Kt 100 power

hi guys and gals, I have a spare kt 100 and I would like to get more hp out of it. I am not going to race it, just going to hot lap it. please let me know what would increase power. thanks, chuck

Pipe (DD87) and an EC Birt methanol carburetor.

thanks charles, how much power do you think a methanol kt 100 would make. thanks , chuck

I am no expert, but I thought the RLV pipes made to be used with a high engagement clutch (L4) produced more power than the DD pipe.

I am not an engine builder, but I am not sure alcohol itself will make more power. I think it just allows it because it runs cooler. As a result you can bump up the compression as a result get more power. So I think alchohol, carb change, and more compression. The carb has to support extra flow rates that alcohol requires.

thanks charles, I was looking for some kind of direction. methanol sounds cool cause I,ll get a carb and raise the cr. and that will do it? chuck

How’s this engine setup now and how much are you willing to spend on this experiment?

Even if you manage to find parts used (there’s not a big market for open KT stuff) you’re still probably looking at $300-400 to get a carb for alcohol / fuel pump / pipe / header / flex and then you need the knowledge to make them all work together which isn’t going to be readily available these days.

Factory walbro won’t pump enough fuel to support alcohol so you are relegated to “traditional” fuels if you stick with the Wb3a

Any other changes to help power are going to require machine work. Cut more material off the piston skirt, raise the exhaust port, cut the head depending on how much it may or may not have already been cut, IF you raise compression and put a proper expansion pipe on it you need to decrease timing if you’re running pump gas.

Finally you have to consider how much power the clutch can handle. May need to go to wet clutch instead of dry clutch to keep the clutch happy at higher power levels.

Ultimately you could make a pretty wicked KT if you wanted to but your support for that configuration will be pretty limited and more than likely it ends up being more of a headache than it’s worth. If you’re looking at long term time / value equation I bet you’re better off getting a used VLR and running that for lapping.

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What’s your budget and what tools\machinery do you have access to?

Best bang for buck to to use up to 6% nitro if you dare. Better back off on the timing though.
If you’re patient you could probably grab a used non-evo Rotax for $1200. Good platform for lapping.

The dirt oval folks know a bunch about souping up engines. I wonder if they ever got into the kt100. Probably not, since they tend to use monstrous 4-strokes.

Solid advice to go with a Rotax non-evo or VLR. Then you won’t have to lug around an external starter and find someone to start you when you are sitting in the kart.

I bought an Easykart engine for practice purposes years ago but when it went poof this year, the local engine shops did not want to deal with it. Looked like a crank problem and they said it was not worth it to fix it. I am pretty sure they were right.

thanks guys, what great responses. andy, great points on using different type engines. paul what is a non-evo rotax? are any of the older rotax engines ok? I guess im looking for 20 plus hp. when I raced I had a parilla rotory valve and later a blueprinted kt 100. so I have driven 20 some hp. but not for many years!!! thanks for all the info. chuck

I think that would do it. I would be looking for 8 cc of combustion chamber volume. As everyone below me says, I would check prices on the pipe, carb, and machine work and compare it to buying the cheapest old Rotax you can find, they have 28 horsepower and run on 91 octane gasoline with a little Motul or Rotax XPS.

Even if compression isn’t raised you will typically find a 5-10% gain going from gasoline to methanol. There are four effects: a chemical supercharging effect from more energy being released per kg of air brought in, a charge cooling effect during evaporation which is especially useful if you’ve got an intake restrictor or undersize carburetor to deal with, an evaporative cooling effect on the crankcase, and an increase in detonation resistance allowing higher compression.

They will if your clutch will tolerate both higher engagement speeds and increased torque output!

hi guys, I have a l&t wet clutch so Im hoping that will stand up. so do I need a fuel pump to do methanol. chuck

You’d need a different carburetor or a double-pumper kit for your carburetor as the volume of methanol you’d use is nearly triple that of gasoline.

If you’ve run an open rotary, the care and feeding of a Parilla Leopard will be pretty easy and those engines are nearly free now.