A premix question...

[jjcobra99]

A premix question... **UPDATE** Answer from Amsoil tech

This may have been asked before, but I didn't see it. I have an 03 CR250 bone stock. Using Amsoil series 2000, what should my mix ratio be? Owner's manual says 32:1, Amsoil says 50:1. Also do I need to make any adjustments to run this oil? I'm not racing, and I would like my motor to last a while. Thanks!

 

[Jaybird]

You will be fine in the 32:1 range, pay no attention to oil mfg recommedations.
You will need to jet the bike for that ratio at your elevation, temp, relative humidity, fuel type, and riding style.

 

[The^^Rock]

Yep im in same boat as you, 03 CR250.

Running 32:1 :thumb:

 

[jjcobra99]

Found this in a write-up by Eric Gorr, now I am even more confused about what I should do. Here is a quote:

Pre-mix oils are formulated for a fairly narrow range of pre-mix ratios. You should examine the oil bottle for the oil manufacturer's suggestion on the pre-mix ratio. All production two-stroke dirt bikes have a sticker on the rear fender suggesting that you set the pre-mix ratio to 20:1 That sticker is put there for legal purposes. Always refer to the oil manufacturer's suggestion on pre-mix ratios. In general, small-displacement engines require a richer pre-mix ratio than do large-displacement engines because smaller engines have a higher peak rpm than larger engines. The higher the engine revs, the more lubrication it requires.

Here is the link to the whole article. Tell me what you think. Thanks!

http://ericgorr.com/techarticles/carbtuning.html

 

[b-b00gie]

I would have to disagree.


Your bike manufacturer makes a suggestion for a general premix ratio (typically 32:1). I think it is incorrect to follow this recommendation over the recommendation of the oil manufacturer.

The bike manufacturer makes a general statement to try to cover all brands of premix, from very generic oil to high performance oil.

If a company such as Belray or Amsoil makes a specially formulated oil which they specifically recommend running at 40:1 or 50:1, this is the ratio you should run. If you do not you will not break down and burn off all the oil in your mix.

I use Belray H1R premix which they recommend at 40:1 mix and that is what I run.

Just as Eric said, you should ALWAYS follow the oil manufacturer's suggestion for *their* product. An oil manufacturer would not suggest you run a ratio that is dangerous for your bike. Remember all oil is DIFFERENT.

 

[Jaybird]

Originally posted by b-b00gie
I think it is incorrect to follow this recommendation over the recommendation of the oil manufacturer.
The bike manufacturer makes a general statement to try to cover all brands of premix, from very generic oil to high performance oil.

And the oil mfg. knows what 2-stroke machine you are putting the oil in? And, what is high performance oil and how does it differ from generic type?

...If you do not you will not break down and burn off all the oil in your mix.

Please go into more detail on this.

An oil manufacturer would not suggest you run a ratio that is dangerous for your bike. Remember all oil is DIFFERENT.

And a bike mfg. would? Oils are different, but bikes are the same?

 

[Rcannon]

I think th eoil people are looking at a different book...They charge big bucks for their products. Suppose they print on th ebottle that their products are good at 64:1. As a customer I can now justify buing their product. After all, I use half as much. The cost drops a considerable amount. Personally, I see too many mechanics using Yamalube R at 32:1 to ignore it.

 

[viking20]

Guys,if we just want to ride,and not experiment with high or low mix ratios,lets go and buy ourselves a can of oil,preferably not one of the cheapest .Next,lets mix it like most people do,33-1 or in my case 40-1,forget about it,and ride!

 

[b-b00gie]

And the oil mfg. knows what 2-stroke machine you are putting the oil in?

Apparently so if 99% of 2-strokes should be using 32:1, then they are all the same right? ;)

And, what is high performance oil and how does it differ from generic type?

"Generic" oil is what bike manufacturers make their suggestion on. These oils are mineral oil and vegatable based oils (petroleum and castor, respectively).

Oil manufacturers such as Belray, etc. produce synthetic ester based oil. These oils contain chemical additives which are not found in generic oil. These additives offer more lubrication, keep the oil from breaking down, etc... The chemical properties of these engineered oils require a different premix ratio. If you choose to ignore what these companies research, create and suggest, that's your own choice.

Please go into more detail on this.

Please see above. Also, more oil in the fuel makes a thicker fuel mixture which will travel through jets slower.

And a bike mfg. would?

No. I never said that. The bike manufacturers are making a very broad statement in saying that almost every single bike should be run at 32:1 no matter what type of oil you use.

What I stated is that it is safe to follow an oil manufacturer's recommendation to run a different ratio. The companies research their product and know what ratio you should run their *synthetic* oil at. What business angle would they have to suggest something that may damage your bike? None.

Oils are different

Now we're talkin!! :)

, but bikes are the same?

A Honda 125 or 250 is more similar to any other brand of 125 or 250, than a mineral or castor oil is to a synthetic ester oil.

 

[jmics19067]

I believe that there are way too many variables too come even close to be able to make a well informed decision without any experience in the particular application. If you find something that you like stick with it ,if you find a problem try and figure it out ,then guess which direction you need to go.

I am assuming < and you know how to break assume down> that bike manufactures build there bikes with the idea of an average rider using an average oil. Then I also assume that average oil manufactures figure you are going to be putting it in an average engine and putting average loads on the engine. But if you read the bottle of oils there are different oils for different applications, take a look at some castor oil and it tells you 20 to 1 in high rpm racing engines only, take a look at some hardware store oil and safe at 100 to 1 for your weed whacker. And everyone wants to make sure that they are protecting their own butt for when certain things just don't line up the way they should and yet somehow tout their stuff at being the best that is out there.

High heat, high rpm, and high loads recquire more oil for it to do its job correctly. If you are racing an 80cc in the expert class up sand hills you are going to recquire more oil than a guy that is idling his 500cc bike down a hard pack hill for adequate protection. This is probably the hardest fact that you can rely on in this general topic unless someone who is a lot better at being a mechanic than me knows how you ride ,where you ride and then tears down the motor and inspects it.

In my wacky opinion oil ratios are along the lines of octane ratings of your gasoline. Too much is basicly a waste but too little and you waste your engine. So too err on the side of caution for your needs may hurt the wallet a little every time you go riding but it wont hurt your wallet big time and you can't go riding until your bike is fixed.
Making sure you are jetted correctly for whatever your conditions are plays a vital role also.

 

[Jaybird]

boogie,
I still stand on my first post in this thread.
If a kid has an 80cc 2-stroke and goes out and buys an oil that recommends a ratio of 100:1 and he follows that rec. he is making a big mistake, especially if he rides the bike hard.
When you talk "generic" oil, are you refering to LawnBoy specials?

A high RPM bike needs a bit more oil, IMO. Also, there is benefit to running more oil HP wise, if you happen to be concerned with performance.
I realise that more oil will make for a more viscous fluid, but I refer to my first post for my answer to that situation.
I don't recommend anyone go out and change thier ratio to 20:1 without first being aware that there are jetting changes that must take place. If they play ride or trail ride, there may not really be a need for that ratio anyway. But in refference to the guys original post, 32:1 will be fine to use with ANY bike specific oil on the market, as long as the bike is jetted properly for that ratio and current conditions.

 

[WFO]

I read a study (which I can't find at the moment) where various ratios were run on a given bike. The bike was properly jetted for each ratio and run on a dyno. The basic finding was the lower the ratio (IE-more oil), the more power on the dyno. Whether this was attributable to better sealing of the rings, running cooler, or whatever I'm not sure. Remember the key remark here is it was CORRECTLY JETTED for each ratio. They didn't just add more oil.
If anyone is interested, I will try to find some specifics on the test.

 

[r_rider28]

It is a matter of understanding which is the correct oil for your application. A stock 2 stroke 250cc engine rode in the trails can use a petroleum or generic oil at a 32:1 ratio. The same bike rode on a mororcross track at WOT for longer durations might consider stepping up to a synthetic blend or full race synthetic ran at the oil mfgs recomendation. Same bike with porting for top end and higher compression may want to veto the oil mfgs recomendation and use more oil and jet accordingly. Same bike ported for top end and extreme high compression used for sand drag racing or hill climbing may want to consider running a racing caster oil at 32:1 ratio. So its really a matter of using your best judgement once you understand oils and the applications they are intended to be used for. Good Luck

 

[Jaybird]

I buy that 100%, r_rider28.

 

[jmics19067]

It is a matter of understanding which is the correct oil for your application.

HeHe My four paragraph note in one sentence . Oh well atleast my typing skills are getting a little practice.

 

[jjcobra99]

A lot of good points in here! I sent an e-mail to Amsoil tech. I am curious to see what they say about this, and hopefully they can shed some light on the subject. I will post their reply when I get it.

 

[jjcobra99]

Here is the reply from Amsoil tech. Tell me what you think!

Manufacturers generally base their lube spec's on petroleum products. They
also typically factor in a safety margin for possible use of really low
grade products someone may use. Our synthetic 2 cycle oils are formulated
so that we can tell the customer what is going to work the best as far as
protection versus over-oiling. AMSOIL Synthetic 2 Cycle Racing Oil (TCR) is
especially robust product that requires high heat and high rpm's for proper
combustion. You may feel very sure that our products are very flexible as
far as being able to cover all the mix ratios.