What would you recommend?

alvin l nunley

Premium User
It may be some comfort to know, in 50+ years of karting, I've almost never seen somebody who has learned this sport in less than a year, let alone with their first try. I think it took me about 4 years to get good at it. I'm a slow learner. lol
 

flattop1

Dawg 89
I can run a fully built 131 Sudam or a 250 cheaper than an open modified 14.5, and have twice the reliability and HP with half the maintenance. More strokes = more problems! Ha
More strokes =more problems! Ha .
No ; just less power strokes .;)
More bang for your buck .
4 stroke 2 revs per bang - 2 stroke 2 revs 2 bangs.
 
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Jim46

Member
First thing is you through away the setup sheet for most chassis
Shorten your flex or a higher end pipe will help the tire spin ( farther from the corners)
 
Just keep in mind, shorter flex, more heat. More flex for bottom end and less heat, less for more top end at the price of more heat. However temperature is almost a non point for H20 motors, even on gas. If you’re sticking a piston on an H20 motor and think flex length is to blame... you have bigger problems.
 

alvin l nunley

Premium User
Just keep in mind, shorter flex, more heat. More flex for bottom end and less heat, less for more top end at the price of more heat. However temperature is almost a non point for H20 motors, even on gas. If you’re sticking a piston on an H20 motor and think flex length is to blame... you have bigger problems.
2 short, what ever that is for the pipe you're using and the engine you're using, can cause the engine to go lean. Been there, done that. It's my experience; pipes have a "perfect" header length, that length can change plus/minus a quarter-inch very safely, much more than that and you start running into less performance and/or a lean condition. If you have no information on that perfect length, practice laps will help. You have a stopwatch right?
 

rainman

Premium User
Kt 100 is about as easy as anything .
The other spanish, italian et all piston ports would be a close second except
Parts avalibility .
A small 100cc reed jet isnt much more then a kt .
Now if you need a legal class engine thats a little more involved , though not improbable .

to my knowledge they didn't make any piston port air cooled engine for karting in Spain that I know, at least not from the 80s/90s. Only manufacturer was Arisco/IDK and they did build good reeds and rotaries. Maybe othe Hispanic or South American countries did, like Riomar in Brazil, but I don't know. Good 90s or early 2000s JICAs sell cheap nowadays though.
 

Komet99

Member
Bigger gear on the axle. Pulls power from the motor and lessens rpm. I used to do that on wet tracks and no one could figure it out. People watching over the fence said they could hear the difference.
 

rainman

Premium User
You can get some open 2 strokes cheaper than open and limiteds 4 strokes, but once not stock there is no racing engine you can consider completely as reliable. A 125 Sudam is reliable, a stroker 131 is pronecto have issues if you don't have much experience with 2 strokes and even if you do. Very fun, though. IMO the best engine I have tried or owned on a kart is the Aixro XR50 aka Wankel. Reliable, fast, best combination of the torque of a 4 stroke and top end closer to a 2 stroke, a perfect power curve... Now by cc/power the last generation KZ shifters are beasts, like my Modena, but very hard to drive unless you spent many hours at the track learning how to get the best when shifting. There is an electronic shift system with padfles that removes the need to tske your hands off the wheel to shift and cuts the ignition long enough when shifting so you don't need to raise your foot from the throttle pedal either. This small 125 cc can outrun most 250s but I would love to see someone able to get the power of a twin cylinder 250 Superkart engine to the ground on a dirt track. The moment that happens there won't be any more discussions about 2 or 4 strokes or whatever.
 
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