Looking for gears

[BluesBuggy]

I have the manco 150cc, it goes fast but my problem is that there is no power for hills. I live in a hilly area and if I stop on a steep hill the kart wont go. On one hill I had to get out and push it.
It has (I think)16/39. Can anyone tell me where I can find some more gears? I was thinking on changing to a 14.
Do I have to change both gears or would just one work? Also, do I have to change the chain?

As it may seem I dont know junk about this thing. It is going to be a learning curve. Main problem with this one is just not enough umph for the hills, unless I have a running start. Id like it to pull, speed I think it does around 30-35mph.

 

[BluesBuggy]

Forgot to add other specs on it.

But its a 10hp (about) with 18in tires.

 

[OzFab]

Welcome to the forum.

That ratio seems very steep (2.4:1), does the engine have reduction gears built in?

Regardless, replacing the axle sprocket is usually the easiest way to go. Reducing your gear ratio (that is, increasing the ratio) will give you more torque for the hills but will reduce your top speed.

If you post some pics we can get a better idea of what we're dealing with.

 

[anderkart]

Do I have to change both gears or would just one work? Also, do I have to change the chain?

Depending on what tooth-count gears are available that will fit your Manco model, you might get away with just changing one. You'd need a smaller (less teeth) drive sprocket and/or, a larger axle sprocket.

This online store: http://rdswebs.net/reliablegokarts....cc3d99ade6a1c0dcf00161&keyword=Manco+sprocket has quite a few Manco sprockets.
You could contact them and ask for the tooth-count of all the drive and axle sprockets they sell, that will fit your model. They might have good gearing advice for ya, or you could post all the available tooth counts back here on your thread. Then we could help you select a good combination of gears.

Here's a link to our speed calculator: http://www.diygokarts.com/speed-calculator.html
If you know your engines max RPM, you could experiment with different gearing combinations to see how they'd affect your top speed. (less top speed = more acceleration)

As far as re-using your old chain:
With swapping to a smaller drive gear, you'd normally just need to shorten your chain. (unless your karts chain adjuster will take up the slack)
Using a larger axle sprocket usually requires a longer chain.

 

[BluesBuggy]

Ill have to try to get some pics. Yea speed is good but as of now Im not to concerned with speed just need more power.

From what I was reading on some on here that that is way low. Ill need something like in the 40 or 50 range. Not sure about the gear reduction.
I dont know much about these things. It is a ??????Gy6 engine I think. Found some numbers stamped under the (I think) cooling fan shroud.

 

[anderkart]

I think the GY6 has a 3:1 primary reduction between its engine and transmission sections.

 

[OzFab]

I think the GY6 has a 3:1 primary reduction between its engine and transmission sections.

That makes sense, that would take the overall drive ratio to 7.3:1

 

[BluesBuggy]

What would be a good gear for hills? I cant really call these websites to ask them but Im thinking around 54 if I can find such size for my kart.

 

[anderkart]

Yes, changing your axle sprocket from your 39-tooth to around 54 would help your kart climb hills much better. Or replacing your 16-tooth drive sprocket with a 13 would give you similar results. (decreasing your drive sprocket by 3-teeth, is approximately equal to increasing the axle sprocket by 18-teeth)

You could email Reliable Go-Karts instead of calling, you can email them at this link: http://rdswebs.net/reliablegokarts....act_us&zenid=be38d8c947cc3d99ade6a1c0dcf00161

 

[BluesBuggy]

Got ahold of a person at kartsrus but no luck with them, they only have OEM parts.