KX100 at a 40:1 mix

[xrkx]

I have been running my wife's KX100 at the normal 32:1 mix with no real loading up problems. Only once did I have to put a new plug in it on the trail. (But is was the original plug too) She does not ride the death out of the bike like I do when I get on it and I was just wondering how many of you out there have lightened up the mixture to a 40:1 and how did it compare?

 

[DEANSFASTWAY]

Bike will run richer . Youll not want to dilute the ratio too far as the crank in that little motor likes its oil . you wont be saving money on mixing oil when you need to replace that crank, its been talked about here before quite a bit. GOOD LUCK

 

[jboomer]

Yeah, I'd stick with the 32:1, it'll only help. But, if she's not riding it really hard, you could probably get away with running a step hotter plug, to help keep it cleaned off. Although, if you've only fouled one plug, sounds like it's pretty dialed in (just as long as you're not running it lean!).

 

[Racer#213]

I run Bel-Ray H1R Fully synthetic racing oil in my kx100 at 50:1. I get great performane, and i have about 80 hours on my top-end. I'm about to do a top-end rebuild though, and i'll get pics of my top-end to see how the 50:1 is doing on it.

The first 20 hours i ran Kawasaki's Racing oil at 32:1.

 

[Motogrl307]

We tried 40:1 with Bel Ray H1R and wasted the cranks. Went back to 32:1 Motul 800 now. I run pretty much wide open all the time and the less oil was a bad idea.

 

[Racer#213]

see, i run trails and arenacross. So i'm in the mid to low quite a bit. i do get her reved out quite often, but not for long periods. Unless i go to my friends, i might hop on the dirt road and top it out, but not a lot, and i never rev it too long.

 

[xrkx]

I will stick with the 32:1 mix. I was just wondering about the 40:1 mix because I had heard it mentioned before and I was just wondering if it was a bad idea or not. I would rather have to change a plug every now and then than have to do a complete rebuild because I skimped it on oil.

Thanks for the info.

 

[frankrock363]

The bike will run a little richer at 40 to 1. Remember less oil means more fuel. More fuel = richer. Contrary to popular belief that means there is more chance of her loading the bike up. But my girlfriends 2000 kx100 gets mixed at 36 to 1. Bone stock,pump gas cruising at a constant 1500 RPM with no problems.

 

[Racer#213]

wait wait wait, the less oil to gas is richer? I always though it was leaner? Am i ass backwards here?

 

[KXaggerator]

I run Amsoil 40:1 in my KX310 and KX500 for the slight added fuel range (less oil/more fuel), but I also only run leaded F&L race gas which runs cooler. I am a desert, HS & enduro person, not a motocross guy. My 1990 KX500 still has the stock crank and the main bearings are six years old (I replaced the bearings because I thought it was time)and I have never had a mechanical stoppage on either bike, not even a fouled plug. My chain saws also run 40:1. In fact the Husqvarna Rancher 55 recommends 50:1.

With all that stated, I would recommend that you stay with 32:1. I just wanted people to know that just because you run less oil your bike will not suddenly explode under you, but I do re-jet often to meet the conditions where I ride.

 

[racer 187x]

I race with the 40:1 in the desert here in Utah and Nevada. There haven't been any problems with my bike and we run races from 2000 ft to 7000 ft. Plus the Motul 800 works great!

 

[xrkx]

Those bigger motors, 250's and larger, don't turn up the same kind of RPM that a little 125 or 100 or 80 do. So they can get away with less oil. When I was little younger, I rode a KX250 for 2 years at a 40:1 mix. Never a problem. I also rode a KDX200 for 3 years at 40:1. Also never a problem. But.....I have also always let all my bikes warm up completely before ever taking off on the trail too. That DOES make a big difference in the life span of a motor.

On the oil subject: The less oil you put in your gas means the more gas you have entering the cubustion area. The more gas you have, the richer it will run. Oil is not really considered a burnable item. Gas and air is. So if you want to think of it like this, take oil out of the equation and just look at it as two parts, gas and air. If you ad more oil, you are putting less burnable gas into the motor. So it will run leaner.

If you put to much oil in the gas, you are decreasing the amount of gas and the ratio of gas to air can become to much air to fuel. This means a lean condition.

Or you could just take my word for it. To much oil can result in a lean condition if the motor is not loading up from to much oil first. To little oil can result in a rich condition if your motor does not lock up first from lack of oil.

 

[Racer#213]

ok ok thanks for clearing that up. Well we tore the top-end apart yeasterday, an everything looked great! i may need a new piston, but it looks good. Some carbon on top, but no scoring or burned.

 

[xrkx]

If you are have a lot of carbon build up on your piston and rings, go to Yamaha Outboard shop and get a bottle of "Yamaha Ring Free". This stuff works great. You mix it with your fuel. Just follow the directions on the bottle for mixing. It takes very little for a constant treatment.

What it does is clean off any carbon build up that you have on the piston, head and rings. If you continue to use it, it will put a coating on those parts and help keep more carbon from being able to stick in the rings. Carbon in the rings is a big problem for outboard motors. I run Ring Free in my bikes, boat and cars.

 

[Racer#213]

the dealer said that, since it was like a smaller circle int he midle of the piston that, that means ti'm getting good airflow. But that does sound like some good stuff.

 

[xrkx]

In outboard motors, cheap oil (out of gas stations and places like that) are the leading cause to carbon build up and leading to piston failures. Also old and cheap gas too. I have run Ring free in some of the bikes that I have torn down just to see what it looked like and the bike that I ran it in all the time was clean as it could possibly be. That sold me on it. It is good stuff and it really does work.