Hello All-Advice needed.

[gjones5252]

I am working on a go-kart with my kiddos. I have tried multiple routes to gather advice at a few other forums and have been less than successful. This forum seem to be a little livelier and more helpful!
I have a car gifted to me that I am taking apart and rebuilding. It had no engine and someone went to town with an angle grinder.
I am currently removing some rusted panels/pipes.
I am looking at putting in a Predator 420 cc with 40 series torque converter and reverse forward gearbox. The gearbox company will add on a torque converter for $100 but i am pretty sure its knock off stuff. Not sure the reliability. A comet one from Gopowersports is 250 ish. I would like some recommendations anyone has one.
Also, I am looking at what gears to get the gearbox has a 12 w/ 530 chain or 10 w/ 420 chain sprocket that would be my output. seems like i want to be at 6 or 5:1 ratio. Any recommendations on which sprocket to buy.
I also have an axel but the threads are worn down on one side. If this is not fixable I would need a new axle and recommendations for that.
I also need any recommendations for the brakes. I haven't even begun to learn about that.
Thanks in advance and hopefully the pictures help explain what I am rambling about.

 

[Denny]

420 on the chain. Sprockets and chain will be easier to find and cheaper to buy. I think you’re going to need a new axle. The knockoff CVTs have been good to us here. No problems, but the cheap belts suck!!! Buy Only Genuine Comet Belts!!!

 

[Master Hack]

I would give rethreading that axle a try.

 

[bob58o]

How important is reverse? Without the gearbox, that’s one less thing.

Need to know what diameter TIRES to be used on the rear to give sprocket advice.

They sell kits for brakes. Expensive option for a 1.25” live axle in the photo. Chinesium options available on the interwebs. Can you save the rotor and hub? Then you only need the caliper and master cylinder and can spend less.

 

[corylee03]

Looks like you already have a master cylinder and lines if im not mistaken. Brakes should be a matter of getting a caliper and mounting it onto the rear disc. Looks like It will take a little fab work for a bracket.

Im interested in to see this set up completed. I had considered a similar set up for one of our projects but am going a different route at the moment. Engine was still intact on ours.

Bob makes a good point about the tire size for sure. Like Denny said, the 420 chain items will be easier to source and cheaper and more than enough to hold a 420cc.

Good luck and def post updates!

 

[gjones5252]

I would give rethreading that axle a try.

Any tips on how to do this? I am not sure how to make sure that I start out rethreading the outside to ensure I end up aligned with interal threads if that makes sense.

I might try the cheaper knockoff for the torque converter then but Yes i will not skip out on the better belt.

I have no idea what size tires to go with. The ones in the back are the ones that were given to me but I am not sure what the original tire size was and not sure where to even start with that. I was waiting till i solved my axel problem. current tires are 20x10-9 and 19x7-8

I do have the master cylinder but the oil glass viewing screen is broken and I am not sure if it is even functional. I still have the calipers and all but not sure how or what to test with them.
The rotor is salvageable as it's bolted on but the hub is welded to the axle. As it stands I am going to have to flip the axle for the motor to be able to line up and not be pushed way out to the side.

I would like reverse its goofy but I really do not want to keep having to get out and push my kids back from stuff. Maybe that's goofy but yeah.

I am using this as a good project to familiarize my self better with working on vehicles so if I am not making any sense let me know. I am still learning.

This photo is today where we are at with stripping down the rusted garbage on the bottom.

 

[panchothedog]

18 and 20 inch tall tires are what you want. Those are probably the original tires. The cheap torque converters work fine. They're really all quite the same. Quality belts last 5 to 10 times as long as a cheap one. 10 tooth X 60 tooth is the best overall gear ratio for karts with large tires ( like yours ). If the kids are big enough to drive
a 420cc powered kart, they should be big enough to push it backwards. Last comment is personal belief, you do what you want. For me, simpler is better.

 

[Master Hack]

Any tips on how to do this? I am not sure how to make sure that I start out rethreading the outside to ensure I end up aligned with interal threads if that makes sense.

Ya need a threading die of the proper size. That means diameter and thread pitch.
the die will pick up the original threads, if ya just start it straight and don't force it.
Ya may have a coupla boogered threads at the end, but so what? Looks like ya have enough for a nut. Assemble it with blue hot sauce or drill it and pin it, if it makes ya uncomfortable.

 

[gjones5252]

18 and 20 inch tall tires are what you want. Those are probably the original tires. The cheap torque converters work fine. They're really all quite the same. Quality belts last 5 to 10 times as long as a cheap one. 10 tooth X 60 tooth is the best overall gear ratio for karts with large tires ( like yours ). If the kids are big enough to drive
a 420cc powered kart, they should be big enough to push it backwards. Last comment is personal belief, you do what you want. For me, simpler is better.

That’s fair and a good point, it’s hard to argue against simplicity.
Ok sounds good I’ll give the other ones a try and go for a better belt.
Ok awesome I try rethreading it because it’s way worth it to me. Any clue what the thread and pitch is? Or what type of axle so I can start my search? I found some for larger axles but not sure for these.
Thanks for all the help.

 

[Master Hack]

Any clue what the thread and pitch is?

My eye-crometer works purdy well, but not with pics. Is only one side honked up? if so, take it to the hardware store and find the nut that fits the good side and buy a die of the same flavor.

 

[gjones5252]

My eye-crometer works purdy well, but not with pics. Is only one side honked up? if so, take it to the hardware store and find the nut that fits the good side and buy a die of the same flavor.

Hahah I am an idiot. Yeah other side is bueno.
Thank you.

 

[Master Hack]

Hey Denny! I forgot, what kinda belt should i get?

 

[Denny]

For you, I’d get the Rotsa Ruck brand!!!

 

[Master Hack]

For you, I’d get the Rotsa Ruck brand

Thanks, but l can't find those. 去你的美国苏卡 brand is all l can find!

 

[Denny]

Then go with those.

 

[Master Hack]

Then go with those

I sense a slight annoyance here.

 

[Denny]

Not at all old friend!!!

 

[panchothedog]

Don't fall for it Hack. He wants to see you get Yak grease slung all over the place.

 

[Master Hack]

The correct belt has been a vague bit of information. Why don't we just comet and say it? I read the 去你的美国苏卡 brand is made with reinforced yak hair fibers and solidified yak grease. Stronger than carbon fiber and/or that other shyt they put in tires. I think Denny is getting tired of me asking, but I haven't got a straight answer yet. obviously he doesn't get a commission on 去你的美国苏卡 brand belts.
I wonder what 操你个美国混蛋 translates to? SO I looked it up on a translator. I was surprised at the answer! look it up yourself.

 

[Master Hack]

Don't fall for it Hack. He wants to see you get Yak grease slung all over the place.

Thats purdy good advice! I doubt the info he dishes out! the internet on the other hand is always accurate info.