Simple predator 420cc kart build advice?

[ivanivz]

So i just got a steal of a deal on a pretty descent kart and have some questions. I never had a kart and dont know much about them so any info would be useful. What i want to do is put a predator 420cc engine from harborfreight on there. This is a budget build and i just want a simple build yet reliable. Something like the commercial karts they have only with a 420cc engine
http://gokartsusa.com/Commercial-Gokart-for-Rental-Track.aspx

Questions; what clutch or tourque converter do i need (somewhat cheap but still descent quality)
what sprocket ratios and chain do i need?
any other info for those who have a similar setup?

I jsut want to do a simple bolt on and leave the engine fully bone stock as this is a mess around kart that ill be riding around the streets, some drifting here and there and that's about it.

 

[gsegovia]

For a go kart of that size I think an engine that size Is to big, as far as torque converter or clutch, will probably do, most people that run torque converters usually have big tires mostly for climbing hills and stuff like that.

 

[ivanivz]

For a go kart of that size I think an engine that size Is to big, as far as torque converter or clutch, will probably do, most people that run torque converters usually have big tires mostly for climbing hills and stuff like that.

I just want descent power without modding the engine (keeping it stock) which is why im going for the 420, i can get it to mount etc just neeed some technical and drivetrain advice

 

[gsegovia]

How big of Tires are you going with , is it going to be a live axle or not.

 

[ivanivz]

How big of Tires are you going with , is it going to be a live axle or not.

its a live axle and i have no idea about tire size, im thinking of the same ones that are on the kart that i posted the link of or a little bit wider,

 

[Doc Sprocket]

If you want to keep the budget in check, do yourself a favour- get a small block, not a big block. A 6.5hp 200-212 cc engine with very mild performance upgrades will serve well and end up costing a lot less. Part of the reason for this is that the 420 has a 1" PTO shaft, whereas the small engines have a 3/4" shaft. Any clutch or CVT is going to cost more in 1" than 3/4". Then, there's the purchase price of the engine, too.

 

[ivanivz]

If you want to keep the budget in check, do yourself a favour- get a small block, not a big block. A 6.5hp 200-212 cc engine with very mild performance upgrades will serve well and end up costing a lot less. Part of the reason for this is that the 420 has a 1" PTO shaft, whereas the small engines have a 3/4" shaft. Any clutch or CVT is going to cost more in 1" than 3/4". Then, there's the purchase price of the engine, too.

I have money for a descent t/c and the engine, what i mean by budget build is that i dont want to pour out money into modding the engine, basically have a simple yet powerful build, nothing special at the same time i want some power. The 212cc preadator is just to small for me, here is what im thinking for the t/c
http://gokartsusa.com/TC40-Comet-40-Series-Replacement-Driver.aspx
Ill be doing alot of stop and go as ill be riding mostly on streets and not really on any tracks, mostly just for fun, and im thinking this should work good with what i want, any advice such as what wheel size, or any other techincal info?

 

[Doc Sprocket]

Understood. Tough call though, not everyday you see a big block and 40 on a concession kart.

With the available torque, I would suggest you select your wheels and tires based on your needs (or wants) and we'll figure out gearing and other details from there.

 

[ivanivz]

Understood. Tough call though, not everyday you see a big block and 40 on a concession kart.

With the available torque, I would suggest you select your wheels and tires based on your needs (or wants) and we'll figure out gearing and other details from there.

I will be using this on streets only and my kart is pretty low to the ground, here is a vid of a kart that has the 420cc predator engine, so basically something very similiar to that kart wheelbase and structure wise. Also ill be doing a little bit of drifting around corners etc,
http://www.youtube.com/watch?v=JBxine6abvQ&feature=related

 

[gsegovia]

I don't know if you'll have room for a torque converter on a kart that size. I do know they sale clutch that will handle so good power.they cost as much as a cvt but they are built for racing.

 

[ivanivz]

I don't know if you'll have room for a torque converter on a kart that size. I do know they sale clutch that will handle so good power.they cost as much as a cvt but they are built for racing.

ok so my frame isnt exactly a race frame, ill get some pics up later today but its a homemade frame with more than enough room for the 420 to fit in the rear,

 

[Doc Sprocket]

I really think if you're going to be more of a pavement-pounder, you should keep the tire size down, and buy a good-quality centrifugal clutch.

 

[gsegovia]

ok so my frame isnt exactly a race frame, ill get some pics up later today but its a homemade frame with more than enough room for the 420 to fit in the rear,

Am sure the engine will fit, I meant the torque converter, jack shaft, etc...
Check this clutch out,by no means am saying it will work on your engine but its rated for 18hp.
http://www.ebay.com/itm/Star-Racing...pt=Race_Car_Parts&hash=item20c93eaff5&vxp=mtr

 

[gsegovia]

Sorry your engine is a 13hp you can actually find something a bit cheaper,.

 

[gsegovia]

Pictures will help get more members to jump in

 

[ivanivz]

Here are a few pics, i just got it yesterday so i didnt do anything to it yet, planning to repaint the frame, maybe cut of the rear bumpers, most likely ill have to weld on a larger platform for the engine, get a descent seat, new axle bearings, maybe a better sprocket mounting hub, wider wheels and tires (dont know what size though) and install some good disc brakes. This is a 1'' axle, im wondering will it be okay for 13hp? and if i go centrifugal clutch vs t/c whats the difference/ how will it affect tourque/speed, durability, etc.

 

[Doc Sprocket]

The 1" axle will be fine. A decent clutch will tolerate the abuse. I urge you to research the differences between clutches and CVT's. There's plenty of info here, including a sticky on the topic.

 

[ivanivz]

any links of a good clutch for my use? im thinking
http://gokartsusa.com/centrifugalclutchcometazusa-1-1-1-1-1.aspx

 

[Doc Sprocket]

That clutch looks like it would be appropriate, but I'm not familiar with it. Not knowing any better, I'd suggest a race clutch like a Noram. Stick around a bit, there's a couple guys not on at the moment that really know their clutches.

 

[ivanivz]

what do you recommend for wheel size and tire size, front and back?