Engine Tuning on Track

[Intrepid_69]

Being able to lean and Richen the Engine while driving to keep the engine temp down on KC1, KC3 and the future direct drive Engines. and also choking the airbox? haha

[Sam]

that would be awesome it would be like the brake bias u could get rich or lean on high and low jets

[Intrepid_69]

it would be cool as ae

[Gatto]

Yes...setting of carburettor during the race is very difficult things I want it!!

[Gatto]

Here is our start  in Sosnová... Czech Championships - KF2

[Racehard]

+1 for tuning the carb

And especially choking the airbox for 100cc.
Choking the airbox would be a must for 100cc. Through choking, the engine then should shut down if you do it long enough.

[Hansen24]

Ive been driving kf3 the last couple of years. And i ended up understanding how important fine tuning the carboratuor while driving so +1 for that idea:D

[whitham69]

That something i never got while watching karts on TV, i raced club and national level bikes from 125cc to 1000cc i even help testing with the 500cc modenas GP bike of Kenny Roberts snr and not once did mechanic say to me block the air in take, we change maps on the 1000cc superbikes(injection) and added restrictor or differant reed valves jets needles to intake mainifold/carb, are these motors under tuned or something as that would wreck highly tuned 2/4 stroke running it lean like that unless the top and bottom are not set at optium tune, we rebuild the motors ever 700/1000 miles on the 2 strokes.Back in the days of no motor limits you set them so lean for max power that they would siezed or blow as they cross the finish line,  i only tryed the kiddy karts you get given at places like chedder gorge so im nieve to the engine tune these karts have. i understand why it done but not why it needed to be done.

[EVO]

Carburator adjustments are essential.  First you get a baesline setup for track altitude, turns, and length of straight. 
During practice you will run rich to preserve the engine,  during qualifying you'll run a little more lean to get the best performance but you could risk exploding the enigne.
This is why you have your eye on the cylinder head temp, exhaust temp, and water temp.   If you can still squeeze a little more power out youll adjust the carb while driving.   

Aircooled enignes are very senseitive to carb adjustments.  Back in the day during the Formula A the racers all had thier right arms on the carbs to get the best accelration off the rolling start. This is why you see plumes of smoke the karts are rich at the low end. 

This is done in karting becuase it is fairly easy and accessible unlike bike racing

the handchoking blocks the air and may prevent exploding the engine at the end of the long straight by richining the mixture adding essential gas and oil (two stroke)

[LooseEqualsFast]

That something i never got while watching karts on TV, i raced club and national level bikes from 125cc to 1000cc i even help testing with the 500cc modenas GP bike of Kenny Roberts snr and not once did mechanic say to me block the air in take, we change maps on the 1000cc superbikes(injection) and added restrictor or differant reed valves jets needles to intake mainifold/carb, are these motors under tuned or something as that would wreck highly tuned 2/4 stroke running it lean like that unless the top and bottom are not set at optium tune, we rebuild the motors ever 700/1000 miles on the 2 strokes.Back in the days of no motor limits you set them so lean for max power that they would siezed or blow as they cross the finish line,  i only tryed the kiddy karts you get given at places like chedder gorge so im nieve to the engine tune these karts have. i understand why it done but not why it needed to be done.

Some differences between the motorcycle motors and the older karting models that might help explain.

Karts are most single gear therefore they have to operate efficiently over wide RPM range (9000-21000+)
To compensate for this they need a lot of overrev where the motor keeps pulling beyond peak power. Usually peak power is 13,500 at the latest however they will still pull all the way to 21K and beyond. Needless to say this puts the motors under extreme stress. Especially the 100cc Aircooleds making 36HP
21K RPM + shut throttle = bad. Choking can help with this
Also, fixed analogic ignition mean that the ignition is a compromise sometimes you may encounter detonation at lower RPMs, choking before the turn can help minimize this effect.

[Intrepid_69]

I think it's a must although cant complain. Best karting simulator ever! It's helPed me a lot with my racing here in New Zealand. +1 for me too haha

[Dan Buck]

+1 +1 +1 +1 pleasee!!

[EVO]

Mr. Buck if you get 4  +1s  than i get 100  +1s.    only fair lol  just kidding

[Nathan Dunnett]

+1

As said, choking under braking when running lean mixtures is done for 2 reasons: to get extra lubrication to prevent seizure, and to control temps by temporarily richening the mixture when power output doesn't matter so much.

[Tr!st@n]

I know this topic is very old, but i don't want to start a new one, so i'd like to bump this. +1