Fuel Mixture for kx 100

Spanks is having a few problems, he lives in the area where that massive hurricane hit in florida. Plus his family is going through a rough time. Thats why he doesn't post.

That's too bad. I knew Spanks was havin' a few problems, but I wish all well for him.

Grizzly600 wrote:

moto814 wrote:

lumpy790 wrote:

I have heard/Read this story before but I for 1 do not buy it. That much oil would create more drag from gumming up. = less HP.

Tell ya what... Next time you are in the area, give me a yell, and we'll hit a track. We'll mix up some 20:1 fuel/oil and go for a ride. Let me do the jetting and set the plug. Thicker mixes like 20:1 work better under the more agressive riders, but with good jetting can be made to work for anyone. Most people will be fine between 32:1 and 50:1 tho. Because I'm not the fastest rider, and I tend to ride a more casual pace these days, I mix at 40:1 in my 200. But I would have no problems going to 20:1 for a day to prove a point.

Why isnt there a cloud behind RC, CR, JS & TP ? The factorys shure would do something as simple as that if it gave them more HP.

Simple. They ride hard enough to burn the oil. An expert running the engine under a full load with proper carb jetting will develop combustion chamber temps that will cleanly burn the heavier oil mix.

So why dont the oil manufacturers tell you to use more to get more HP and as a side bennefit they sell more? They don't and since when have the oil companies done anything but do what would make them more $$$ ???

Ever read the series of articles Dick Lechein did for several of the Hi-Torque mags back in the late80's/early 90's? He was pushing EXACTLY that.

-Steve
whats that i smell? It must be a challenge

Yawls ever burn moth balls in yer tank?

spanks was the one who did that test and as Steve said PLENTY of others have done it and the result is always the same, more oil = more power up to about 16-18:1.

I'm running 27:1 without so much as a puff of smoke and I know my bike is overly rich on all circuits. I'm pretty sure I could run 20:1 without any smoke, spooge or gumming up of whatever it is you think will gum up.
As Steve alluded to the ratio you need to run has a lot more to do with how you ride then anything else IMO. I used to run 40:1 when I started out and would always find plenty of oil in the crank when I stripped it down. As I got quicker I switched to 32:1 but when I took my KX and YZ apart recently there was not a drop of residual oil sitting in the bottom of the crank. Sure the crank and everything has a light coating on it but there should have been a lot more. So I'm now running 27:1 (Castrol TTS). I'll strip it down in a couple of hours and see how much oil is down there. I only ride MX now on fairly fast tracks so more oil is what's needed, if I went back to woods riding I'm sure 27:1 would be far too much.
Don't get the idea that 32:1 is some magical figure though, the only reason it was chosen over 33:1 or 31:1 etc. was because of some nice round amount of oil it gave to some quantity of fuel. 700ml of oil in my container gives me 27:1 so that's what I'm on. If necessary, next will be 24:1 because 800ml gives me that

. What I'm saying is you shouldn't really just stick with some magical figure as you get faster or slower or change riding type. 32:1 wouldn't be a great ratio for a trials bike, or drag racing, or desert racing, or a pro on a 125 or a woods rider on a 250 etc etc. Keep an eye on the residual oil in the crank when you lift the cylinder off, you're looking for a puddle of oil at a depth that goes about 1/8" up the crank wheel.

That's good info Zenith.

Very good post, glad to have you here Zenith.

As I am old and slow now I should be able to get away with 200/1

Goatours wrote:

quote]

Yawls ever burn moth balls in yer tank?

burning crushed up mothballs is stupid it raises the octone level up to an uncontrolable anount we did that to a friend of mine chevelle..will NEVER do that again one 1/4 race his motor was toast! so i will not do that ina dirt bike

From the gasoline faq

6.20 Can mothballs increase octane?

The legend of mothballs as an octane enhancer arose well before WWII when naphthalene was used as the active ingredient. Today, the majority of mothballs use para-dichlorobenzene in place of naphthalene, so choose carefully if you wish to experiment

. There have been some concerns about the toxicity of para-dichlorobenzene, and naphthalene mothballs have again become popular. In the 1920s, typical gasoline octane ratings were 40-60 [11], and during the 1930s and 40s, the ratings increased by approximately 20 units as alkyl leads and improved refining processes became widespread [12].

Naphthalene has a blending motor octane number of 90 [52], so the addition of a significant amount of mothballs could increase the octane, and they were soluble in gasoline. The amount usually required to appreciably increase the octane also had some adverse effects. The most obvious was due to the high melting point ( 80C ), when the fuel evaporated the naphthalene would precipitate out, blocking jets and filters. With modern gasolines, naphthalene is more likely to reduce the octane rating, and the amount required for low octane fuels will also create operational and emissions problems.

Anonymous wrote:

Time and time again dyno tests have been done that show more oil in the fuel creates more power. Maximum power is had at usually around 18:1. Kart racers are sticklets for maximum power because of how strict their engine rule package is. If there was an advanage to running 50:1 or 100:1 they would do it in a heartbeat. Go to a kart race and check fuel mix ratios. You'll find that most are at 18:1 to 22:1. There is a reason for that. Power.

-Steve

That's right, every rotax guy at the track runs 18:1. It's so strict that there's only a small selection of jets you can use etc.