Building a new drive train

[maceycd]

I just got my first mini bike
http://www.oldminibikes.com/forum/what/28455-my-first-mini-bike.html

Now I want to get it running. I am looking at the HF engine
- Harbor Freight Tools - Quality Tools at the Lowest Prices

If I get that do I also need a clutch kit? Where do I get one? Brakes would probably be a good idea. Should I go with an EBAY kit like
MINIBIKE Mini Chopper GO KART Brake Kit w/72T sprocket - eBay (item 220579264135 end time Apr-25-10 12:29:28 PDT)

Then I need to connect to my rear wheel would any chain work like
Yamaha drive chain 1976 Chappy mini bike : eBay Motors (item 180490046344 end time Apr-11-10 15:19:19 PDT)
or do I have to get someone to make me a correct length chain?

Thanks for any help.

 

[viper7016]

I do a lot of my shopping on these two sites. They are specifically for mini bikes and go karts.

Snowmobile Parts, ATV Parts, Go Kart Parts, Mini Bike Part, Lawn Mower Parts, Chainsaw Part and Small Engine Parts

BMI Karts and Supplies - Home


I have that HF engine, its nice. This is my 2nd one and I bought another for my uncle's bike.

This is an Excellent clutch for the money, Max Torque - Max-Torque Chain Drive Centrifugal Clutches & Parts
You will have to match it to the size chain and sprocket you are going to use. Most small mini bikes use #35. The HF engine has a 3/4 shaft.

As for chain, you can try and find a place around you that sells it by the foot. I know I got some #35 at Tractor Supply for $16 for 10feet. Or something like - 11-384 - C-35 Chain 10 Foot Roll

MFGsupply has brake systems that work with their sprockets if you want to check them out, the biggest thing is spacing. On my bike, I don't have enough room to run a hub brake on the back wheel and still keep my wheel centered on the frame. So I run a clutch brake. 4-486 - Brake Band w/Pin (For Our 4-485)
This band uses my clutch for a drum to brake.

Have fun : D

 

[maceycd]

Thanks I will count my teeth on the rear wheel tonight. With a centrifugal clutch do I need a clutch cable or does it engage automatically?

 

[viper7016]

#35 chain is just the size of the links. #25 has smaller links and #41 links are larger. It doesn't matter how many teeth are on the sprocket.

The clutch will engage by it self when your motor gets up to 2200 RPM.

 

[maceycd]

Cool I just got a clutch, brake band, brake drum brake cable, and chain. I cannot wait for it to get here.

 

[joekd]

Hope you took the advice and picked up a max torque clutch, use them on the kart and I have nothing but good things to say about them

Also kep in mind you may need a chain break tool to take out links from the chain to fit your bike (most new chains have a ton of extra length to them to be sure you dont run short)

Do you already have a brake lever? Otherwise you need one of those too

 

[viper7016]

The chain tool is probably a good idea. However I do not have one. You can cut/grind the head off one link and pound it out with a nail or something. Reassemble with a master link. :wink:

 

[Shorty]

Here's a good place to get parts! Here on OldMiniBikes.
OldMiniBikes.com - Discount & Replacement Mini Bike Parts

 

[viper7016]

That's a cool bike btw.

 

[joekd]

The chain tool is probably a good idea. However I do not have one. You can cut/grind the head off one link and pound it out with a nail or something. Reassemble with a master link. :wink:

If doing this way put a small (3/8" or so) nut under the backside. Will make it a lot easier to get the link out.

 

[maceycd]

Yes I got that the max torque clutch that viper suggested. I am going to probably do the chain the cheap way. When I measure the chain do I want some slack or make it as tight as possible?

thanks for the comments and help

Also I am going to make my own foot brake. I am thinking about using the pad off of a subaru since I am a big fan of subarus.

 

[viper7016]

Subaru!

Your motor plate should have slots in it. Bolt your motor in halfway up the slot. Put one end of the chain on your back sprocket then around your clutch and back to the rear sprocket. You want to use the teeth on the sprocket to make sure it lines up. Cut the chain to length while it's tight.

When you go to put the chain on the bike to ride it you don't want it tight. So just bump your motor back a little bit to get some slack and as the chain stretches, move it forward.