Speed Of Your Karts

[spudkilla224]

hello i'm building a yard kart, it's powered by a 5.5 HP Honda Clone, It has 10" wheels, a 12 tooth clutch, and a 60 tooth drive sprocket. and i weigh about 120 lbs. so i was wondering how fast my yard kart would go?

and what is the average of your karts top end speed?

[jr dragster Tyler]

Well my kart has 18" wheels 6.5 hp with a header and a torque converter with a 12 tooth sprocket, And a 72 tooth rear sprocket, And I weigh around 120 lbs also and I can get it up to around 64 KMH.

[Kenny_McCormic]

Use the calculator. http://www.diygokarts.com/speed-calculator.html

[JerryAssburger]

With your present gearing, you'll be doing just over 20mph @ 3600 rpm. So your top speed will depend on how hard you're willing to twist that motor. If you can, find a 48t sprocket on ebay, and that'll up your speed to about 28mph @ 3600 rpm. Your acceleration won't suffer too much, and you'll definitely feel the difference on the top end. A stock 6.5hp clone geared correctly will get you to 45mph, so your 5.5 should do pretty well too. Depending on your rear rims, you can also mount a pair of taller profile tires to up yopur top speed.
Like it's mentioned in a few places on this forum, 30mph is nothing to sneeze at, 4" off the ground!

[jarcynvicnchris93]

hello i'm building a yard kart, it's powered by a 5.5 HP Honda Clone, It has 10" wheels, a 12 tooth clutch, and a 60 tooth drive sprocket. and i weigh about 120 lbs. so i was wondering how fast my yard kart would go?

and what is the average of your karts top end speed?

I think the info Kenny and Jerry gave you is outstanding for predicting speed. But when you get your kart built see if you can use a GPS to record your speed. Most Garmins allow you to reset the highest speed reached. That way you can keep the GPS in your pocket for safety reasons. Cuz looking at it and driving at the same time can get you in trouble fast. Wiping out at 70 on the water with a jetski is one thing (been there done that-scars to prove it) , wrecking on a kart is totally another all together. Good luck on your Kart. Post some pics as you go. These guys are awesome with the advice, inspiration, and encouragement.

[JerryAssburger]

I think the info Kenny and Jerry gave you is outstanding for predicting speed. But when you get your kart built see if you can use a GPS to record your speed. Most Garmins allow you to reset the highest speed reached. That way you can keep the GPS in your pocket for safety reasons. Cuz looking at it and driving at the same time can get you in trouble fast. Wiping out at 70 on the water with a jetski is one thing (been there done that-scars to prove it) , wrecking on a kart is totally another all together. Good luck on your Kart. Post some pics as you go. These guys are awesome with the advice, inspiration, and encouragement.

.... you're right! I've done the GPS and driving thing on just about all of the karts/trikes, and it's a handful (pardon the pun)
Spudkilla224's 10" wheels kinda limit things without going nuts on gearing. The 48t is about the smallest #35 rear sprocket readily available, that's why I was thinking he might want to look into the taller profile tires.
I guess with all predictions, "Your results may vary" should always be in there somewhere.

[scar]

nourthern has a 45 tooth sprocket for 15 bucks

[ZnsaneRyder]

196cc Honda Clone, direct flow to the air filter (no restrictive airbox cover) and no governor.

Hilliard Extreme Duty clutch, with 1800RPM springs

3:1 axle ratio (belt drive) and 10" Marathon Flat-Free solid poly tires. Gives me a good 50MPH. Max I've ever clocked, ducking my head close to the handlebars to reduce wind resistance with tight clothing on (according to bike speedometer) is 51.6MPH.

[trails]

nice!pix plz. pm or post a thread

[ZnsaneRyder]

nice!pix plz. pm or post a thread

I'll post more pics, but every time I try to upload, the :censored: upload window stops responding and turns blank white, and it won't upload. :useless:

There's a new thread in the minibikes section.

[trails]

k. thnx

[Russ2251]

I'll post more pics, but every time I try to upload, the :censored: upload window stops responding and turns blank white, and it won't upload.Means pics are too large.

[modelengineer]

My kart should do 70-75mph because it's geared for acceleration. Could probably hit 100mph with the right gearing but top speed isn't where it's at, acceleration and cornering is the fun part for me.

[ZnsaneRyder]

My kart should do 70-75mph because it's geared for acceleration. Could probably hit 100mph with the right gearing but top speed isn't where it's at, acceleration and cornering is the fun part for me.

70 would be scary on a go kart.

AND WAY TOO MUCH FUN!

[trails]

ZnsaneRyder- go look at modelengineers kart in the photo log. its amazing. not your average kart. not your average engine

[modelengineer]

Thank you very much trails!

[trails]

no problem, by the way. im zach. ive been watching your build. do you have an estimated completion date? i cant wait to see a vid of this baby runnin.

[modelengineer]

I hope to be finished sometime mid-late january or at the latest early feb.

First time I take it out I will be sure to take a video!

[trails]

ill be sure to watch the vid man. where did you get the idea to build that much of a cart. thats a offroad monster

[Sam.s.94]

how do you measure speed of a kart ????

[Russ2251]

Speed calculator can be used to ballpark speed.
http://www.diygokarts.com/speed-calculator.html
Using a TinyTach also works.
http://www.tinytach.com/tinytach/commercial.php
Or a GPS can be used.

[jr dragster Tyler]

Russ do you think the TinyTach that updates every 2 seconds would be alright for my kart? I wasnt sure because there's a fine line where overrevving is and it wont take long to get there.

[Russ2251]

Get the more expensive one. Updates every 1/2 second.
2 seconds is a long time when monitoring rpm, especially when dealing with anything modified.
The extra $30 is well worth it. My opinion.
I was considering buying a 2nd unit, but I may just wire up both engines and monitor each through independent switching.

[jr dragster Tyler]

Ok thank's Russ. That's what I was thinking that in 2 seconds it could go from safe to not safe and not realize it.

[Kenny_McCormic]

A $10 digital bike speedo makes a GREAT 10K rpm tach.

[ZnsaneRyder]

A $10 digital bike speedo makes a GREAT 10K rpm tach.

Plz explain how this is done

[Kenny_McCormic]

http://www.instructables.com/id/Tachometer-made-from-a-bicycle-speedometer-cycloc/

[ZnsaneRyder]

http://www.instructables.com/id/Tachometer-made-from-a-bicycle-speedometer-cycloc/

THANKS!!! I wonder though, if the magnet going by so fast would affect the accuracy of the magnetic hall-sensor to pick up the RPM.

I also wonder if that magnet would cause a balance problem at high RPM, or even fly off!

What if we used the yellow ignition wire for the kill switch to also get the RPM signal from, and used a transistor to trigger the bike computer instead of the hall-sensor?

[Kenny_McCormic]

Use that big magnet already conveniently located on the flywheel. Gut the big box for the sensor and it will probably fit inside the shroud away from the coil without any cutting. Electricity and magnetism is faster than any engine, I wouldn't worry too much.

[trails]

i want to install one just as a speedometer.

[BradenM]

Measure in MM the distance it takes for one of your wheels to make a full revolution, and key that number into a cyclometer. Then attach the magnet to the wheel you measured (going to have to be some ghetto homebuild here, sorry), and attach the sensor so it is no further then 1/2 inch away, although preferably within 1-2mm. Attach the bike computer to your preference, and make sure you secure the wire from the sensor to the screen.
Braden.

[tallboy2828]

196cc Honda Clone, direct flow to the air filter (no restrictive airbox cover) and no governor.

Hilliard Extreme Duty clutch, with 1800RPM springs

3:1 axle ratio (belt drive) and 10" Marathon Flat-Free solid poly tires. Gives me a good 50MPH. Max I've ever clocked, ducking my head close to the handlebars to reduce wind resistance with tight clothing on (according to bike speedometer) is 51.6MPH.
__________________
Dual Suspension Mountain Bicycle with a big engine on a trailer! 196cc OHV Blue Honda Clone, 100MPG, 50MPH, No RPM limiter 5000+RPM

you mean 18 pound springs, stock springs will do 3600 rpm. ;)