Fuel Mixture Oil to Gas Ratio Help!!!!!

rogergendron

New Member
Joined
Sep 2, 2013
Messages
11
i have over 2000 miles on my rebuild running it at 40:1 full synthetic 93 octaine nkg b5hs plug stock ignition wth cap removed and hardwired to plug. i ride to and from work every day. its a 20 mile round trip.

using pro mix from lowes or true fuel 40:1 pre mix been working great and is the sweet spot for my build. i work at lowes so promix is easy to get and when its night and i need gas but the stations on the way home are closed i buy true fuel pre mix 40:1 32oz before i punch out for the night .

16:1 and 20:1 with the recomended oil on the stock motor was smoking like hell and had no power also it was wasting gas by not burning it all with the cheap supplied plug. and fouled up my motor pretty badly in only 150 miles !

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pics are before i modded the exauhst and extended the intake ...
 


relaxxx

Member
Joined
May 2, 2008
Messages
97
Now that my bearings are shot to hell, I can hear loud and clear the difference oil ratios make; 40:1 - motor is screaming bloody murder after 10 minutes. 30:1 - Motor sounds like a hammer drill after 15 minutes. 25:1 - not too bad, gets slightly louder after 30 minutes. 20:1 - purrs like a kitten, never acts up.
 

Fabian

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Sep 8, 2009
Messages
4,522
I have had good success with 25:1 for most of my riding duties, but when i'm doing serious (low speed) heavy haul, i switch to 20:1 and adjust the air/fuel ratio to suit.

Typically i get 4,000 kilometers (2,500 miles) at 25:1 before the chrome plating is completely worn away at the upper part of the cylinder; running the cheapest air cooled specification 2-stroke oil i can find.
I have tried using 35:1 but cylinder wear was significantly increased under the conditions my engine is subjected to.
 

JustinJHCSchubert

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Joined
Oct 29, 2014
Messages
13
Liters to Gallons By Volume 1000mL/1L 1G=11.4L

No. say you have a Measurement of 32:1 to solve for =X all you need is to have a known Quantity 1L=1000mL so 32\1000= 31.25 mL of Oil to the Litre Remember your out of 100% of a given Volume of liquid so to be on the safe side you Increase the Oil Volume by 10mL and a full US gallon is 3.8 Litres that is 3.8*1000=3800mL just move the decimal right three places so your Oil In ml for a US Gallon is 32\3800= 118.8mL now I know that looks quite High but your Only adding 31.25mL/1L by volume. that is Only less then Half a Litre of Oil to a Full US Gallon. so If you want to Increase the Oil Volume by 10mL its 31.25+10=41.25mL which is 31.25mL+10mL=41.25ml/L at 3.8L that is 3.8LX41.25mL=156.9mL to 1 US Gallon:D
so the formulas are 32:1 you go 32\1000=31.25mL X 3.8L =118.8mL
or 16:1 16\1000= 62.5mL X 3.8 = 237.5mL see the Oil volume Changes with the expression ratio.
or you could just do 16 X 3.8L and get 60.8mL :rolleyes: but you would Have to Know How many Litres you Had to Begin with:D

Sorry Had to correct my Figures I had the wrong L/G
 
Last edited:

Fly1

Member
Joined
Nov 30, 2014
Messages
100
Thank God no 100-1 post are here like other places.Bud there is a ole saying.I never saw anyone
hurt a two stoke running too much oil.I myself think 32-1 is fine on these engines running below 9000 rpm.
Above that 20-1 to 25-1.Just me, I ran racing Karts for years & we ran 20-1.But they run 15000 rpms
at that many RPM.Above that we ran 16-1 up to 20000 RPM.

Fly
 

Fly1

Member
Joined
Nov 30, 2014
Messages
100
Fabian I got attacked on another form for my options on using more oil.Those guys even the moderators
jumped me there a 100-1 bunch. Oh well free speech here, got to love that.

Fly
 

Fabian

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Joined
Sep 8, 2009
Messages
4,522
I got myself banned on the other forum for presenting well researched information on why you "do not" run the Chinese 2-stroke bicycle engine at ratios above 35:1 when in normal operation, and you do not run the engine above 25:1 when it's working hard.

I was constantly being told that Opti2 @ 100:1 was "good" for the engine, and i kept telling those morons "incessantly advocating 100:1" just what kind of morons they were.
 

butre

Well-Known Member
Joined
Dec 2, 2013
Messages
2,499
Now that my bearings are shot to hell, I can hear loud and clear the difference oil ratios make; 40:1 - motor is screaming bloody murder after 10 minutes. 30:1 - Motor sounds like a hammer drill after 15 minutes. 25:1 - not too bad, gets slightly louder after 30 minutes. 20:1 - purrs like a kitten, never acts up.
oil is more viscous than gasoline, it's the viscosity making your engine quiet down. if the damage is done it doesn't matter what kind of oil ratio you run
 
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