Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: Braap257 on July 30, 2010, 08:30:44 AM

Title: The best way to get the right Premix ratio??
Post by: Braap257 on July 30, 2010, 08:30:44 AM
Okay so as you guys know I just got my YZ250. And the old gas thats been sitting in it has almost been used completely. So I will be needing to make some Premix for the 1st time soon. I am gunna pick up a new regular 5 gal gas tank from the store soon and I am gunna use Bel-Ray 2 stroke oil "As that is what the guy used before" and He said he mixed it 40:1 so im gunna do the same. but my question is with these regular gas tanks how can you get an accurate measurement to make sure the ratio is right?
Title: Re: The best way to get the right Premix ratio??
Post by: JETZcorp on July 30, 2010, 08:39:41 AM
Well, it's just a little bit of math.  I'm assuming you're going to mix it in the 5 gallon can, so just figure out what 1/40th of 5 gallons would be.  I can tell you just from memory that one quart to five gallons makes 20:1, which is what my uncle uses because he doesn't believe in synthetic oil (and barely ever rides so he can afford it!).  If you want half as much oil for a 40:1 mix, then simply use half a quart of oil to five gallons of gas, and you should have 40:1.

To check and make sure this is right, let's look at it another way.  One quart is equal to 1/4 of a gallon.  Half a quart is 1/8 of a gallon.  1/8 of a gallon of oil, divided by five gallons makes 1/40, which is the ratio you were looking for.  So we know our previous number was accurate.

Half a quart (16oz) to five gallons.
Title: Re: The best way to get the right Premix ratio??
Post by: Coop on July 30, 2010, 08:40:30 AM
http://www.dansmc.com/pre_mix_ratios.pdf (http://www.dansmc.com/pre_mix_ratios.pdf)
Title: Re: The best way to get the right Premix ratio??
Post by: GlennC on July 30, 2010, 09:15:44 AM
1 Gallon = 128 Oz.
128/40 = 3.2 Oz. per Gallon

When You know how many ounces per gallon (40:1 = 3.2 Oz Per Gallon) It is easy to calculate for any amount of gas.

3.5 gallons X 3.2 = 11.2 ounces of oil for 3.5 gallons of gas.
Title: Re: The best way to get the right Premix ratio??
Post by: Braap257 on July 30, 2010, 10:08:17 AM
Well, it's just a little bit of math.  I'm assuming you're going to mix it in the 5 gallon can, so just figure out what 1/40th of 5 gallons would be.  I can tell you just from memory that one quart to five gallons makes 20:1, which is what my uncle uses because he doesn't believe in synthetic oil (and barely ever rides so he can afford it!).  If you want half as much oil for a 40:1 mix, then simply use half a quart of oil to five gallons of gas, and you should have 40:1.

To check and make sure this is right, let's look at it another way.  One quart is equal to 1/4 of a gallon.  Half a quart is 1/8 of a gallon.  1/8 of a gallon of oil, divided by five gallons makes 1/40, which is the ratio you were looking for.  So we know our previous number was accurate.

Half a quart (16oz) to five gallons.


Sweet! Thanks JETZcorp! The stuff the previous owner was running was 100% Synthetic bel-ray. Can i switch over to a non-synthetic without any problems???
Title: Re: The best way to get the right Premix ratio??
Post by: TMKIWI on July 30, 2010, 02:25:49 PM
If you can aford the bel-ray stick with it.
If not run Yamy lube.
The better the oil is, the better in the long run for your motor.
Go to a chainsaw shop and buy one of the measuring  jugs.
The more presice the mix the better. Dont guess.
Title: Re: The best way to get the right Premix ratio??
Post by: dogger315 on July 31, 2010, 07:15:34 PM
Quote
with these regular gas tanks how can you get an accurate measurement to make sure the ratio is right?
Very simple, pick up a ratio rite container from this site:
http://www.motorcycle-superstore.com/2/9/205/7411/ITEM/Ratio-Rite-Measuring-Cup.aspx (http://www.motorcycle-superstore.com/2/9/205/7411/ITEM/Ratio-Rite-Measuring-Cup.aspx)
Simple and fool proof.  You can also use it to pour the correct amount of tranny oil
after clutch change or maintenance.

I use it for tranny fills but I have an Accu-Mix container to do the premix.  Here's what
it looks like: http://www.accu-products.com/accu-products/accu-mix-fuel-jug/prod_3016.html (http://www.accu-products.com/accu-products/accu-mix-fuel-jug/prod_3016.html)
Gas goes on one side, oil on the other, then turn the container over and mix, foolproof.

dogger
Title: Re: The best way to get the right Premix ratio??
Post by: JETZcorp on July 31, 2010, 08:42:39 PM
Another easy way to get things mixed without having to look like an idiot shaking a massive 5 gallon can around is to pour in the correct amount of oil for a full can when there's almost nothing in the can.  Then, when you're at the gas station, just pour in your gas (by the way, your bike will want the best stuff they got) and the violence caused by the ridiculous amount of power those pumps have will mix your gas quite thoroughly.  A couple little shakes before you start pouring might help you sleep better at night, though.
Title: Re: The best way to get the right Premix ratio??
Post by: Braap257 on July 31, 2010, 08:50:39 PM
@ JETZcorp. Yes I plan to just put the oil in the bottom and then fill it up with premium. Hopefully the pump will do the mixing for me. And with ratio funnel i picked up today there will be no guessing :)
Title: Re: The best way to get the right Premix ratio??
Post by: riffraff on July 31, 2010, 09:55:02 PM
I use a plastic baby bottle to measure my oil, they even seal tight so you can take a bottle or two with for emergencies
Title: Re: The best way to get the right Premix ratio??
Post by: RideRedMx2 on August 01, 2010, 12:22:34 AM
Just grab one of these and your set,you can buy lids for these also;Just pour the right amount of oil in your gascan first and the filling of the can with gas will mix it for you   ;D


(http://i55.photobucket.com/albums/g136/halfstatue/08-01091.jpg)
Title: Re: The best way to get the right Premix ratio??
Post by: 2T Institute on August 01, 2010, 04:37:11 AM
Thank christ for the metric system. :o
Title: Re: The best way to get the right Premix ratio??
Post by: scotty dog on August 01, 2010, 08:49:02 AM
Thank christ for the metric system. :o



Im hearin ya! All this talk of gallons and quartz and ounces hurt my brain ??? ??? :P
Title: Re: The best way to get the right Premix ratio??
Post by: GlennC on August 01, 2010, 10:53:09 AM
You foreigners, and your fancy round numbers
Title: Re: The best way to get the right Premix ratio??
Post by: JETZcorp on August 01, 2010, 01:48:45 PM
For simple things like this, it's not too bad.  But I can imagine that if I were to take a physics class that wasn't in metric, it'd be hell.