Need help with kt100j engine

[SRB-J3T]

The problem i have is my kart feels like it dosent have enuff power everytime i power out from a corner. Can someone tell me what i should do to fix this? thanks

 

[anderkart]

Maybe your karts just geared for a super high top speed. (if so, this would cause it to accelerate more slowly)
Count and post the number of teeth on both your engine and axle sprockets. Also include the diamiter or circumference of your rear tires and we'll be able to figure out how your gears are set up now.

If you'd rather figure this out yourself, here's some links to a few calculators:
http://www.gokartracing.org/Calculate.htm
http://www.diygokarts.com/speed-calculator.html

Here's one in case you have a jackshaft setup:
http://www.compgoparts.com/TechnicalResources/JackshaftRatioCalculator.asp

ps:
I'm not sure how many RPM's (stock or modified) KT100's usualy turn but we could research this and probably find out here: http://karting.4cycle.com/forumdisplay.php?f=26 (that site would be a really good place for you to find all kinds of info about your motor)

 

[SRB-J3T]

Maybe your karts just geared for a super high top speed. (if so, this would cause it to accelerate more slowly)
Count and post the number of teeth on both your engine and axle sprockets. Also include the diamiter or circumference of your rear tires and we'll be able to figure out how your gears are set up now.

If you'd rather figure this out yourself, here's some links to a few calculators:
http://www.gokartracing.org/Calculate.htm
http://www.diygokarts.com/speed-calculator.html

Here's one in case you have a jackshaft setup:
http://www.compgoparts.com/TechnicalResources/JackshaftRatioCalculator.asp

ps:
I'm not sure how many RPM's (stock or modified) KT100's usualy turn but we could research this and probably find out here: http://karting.4cycle.com/forumdisplay.php?f=26 (that site would be a really good place for you to find all kinds of info about your motor)

hey yeah thanks for the help but on the motor u can set lower rpms or higher but even then i put it at a slow but fast take off still u can feel it theres no power

 

[bajagokart]

how the frick can you change your rpms? either you do mods and they increase or you dont do mods and they stay the same

 

[Kenny_McCormic]

Pipe and gearing.

 

[ed1380]

he means gearing. he says that even geared low it still feels slugish.

in that case tune the carb. its either too rich or too lean. isnt it always

 

[anderkart]

hey yeah thanks for the help but on the motor u can set lower rpms or higher but even then i put it at a slow but fast take off still u can feel it theres no power

Did your kart used to have faster take-offs? (or has it always been like this since you owned it)

I was also kinda wondering if your running an old Tillotson carb that might be over due for a set of new diaphragms? (they only cost like $10 and are easy to replace)

 

[SRB-J3T]

@ed1380 yeah thats what i meant it was geared low, even though it is geared low like ed1380 said its still slugish until i hit about maybe 15 ks then it starts to take off properly

 

[anderkart]

Cool, so meyby your gears aren't the problem here. Theres tons of things that can cause poor performance issues. To start, you never really answered either one of my questions in post #7.

 

[Kaptain Krunch]

Does the engine actually sound like its bogging and straining or is it revving up fine and just not moving very well?

 

[Kenny_McCormic]

What do you have for exhaust?

 

[Rickracer]

Those motors make peak power at around 11,000 to 12,000 rpm, with the clutch hooking up in the mid to high 10s,

 

[SRB-J3T]

look when i accelarate it sounds like its bogging and straining, dosent go you can feel theres no power. But then it starts to pick up speed when im doing over 10 kmh and i accelerate i can feel the power quite well sounds perfect aswel. then when i go into a corner and slow it down a little and i want to power out it bogs on me and then i have to wait abit till i gain speed, i honed my cylinder just to get abit more compression also my piston ring and piston is fine.

 

[modelengineer]

Those engines don't make any power at low revs. In a road kart they never really drop below about 20 kph so it stays at higher revs. If you don't like the bogging you need to gear it even lower, or get a different/bigger engine.

 

[Kenny_McCormic]

Why are you coming off corners so slow?

 

[Kaptain Krunch]

Get an expansion chamber if you dont already have, and if it isnt the way you want it then your just going to have to accept that these small 2 smokes have a pretty narrow powerband.

 

[SRB-J3T]

Those engines don't make any power at low revs. In a road kart they never really drop below about 20 kph so it stays at higher revs. If you don't like the bogging you need to gear it even lower, or get a different/bigger engine.

yeah mate i wish it was like that but im on 100j class cant get bigger motor till im in seniors

 

[SRB-J3T]

Why are you coming off corners so slow?

im not coming into the corners slow i fly into the corners but even though wen i exit the corner still need abit more power

 

[modelengineer]

Slow in, fast out...

 

[Kenny_McCormic]

10 km/H is 6-7 mph, that's how fast the average person jogs.