What fuel mixture should i run for a KT100 and what RPM's does a KT100 run at on a 1/5th mile dirt track. Thanks, Allen

is it stock. wat kind of pipe. r u running gas. which carb. those all play into the deciding factors

it is stock it is on alcohol Walbro wb-3a carb, 3 hole can muffler, Thanks, Allen

if it is stock it wont run on alky. the stock kt was designed for gas epecially with the walbro carb from wat i have been told. also if you can convert it to a pipe motor and it will be faster.

i will check on the carb thing. I can run gas if i need to. or do i need to get a different carb and if i do what do i need. i cant switch it to a pipe thats the rules. It is on a junior sprint not a kart. Thanks for all the help. i really appreciate it. Allen

Stock, a 3 hole can, a WB-3, on alky??

Wow, that's a whole lotta stuff going wrong all at once.

Alky is doing nothing for you except causing headaches with that carb and muffler.

Get a gas carb and start from there.

On gas, run 8oz/gallon, no more, no less, don't let the so-called experts tell you different.

3 hole can, get the clutch coming in about 8000rpm, peak rpm can be alot of places, but on a long track you're gonna have to try for 12,500 to 13,000 if you can get it there. Some can motors like low rpm, some like more, just depends.

tom, can u pm me your phone number so i can talk to you and get this figured out. Thanks, Allen

What is the best oil to mix with alcohol for a Yamaha and does the ratio differ from gas/oil mixing?

A stock Walbro 3B-A carb will not work with alky with out extensive modification Buller offers 2 that will. The oil mix is the same for both fuels,a min. of 8oz. ea. but I'd recomend Blenzol Green label with alky and Red line synthetic with gas.

I have a alky carb off my kt, switched to gas and never looked back. I'm going to get hammered for this but I don't believe there is any thing to be gained with alky on a 2cycle.

All things being equal, alky makes about 10% more power than gas. It's all in the tuning.

Jeff,

No hammer involved here... I'll try to be gentle.
An IKF/WKA legal KT100 is about 2 seconds a lap faster on a 2 minute enduro course using a mix of 30% alky/70% gas compared with 100% gas. I know this for a fact as I ran a whole race at Riverside, Ca back in 1983 running that mix just to prove it was faster and I could get it through tech. No, I'm not going to share the information on how I got it through tech. Also, a KT100 Walbro carb will easily pass enough fuel to run 100% alky without any internal modifications other than to remove the flaps from the pumper. The key is outfitting the kart with a stand alone fuel pump just as used by the shifters. The Walbro internal pump can't move enough fuel but the jets are big enough if the needles are set at something like 2.5 on the low and 2 on the high. On a 35 second sprint track the change from gas to straight alky reduced the lap times by a solid one second. Again, the information comes from my own personal testing. Many people in karting wrongly believe that alky only improves performance if an given engine is modified with higher compression and more advance on the timing but it just isn't true. The best example I can offer comes from the good old days of running McCulloch engines in the "stock" reed classes. The rules dictated that the motors be left in the stock condition yet it was simply impossible the win a race with a Mac running gas.
The only question was how much alky.... the stock carbs fell just short of being able to deliver enough fuel in most cases. But if you had a setup that would handle the fuel you were going to be fast. I won my first try at the IKF sprint National in 1971 driving for Walt Meyers/Meyers Speed Shop and we ran 100% alky but it was edgy.
These days I play with the Leopard and testing with the fully legal Leopard I have found that the package will handle 40% methanol with ease and tune very easy. The lap times improved in my Leopard test by just short of 1 second on a 50 second track.
Bottom line... two cycle engines love alky!
Steve O'Hara

Thank you Steve, you've provided me with my learning thing for today, I figure that at 71 If I can learn something new every day,I'm ahead of the game, thanks again. Jack....

Hmm, no one told my bored WB3A that.........
I run one on a Parrilla TT27 rotary valve on alky, on a sprint track, and it did just fine (100% menthanol).
The throttle was bored to 1.187", and I forget what the venturi size was, I would have to dig it out of storage.
All I did was install the alky kit that was floating around 15 years ago.
Most likely I had opened up all the passages in the pump section, since I do that to any alky conversion I have done.

I just started running with alky and Isn't one of the other reasons is that it makes the engines run much cooler and last longer?Thanks for any input. Howard

Howard,

Yes, you are correct... the basic power producing advantage of alky is the cooing effect from a much lower vaporization temp. The result being a denser charge in the combustion chamber. The chemical itself has less BTU per pound than any gas but the shortfall in energy released is overcome by the greater amount of fuel required for a proper air/fuel mixture. To burn properly you need close to double the amount of fuel mixed with the air when comparing alky with gas. The cooling effect of twice the liquid with a lower vaporization point is dramatic and will result in a typical two cycle kart engine being cold to the touch on the intake tract and case while running at full power for extended time.
The fact that we run the same amount of oil per gallon of alky as we do in gas means that nearly twice as much oil moves through the engine for a given period of running.... all that extra oil protects the moving parts from wear and heat.
Without a doubt, alky is much better for the motor due the extra lubrication, cooler operating temps throughout most of the engine and it's extremely high resistance to detonation.
I don't know why it isn't the ONLY fuel used in karting!
Steve O'Hara

Steve Do you know if there's any difference in using a conventional 34mm carb on alky compared to an attomizer 34 mm alky carb? Thanks Howard

And yet you do get detonation running alky. At least I did running it in my Mc91 and Mc101. It was explained to me that perhaps it's the oil detonating. What do you think?

I did notice that the pipes run cooler with alky, compared to gas.

Howard, I know your question was directed to Steve but just a little something I experienced on the track and not just on the dyno. Many years ago Mike Colver converted 34mm Mikuni pumper carbs (aka: Colverators) to atomizers. On the dyno the advantage was minimal as far as the numbers go but they did provide a more "crisp" throttle response and were far more forgiving when used on my twin (open K-88's). I think today's atomizers really depend on the person who converts the carb as to how well (or if) it increases performance. But I can say the Colverators were great carbs, very consistent with adjustability. I do not recall anyone having anything bad to say about them. Now, with today's conversions to atomizers I've heard good & bad. I do not know what the differences are today. (??). Al

Al,Thanks for the response. Any info is always appreciated. I have a couple Buller Makuni attomizers that I run on Mac-101's and it runs great.I was having trouble with my LMR as far as tuning,but it turns out it might have been a problem with the engine,when it was converted over to run on alky.I will hopfully be giving it another try before winter sets in and see what happens. Thanks Howard