time the cuts and see where you stand. vise versa

 

[bwalker]

When we ran turbo blue/110 octane we could jet leaner as it burned longer, not sure if that would work on saws or not. But its worth a try. Get it to 4 cycle and back it off a tish so it cleans up in the wood and re-time the cuts and see where you stand. vise versa

How did you determine it burned longer?

 

[Kozak Logging]

How did you determine it burned longer?

We did plug chops. We determined that it burns a tad longer when your jetted for 87 octane. We drained out the 87 after having it perfectly tuned. We ran 110 and did plug chops and noted and seen that the plug was rich looking. So we had (2) of the same atv's and we jetted one specifically for the 110 octane. we decreased our main jet two size and the pilot jet we left alone and just backed off the fuel mix screw. We ran side by side for a few days of trail driving. The 110 octane averaged 2 mpg better than the 87 octane tuned as it took less fuel as it ran more effiecently. Also we both had trail tech vapors and were able to monitor and set all of our settings to the same. Same distance traveled, same speeds. we switched who was leading and following. It didn't matter. Thats one of the tests.

 

[bwalker]

A plug cop is the correct procedure for testing jetting. It doesn't tell you burn speed.

 

[junkman]

I have been noticing that my atv engine results do not work the same for a shorter stroke smaller bore chainsaw .I had to run race gas in my 250r with the jug and head it had done by Arlen @LRD in oregon ,where my saws can have more compression and get by with 87 .

 

[bwalker]

I have been noticing that my atv engine results do not work the same for a shorter stroke smaller bore chainsaw .I had to run race gas in my 250r with the jug and head it had done by Arlen @LRD in oregon ,where my saws can have more compression and get by with 87 .

Larger bore takes longer to combust hence it's octane requirements are higher. Not to mention the BMEP factor.

 

[junkman]

Larger bore takes longer to combust hence it's octane requirements are higher. Not to mention the BMEP factor.

I added that so the atv dyno results could be thrown out the window when talking about saws .

 

[junkman]

I tried some saber yesterday ,tree felling and limbing them after stuff was very sooty using same carb settings i had for the mobil 1 mx2t ,plug turned black tuned to 15300 on the ms440 ,exhaust was soaked also compared to the mobil
mobil plug


Same plug with saber tuned to 15300,it actually idled nice ,and had good response being this rich ,muffler was soaked .exhaust washed with the saber also .Sort of like the h1r used to do in my saws .

 

[Moparmyway]

VP C14 (118 octane) has a lower specific gravity than VP C85 (98 octane)

the C14 will vaporize easier and burn faster than the lower octane C85

Its not just the octane number that must be considered, as Ben states in many of his posts, all parameters of a fuel must be carefully examined to make the best choice

 

[bwalker]

VP C14 (118 octane) has a lower specific gravity than VP C85 (98 octane)

the C14 will vaporize easier and burn faster than the lower octane C85

Its not just the octane number that must be considered, as Ben states in many of his posts, all parameters of a fuel must be carefully examined to make the best choice

It really goes beyond just looking at the SG. You need to look at both the end point and the 10% boiling point.
Many guys have a problem understanding this because they can't wrap their mind around the fact that in a properly running two cycle the fuel should nearly all flash to vapor within the crankcase.

 

[bwalker]

I tried some saber yesterday ,tree felling and limbing them after stuff was very sooty using same carb settings i had for the mobil 1 mx2t ,plug turned black tuned to 15300 on the ms440 ,exhaust was soaked also compared to the mobil
mobil plug
View attachment 4844

Same plug with saber tuned to 15300,it actually idled nice ,and had good response being this rich ,muffler was soaked .exhaust washed with the saber also .Sort of like the h1r used to do in my saws .View attachment 4845 View attachment 4846

I'm not supprised.

 

[Brian Simonseth]

Vary interesting read so far

 

[Kozak Logging]

What are you guys looking at as far as when you look at the plug? What part of the plug are you looking at? The eletrode? The porceline? The porceline color is what you should kind of go by to get a basic idea. Looking for a nice chocolate brown. to dark brown. black is rich and white is lean for those that may not know and are new to mechanics.

 

[bwalker]

The area to look at is where the porcelain meets the shell. And it's only accurate if you do a plug chop under load with a new plug.

 

[Kozak Logging]

Can't do accurate plug chops on saws. Theres no variations to check 1/4 throttle all the way to full throttle loaded in wood and unloaded. That's imho

 

[junkman]

Can't do accurate plug chops on saws. Theres no variations to check 1/4 throttle all the way to full throttle loaded in wood and unloaded. That's imho

That is why i just pull them out after a day of work to see how they look ,if getting a clean or sooty general burn .I am going to try to lean out the saber some more ,but i am at 15300 right now on a 440 hybrid ,try 500 more rpm see if cleans it up .The finger ports seem to make the insides wetter than my other saws .

 

[bwalker]

Can't do accurate plug chops on saws. Theres no variations to check 1/4 throttle all the way to full throttle loaded in wood and unloaded. That's imho

A plug chop only checks the main jet or full throttle operation. No reason it can't be done in a saw. But honestly with a saw cut and feel works just as good as anything.

 

[bwalker]

That is why i just pull them out after a day of work to see how they look ,if getting a clean or sooty general burn .I am going to try to lean out the saber some more ,but i am at 15300 right now on a 440 hybrid ,try 500 more rpm see if cleans it up .The finger ports seem to make the insides wetter than my other saws .

This really doesn't tell you much other than a very coarse view. Certain oils and fuel cause different color deposits, which skews this further.

 

[bwalker]

What are you guys looking at as far as when you look at the plug? What part of the plug are you looking at? The eletrode? The porceline? The porceline color is what you should kind of go by to get a basic idea. Looking for a nice chocolate brown. to dark brown. black is rich and white is lean for those that may not know and are new to mechanics.

What a plug chop looks for is the faint carbon ring that's present on a fresh plug when operated at full throttle full load. As the jetting gets leaner the rings gets smaller and more faint.
I once had a half dozen plugs that I turned on a lathe. Each plug was a main jet siz leaner than the next. Sadly I lost the photo in a computer crash.