Mix Ratio Question

[BigGreenMachine]

Going to run 80:1 or possibly 100:1 in my KX500 and would like to know before hand if I have to rejet since the original ratio was the stock recommended one.

:Bounce

[200x Basket]

you may have to rejet but i would reconsider the ratio. i know SOME oils can be run that lean but it will cost you horsepower. on my cr500 page there have been several dyno runs and they all lose HP when going that lean. in fact the most HP was made at 16:1 but the plugs kept fouling. i run at 32:1 and have good results with it.

why would you want to run 100:1? i jsut do not see much benifit from it. you may use less premix but you will wear the parts out faster.

[BigGreenMachine]

Burning oil is what creates the most heat during combustion. Run less oil to lower temps, cleaner parts like the powervalves and I would think gain HP.

Its not about running less premix, I'm not cheap Xbasket.

[200x Basket]

actually in the dyno runs the oil COOLS the engine by reducing friction. that is why the HP numbers were up. i just encourage you to do some serious research before you do this. i know the "in" thing to do is go lean but if you ask the guys racing every weekend they are not running 100:1 for reason. 32:1 and 40:1 are the picks. it is a good balance between fouling plugs and making the HP.

just research it on some 2 stroke boards before you do it.

[200x Basket]

CHEAP? pre mix is EXPENSIVE :)

[BigGreenMachine]

32:1 would be a lot of excess oil in the case of synthetic IMO but hey I need to research this further.

XBasket, can you put me onto a good twostroke forum?? Aside from E2S that is,,,

[200x Basket]

http://www.cr500riders.com/cgi/yabb/YaBB.pl

you are supposed to have a cr500 to post on there but you cna read all you want.

[Billy Golightly]

www.planetsand.com is by far, the most technologically minded 2 stroke forum and I've learned so much from there its amazing. Go to the ATV 2 Stroke section and checkout the Amsoil thread in there right now with this exact discussion. Evidently, up to 8:1 with dino oil is where its at for peak hp, and bearing longevity.

[deathman53]

I read on another site that most power from 96? yz250 came from a 16:1 mix, but fouled alot of plugs, fast. 32:1 or 40:1, 50:1 would be the leanest I would go.

[Billy Golightly]

To a certain point (Probably 8:1-10:1) I think you can compensate for the extra oil with jetting and spark plug heat ranges. I know of one guy here that builds flat track 250R motors and he told me mixes everything 20:1 and uses a 7 heat range spark plug.

[BigGreenMachine]

The way I've always seen it was synthetic was a better protector vs dino oil so you could run less to achieve the same effect.

Now it would seem that synthetics high burn point robs power (because it takes more time to burn off?) but still protects better?

Kinda confused.

I want synthetic to keep my exhaust valves clean and to prevent wear but is it really that bad compared to dino oil?

Is AMSOIL really that poor of a product?

[SWIGIN]

i always ran yamalube r at 32-1 in my q-racer and never had the power valve show ware or get junked up

[Billy Golightly]

I had for a long time been under the impression that synthetics lubricate better then dino fuels also, and I think they do but heres the catch. A synthetic, lubricates better while its still an oil. BUT, when it burns, it pretty much disenegrates, as in its lubricity is gone also and theres nothing left. Castors however, when they burn, leave an ash and a residue, that actually help lubricate parts and pieces even though its already been burnt. I've ran Blue marble 50:1 in my stuff for years, and the theory behind it is similar, that it builds up a coating of sorts on parts that does not burn off so its working on a similar principle to what castors do, but with the better lubricity of a liquid that synthetics have.

As for the quality of Amsoil, the guy that I was talking about above that ran 20:1 with a 7 heat range plug, thats what he said they ran, so I dunno.

[BigGreenMachine]

Interesting. Going to have to get my hands on some Klotz Benol soon as my 3L of Interceptor is burnt.

[ccdhowell]

I have no personal experience with Amsoil 2-stroke oil, but have used their other products for autos. All I can say is great stuff. I'd trust anything with the Amsoil name on it to do what they claim it does...period.

Over on another board,http://theoildrop.server101.com/forums/ubbthreads.php?Cat=0, know as Bob Is The Oil Guy, a forum dedicated to lubrication, they really like the Amsoil Dominator, as well as the Mobil One Racing 2T. I've been thinking of trying it, a local shop started carrying Dominator recently and it should really be a good oil.

Amsoil make a 100:1 special premix oil for that crazy ratio if you want to give it a try.

Keep us posted on what you do and the results. I've always been a little nutty when it comes to oil, and the 2-stroke variety is especially interesting.

Chrsi