KG441c
Keith
Strange thing is Ive ran 110/87 50/50 @ 32to1 with 800t and my 461 piston looked just like bwalkers picture but I was tuned upwards of 14500
Premix 101: Oils, Ratios, and Fuel
- Thread starter blsnelling
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czar800
ArboristSite Guru
Well fuel makes up the biggest part of the mix. Last time I rode bike bikes the only one having plug problems was a guy running 100/1 or 80/1 mix of some high dollar oil. I've seen some ugly pistons from 4 strokes also, fuel burns dirty...
cedarshark
Addicted to ArboristSite
So, if one were to believe the authors dyno tests, we would all be running 32/1 as a compromise between maximum power and protection. As I believe some of the builders are proponents of a 32/1 ratio, this seems further evidence that this ratio is a very good one. I for one intend to try it.
I continue to tell my customers 32:1, no less than 40:1 with a full synthetic.
bitzer
******** Timber Expert
I cut for 5 hours a day. Subtract an hour for walking, swapping out chains, fueling up, wedging. So thats 4 hrs per day, 20 hrs per week, 1000 hrs per year. I run two tanks thru the saw in about an hour. Another way to figure it is by volume. I cut 1.3 million board feet last year. I average 1300bf per hour. Again, 1000 hrs. I could go on. We could figure it in gals of bar oil if you'd like. I can tell you approximately how many pulls you'll get out of recoil or how many rims I go thru or whatever. How many hours you'll get out of a bar or chain. Unless you have a different way of measuring time down there. I also know how many hours I put on my skidder and how many hours I put in on the job. If i could make money cutting 1.5 to 2.5 hours per day like your numbers come out that would be great. You gotta work a little harder than that tho. I need to run 7-8 tanks thru my 390 to make money for the day. My point in my first post was to illustrate from experience that oils and octane aren't all what they are cracked up to be. Its the mix and how you have it jetted as well as regular maintainence.
bitzer
******** Timber Expert
Yes sir! Guys who cut for a living know. Im sure he will come back with a long drawn out answer.
bitzer
******** Timber Expert
To be honest I'm running 37:1. Pump gas has so much crap in it its never going to burn completely or efficiently. Run fresh and run hard. Thats the difference. I noticed no lack or fouling when I switched to 87. Timberwolf always ran 87 too. I bought the hype for years on running 93. Gets to be a pain tho.
927 burnt clean for me. It was high load milling. I can get super techniplate to burn clean as well milling. Never ran the Benol
cedarshark
Addicted to ArboristSite
So if a guy switches from 50/1 to 32/1, when I retune, am I looking to go richer or leaner ?
You're getting less fuel, so you'll need to go richer.
one.man.band
ArboristSite Guru
agree with brad, was good read and info. do like the jennings/jerry branch test better.
first response of mine came with my first sip of coffee this am in regards to this:
"A typical example: you go from a 50:1 ratio to a 20:1 ratio. Your engine will now run leaner, and you’ll have to make jetting changes. You’ll need bigger (in number) jets because the oil molecules are thicker and the flow rate (the amount coming through the jet) is less."
usually, the only way oil gets thicker, is by a temperature change to colder. thinner when warmer. (viscosity change). same for honey, molasses, and just about anything else.
when i read that, thought he must be using magic oil molecules.
after re-reading it about five times, have to think what he was trying to say, was that as more oil is added to the fuel, the viscosity of the fuel/oil mix is increasing (thickening) thus causing less of fuel rate through the jet?
oil molecules are thicker. - meh
first response of mine came with my first sip of coffee this am in regards to this:
"A typical example: you go from a 50:1 ratio to a 20:1 ratio. Your engine will now run leaner, and you’ll have to make jetting changes. You’ll need bigger (in number) jets because the oil molecules are thicker and the flow rate (the amount coming through the jet) is less."
usually, the only way oil gets thicker, is by a temperature change to colder. thinner when warmer. (viscosity change). same for honey, molasses, and just about anything else.
when i read that, thought he must be using magic oil molecules.
after re-reading it about five times, have to think what he was trying to say, was that as more oil is added to the fuel, the viscosity of the fuel/oil mix is increasing (thickening) thus causing less of fuel rate through the jet?
oil molecules are thicker. - meh
one.man.band
ArboristSite Guru
.........and the only reason i brought it up this morning, was so that walker would get a laugh. its only oil. mellow out man. meloooooooooooooooow.
Its never not worked well for me.
Also some oils like H1R and marine oils in general, which have a higher percentage of heavy oils due to the high load outboards are operated under, can and will influence combustion negatively requiring jetting adjustments.
To me a good oil burns cleanly and has minimal effects on combustion. Film strength is a bunch of gack, especially with a low tech saw motor.
With that said with my bikes I will run a castor syn blend when going to the dunes as it makes me feel better given the very high load and since your essentially wide open all day long. My exhaust actually turns blue all the way to the stinger when duning. Then again your talking a 250cc bike making 50+ HP and a 500 making 60+ HP.
cedarshark
Addicted to ArboristSite
Thank you.
Trx250r180
Saw polisher
I bet you go through a lot of melted boots with a pipe that hot ,blue to the stinger is pretty lean .
Boots are leather line in the inside of the leg. I always increase the main jet two sizes when duning, so it's not lean. This particular bike falls on its face when it's lean on the main jet and it also detonates very easily. As such if your tetering on the edge it's apparent.
Trx250r180
Saw polisher
I would fatten the needle too
I was just using my fuel usage times with my 660 which is around 15 minutes a litre WOT then I added 20% if he has got a more fuel efficient model.
thansk
I do cut & sawmill timber for a living, time yourself for a tank of fuel WOT & you will discover why you're over estimating.
ta
