More Speed

[jayden727]

Bare wth me guys im completely new to this. I have an 8hp Briggs and Im just wondering what I can do to it to make it faster. Its on a yerfdog two seater and my weight is 180lbs but it only hits about 24mph. Is this right?

 

[02mx-5]

Remove the governor. COMPLETELY. Take the side cover off and remove the wheel with the weights on it. Then just hook up the throttle cable to a new position. If you do this, get stronger parts in the engine like a billet rod. You cna also just put a better airfilter and exhaust on it. Bigger carb kit? You could regear it for more top speed but then you wouldnt have acceleration. The options are endless

 

[jayden727]

Thanks for the reply. My father in law works on engines a little bit so he can help me do things. Hes already took the governor off and that how I got 24mph. It was only doing 18mph.

 

[1992suburban]

how is it geared?
cent. clutch or Tq. convertor??
How tall is your tire??
how fresh is the motor?

 

[jayden727]

I have a 60 tooth in the back and a 10 tooth in front. Motor was bought used but runs good, starts first shot!

 

[1992suburban]

size tire?

 

[jayden727]

Tire size is 20" on back and 15" in front. Its got a centrifugal clutch. Sorry Im new to this.

 

[1992suburban]

Thats NOT enough gear IMO

6:1 ratio with 20" tires unless you got an awesome motor!!!!

Run a jackshaft so you can adjust ratiio accordingly

 

[jayden727]

Does anyone have pics of a setup with a jackshaft so I can see? Im going to put 15" tires on back today to see what speed it gets!
Should I just change sprocket size?

 

[hd4ou]

http://www.yerfrockethellhound.com/new_jackshaft_setup.jpg

one of many but this will give you an idea. good luck, Jody

 

[jayden727]

Thought I had 15" ltires laying around but I dont. Sucks! What sprocket size should I use in back and which one in front?

 

[lemegacool]

changing from 20" to 15" will actually make you LOSE top speed...

do you have good acceleration???

 

[modelengineer]

20" to 15" will actually make you LOSE top speed

Not always. If it doesn't have enough power to reach the theoretical top speed you can get a higher top speed with lower gearing

Like if you run a 1:1 ratio, top speed (according the calculator) will be over 200 mph. However, it's unlikely to be able to move at all. You would get a higher top speed with a lower gear ratio. I know this is an extreme case, but it's just to illustrate the point.

 

[lemegacool]

Not always. If it doesn't have enough power to reach the theoretical top speed you can get a higher top speed with lower gearing

Like if you run a 1:1 ratio, top speed (according the calculator) will be over 200 mph. However, it's unlikely to be able to move at all. You would get a higher top speed with a lower gear ratio. I know this is an extreme case, but it's just to illustrate the point.

yeah ok i get what you are saying... thats kind of why i asked him if he have good accel!

 

[jayden727]

Well I guess we dont have to worry about that anymore. My kart got on fire!! My frame is still good though! lol
What kind of motor should I look for now?? I want to do about 35mph with good acceleration. Is it possible??

 

[1992suburban]

caught FIRE?

details....

 

[NJOHC]

If I was you I'd keep a fire extinguisher on that thing just to make myself feel better from now on! lol If you want top speed, depending on how much you want to spend on an engine, check out GY6 engines. They rev high like a quad but are made for karts. And there are endless aftermarket parts to make them faster.

 

[jayden727]

Yeah it caught fire, still dont know how. Oh well now i'll just get a better engine. Cheap hopefully!!