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View Full Version : building a go-kart in metal shop...need a motor



Stevie-D
10-30-2004, 08:01 AM
i've got a small go-kart frame. i'm goint to extend the frame about 2 feet so i can get into it, widen the front end, i have a friend who has an old trailboss that hasnt run in a while. engine is shot. i'm planning to buying the quad off of him for really cheap, then putting the front end (a-arms, shocks, wheels and tires. )on it. then put some mud tires on the back. i'm going to do this all in metal shop at school. the rear end is a limited slip, chain drive. i weigh 180# , so a little briggs & stratton motor just isn't going to cut it. so i'm looking for perhaps a motor out of a blaster, 125 dirtbike motor, maybe a 300ex motor. something big with some balls that will haul my arse around pretty quickly. once i get a motor i will fab some mounts and reinforce the frame so it doesn't twist itself apart.
question: what motor would ya'll recommend? i'm leaning towards a 4-stroke motor, and it must be a chain drive.

TheFontMaster
10-30-2004, 09:08 AM
660r raptor motor :macho

But seriously a 300ex motor should do fine, good power and reliable. And electric start so that you don't have to worry about building the frame to alow you to kick start the motor.

Str8Wicked 74
10-30-2004, 09:11 AM
check ebay for a nice used 80cc two stroke bike motor. hell, even a 125 if you got the loot

theTman
10-30-2004, 09:28 AM
300ex...maybe even a 250ex

redrider69
10-30-2004, 10:18 AM
250ex is shaft drive so its out i wold prolly go with the 300 or a cr/yz 80 motor if u dont mind it being 2 stroke but then again its kick start so go with the 300

theTman
10-30-2004, 10:27 AM
Originally posted by redrider69
250ex is shaft drive so its out i wold prolly go with the 300 or a cr/yz 80 motor if u dont mind it being 2 stroke but then again its kick start so go with the 300


yea i forgot about the shaft:o

fastkid400
10-30-2004, 11:29 AM
how do u plan on riggin up the shifter with a dirt bike or quad motor? if i was u, i might look into either a snomobile motor(that would be awesome), or some automatic transmission quad. u can get hole old snomobiles for pretty cheap, less then a 300ex motor. then just have a belt pulley on the axle, just a suggestion.

NTPRacing#19
10-30-2004, 12:55 PM
im building a go cart and im putting my yfz450 motor in it for the off season. thing should go like a raped ape. my friend has a 400ex motor in his. they are gonna be fast

Pvt. Maggot
10-30-2004, 01:33 PM
i have a kx80 motor ;)

YFZ450Ridr
10-30-2004, 02:17 PM
my uncle is makin one out of his old warrior and he has a turbo charger off of a little suburu wrx sittin there waitin for it.

sam the brave
10-30-2004, 02:26 PM
put the biggest engine u can afford in it
like a r6 or cbrr600 so it will be fast

Stevie-D
10-30-2004, 03:25 PM
i have a kx80 motor

how much $$$?

YFZ450Ridr
10-30-2004, 03:36 PM
like a raptor 660 motor wouldnt be to bad i dont think. its got plenty of power and it would be pretty dam fast too.

speedfreaksguy
10-30-2004, 03:51 PM
I have a 72 Kawasaki GT750 motor. 3 cylinder liquid cooled 2 stroke. Now that would haul *** on a go cart. Better buy some good health insurance.

Stevie-D
10-30-2004, 05:17 PM
i don't have enough insurance for a rappy motor, or enough cash. so i'm leaning towards the 300ex motor.
someone asked before how i plan on shifting it. here's my plan:

I'm going to remove the shifter, then put a piece of band iron on the shaft, which will be about 3 inches tall. i may need to extend it out to clear the engine case. from there, i am going to run a piece of solid steel tubing (bout 3/8" thick) from the new shift lever to about a foot in front of the seat. it will attach half way up a lever that i will mount to the frame. so when i pull back, it shifts up. push forward, it shifts down. get what i'm trying to say?:huh :p

for the clutch i am going to simply add a third pedal up front that i can run the cable to.
it has a drum brake on the back. i can lock up the back right wheel with one foot, and get on the gas with the other. oughta make one hell of a burnout, which is why i want a larger motor for it instead of say an 80cc 2 stroke.

deffinately building a roll cage and adding a seat belt to keep me in it in the event of a rollover. i'm going to make a small rollbar type thing to encase the engine so it wont get screwed if it rolls:)

i have an idea for the front end of it. like i mentioned before, i'm planning on putting the front end off of an old trailboss on it. so a-arms, shocks, and thats about it. i'm going to put some smaller go-cart tires on the front of it, and some big arse tires on the back. something like Razr's, holeshots, etc...
now i'm trying to figure out a way to mount the shocks up front. i'm thinking some round tubing in a horseshoe shape coming off the top of the frame, them some brackets to bolt the top of the shocks to.
this will probably be later on down the road after i get a motor mounted in it and running.

i'm most likely going to get an older 300ex motor. mainly because it is air cooled, (no radiator to mount or protect), very basic to install, (fab up some engine mounts and i'm good to go)and simple to operate and start. plus its a honda and i plan on painting it dark red and black with some white in there a bit too:D

can't wait to start it
:devil:

dunnonuttin
10-30-2004, 06:42 PM
go to the yamaha site and go to usa motor corp and click kart engines

Stevie-D
10-30-2004, 07:29 PM
too expensive:eek2:

exatak199
10-30-2004, 08:22 PM
if you use a 300ex motor then you should look into a big oil cooler if you dont have much air flowing to the engine. it would suck to over heat it:blah:

Stevie-D
10-31-2004, 02:16 PM
if you use a 300ex motor then you should look into a big oil cooler if you dont have much air flowing to the engine. it would suck to over heat it

i had that thought too. i plan on mounting the oil cooler to the right side of the seat so some air will get to it. :macho

Scott-300ex
10-31-2004, 02:52 PM
if you get a clutch you'll have to remember to put it in nuetral before you start it




dude, just get a Ford 302:D

TheFontMaster
10-31-2004, 04:05 PM
Originally posted by Scott-300ex
if you get a clutch you'll have to remember to put it in nuetral before you start it




dude, just get a Ford 302:D

One of my friends in my auto body class was seriously gonna put a ford straight 6 and rear end into a lawn tractor. He decided not to:o

TN94z
10-31-2004, 04:09 PM
I have a 96 Factor One microsprint that has a 96 cr250 motor that runs on alcohol. We used to race them but don not anymore. On a 1/4 mile dirt oval, it would run like 107 mph. I will sale you that "GO KART" for 4000.00 and that will give you a bad motor that will definately haul you around quickly. I also weigh 180 lbs. I will sale the motor for 1300

dunnonuttin
10-31-2004, 06:16 PM
top fuel dragster:blah: :p

400exbiggun
10-31-2004, 06:34 PM
a 80cc would be plenty of power.

I dont really see where you are going to be able to use the power of anybigger of a motor. Any gokart, unless you have a oddesy (sp) or some really good suspension is just going to bounce you to hell. You will never probably hit 6th gear. Unless you are riding on the road, then in turns it might get a little bouncy i would imagine.

Just get a 80. It will haul you around fine, or get a 125.

Hell....y not just get a actual oddesy motor....plenty of power to move ya...and some had reverse as well:blah:

10-31-2004, 06:56 PM
this should help you out

Click Here!!!!!!!!!!!!!!!!!!!!!!! (http://www.exriders.com/vbb/showthread.php?s=&threadid=128921)

wheeltrax
10-31-2004, 08:45 PM
I have the briggs and stratton animal on my kart, it has lots of torque for a small motor, and sounds *****in

LazeR
10-31-2004, 10:44 PM
When you get further into the project you should post up some pics!

chucked
11-01-2004, 08:51 AM
Originally posted by dunnonuttin
top fuel dragster:blah: :p
no, go kart

LTZ400rider
11-01-2004, 10:08 AM
i always wanted to put a harley v twin into a riding mower. a lt500 engine or banshee engine would be sick but probaly expensive and too powerful. id go with a 2 stroke 80 or 125 with a drag pipe:macho

Scott-300ex
11-01-2004, 06:45 PM
Originally posted by sEX
this should help you out

Click Here!!!!!!!!!!!!!!!!!!!!!!! (http://www.exriders.com/vbb/showthread.php?s=&threadid=128921)

i bumped it


for fun........since that guy liked to do it.:p

Toadz400
11-01-2004, 08:22 PM
I'd get a snowmobile engine in there, an older one probably from the 70's or 80's. That way you don't have to deal with making your own shifter, and you can adjust the clutch so you can do burnouts easily.

As for the Trailblazer front end...are you sure you can't find anything else? lol

sportraxkid
11-01-2004, 09:28 PM
If I were u I would look for a hole bike, older 300ex or 250x. the suspension would work alot better do you really want those big ugly *** struts on the front of your cart? plus it would be more like
honda pilot. so u can jump it and go go offroading with sport quad suspension and u could use the axle and swingarm and have disc brakes.

Toadz400
11-02-2004, 11:00 AM
Originally posted by sportraxkid
If I were u I would look for a hole bike, older 300ex or 250x. the suspension would work alot better do you really want those big ugly *** struts on the front of your cart? plus it would be more like
honda pilot. so u can jump it and go go offroading with sport quad suspension and u could use the axle and swingarm and have disc brakes.

Exactly what I was thinking, I wouldn't trust a Polaris front end...or basically anything from an old TB. You could basically make the go-cart a 300ex except don't use the frame. The swingarm would work nicely too with the rear suspension and axle, if you could get it to work out somehow, that way you'd basically have a lowered quad so it'd handle nice.

wilkin250r
11-02-2004, 02:15 PM
What kind of suspension do you have planned for this thing? Your suspension design will probably dictate how much power you can handle. For example, if you have no rear suspension, then even 80cc 2-stroke or 185cc 4-stroke is going to be too big, and you'll bounce yourself to death (unless it is strictly limited to pavement).

I think the MacPherson strut front suspension from the Trailboss is a bad idea. The go-kart will have a MUCH lighter front end than a quad, and the front suspension will be way too stiff, almost as stiff as having no suspension at all. You'd be much better off going with a dual a-arm design, say from a 300EX. At least that way you can either get new shocks that are much softer, or change the angle of the shocks to change the leverage to make them softer.

What are you doing for rear suspension?

Stevie-D
11-05-2004, 08:13 PM
alright, here's my plans as of now:
no rear suspension. i plan on running it on pavement mostly. the rear end is in good shape, i took it apart and looked it all over good. my friend has an older snowmobile engine that i'm considering buying for it. its a 400cc 2-stroke:eek2: i don't need it that big, but what the heck, the price is right:p .
i've reconsidered the front end of it. the older trailbosses (88) didn't have macphereson struts, but regular e-arms and shocks. but still, i'm planning on leaving it how it is for now. my main objective now is to get a motor for it, make some mounts, and stretch the frame out some. once that is done i will consider some front suspension.
as for it being super rough riding, i'm going to put a hinged seat with some springs on the back so i don't feel all the bumps:chinese:

MotoX3
11-05-2004, 08:18 PM
my bro and i built a go cart.....its a lil kids two seater.....we have a 5 hp briggs in it.....trust me you want suspension....it has none and i jumped it off a little kicker i had set up for my motorcycle.....:eek2: wasnt pretty...broke a rim in half...the floor pan dropped out and the side of the frame bent.....good times being 12:chinese: :eek2: :macho

Stevie-D
11-06-2004, 07:05 AM
lmao. i've done some dumbarse stuff like that. i used to have an old bike that i jumped off of a ramp. i landed, and the bike BROKE IN HALF:eek2: right in front of the seat post. it was all rusted and just gave out. gosh that landing hurt:p

anyway, my go-kart is a one-seater. i don't plan on running it off-road much. it will be for the pavement. that is why i want such a big motor- so i can light the friggin tires up on it! ive got a 4x4 truck with some muddin tires on it and the quad, so i'm set for off road. the front end of it will only sit about 3-4 inches off the road. this will be my pavement pounder:devil:

i'm 99% sure i'm going to use my friends 400 2-stroke motor in it. :eek2: i'm having concerns about the strength of the frame being able to handle all that power. so i'm drawing up plans to reinforce the frame so the motor doesn't rip the frame apart.