New Guy with New Toys

[speedjunkie]

Hey everyone, I am new to karts and hope to have some fun on these little things. As it is right now I have 2 karts, an offroad cart and a racing cart neither of which have a motor. I was actually hoping someone would be able to tell me what kind of offroad kart I have (we think it is homemade or a knock off of a honda oddessy). I have attached two pictures of the one in question. Also can anyone point me in the direction of a good place to read up on honda clone motors (greyhound 196cc)?

 

[OzFab]

That does look home made, & not very well either. The actual construction looks ok but the engineering leaves a bit to be desired lol.

Every engine recommendation I've seen here has been for the Predator range; that tells me they must be ok

 

[Doc Sprocket]

That's homebrew, allright. Odyssey, no. Not even close. While the pics make it look kind of hack, there are some interesting design elements. The rack and pinion is a good thing, just not sure how stable it is with the angled shaft and u-joints out there in space like that.

The rear suspension is funkadelic! Coilovers aren't too surprising, but the radius arms are! One thing I do NOT like bout that rearend is the fact that the brake rotor is on the jackshaft. If you lose your secondary chain, you lose your brakes. Not the safest design.

Get rid of the seat- too bulky and heavy.

With the size, potential weight, and obvious intended use, I would suggest a big-block engine (11+ HP) and a CVT like the Comet 40. Anything less would offer disappointing performance.

EDIT- Took me a minute to figure out what was bothering me about that axle- got it! Since I can't tell by the pics, I need you to have a close look. Are there any more linkages to that axle other than the long radius arms? Here's the issue- That axle may move up and down as a unit, equally on both sides, and that's just fine. BUT- if the two sides can move up and down at a different rate (articulate), that's going to throw the chain faster than you can say, "it threw the chain again".

Look for a central "hinge" that will allow the axle to go up and down, but constrain all other movement.

 

[OzFab]

EDIT- Took me a minute to figure out what was bothering me about that axle- got it! Since I can't tell by the pics, I need you to have a close look. Are there any more linkages to that axle other than the long radius arms? Here's the issue- That axle may move up and down as a unit, equally on both sides, and that's just fine. BUT- if the two sides can move up and down at a different rate (articulate), that's going to throw the chain faster than you can say, "it threw the chain again".

Look for a central "hinge" that will allow the axle to go up and down, but constrain all other movement.

Hang on a sec; The jackshaft appears to be mounted to the frame (unsprung weight). Unless the axle has a fixed centre & CV ends it would throw the chain regardless of how it's set up, wouldn't it.

The other thing I don't like about this kart is the steering loop/column mounting. Unless that's a 1/8" plate (which would add unnecessary weight), I can't see much strength in it.

@ speedjunkie: Sorry to be ragging on your kart like this; take it as "constructive criticism" (at least you have an idea what needs to be modified)

 

[speedjunkie]

dont worry about critising the cart, i mainly got it for the frame. I am going to redesign the entire thing, and I was planning on finding/using a honda vtwin, probably in the gx 600 family.

 

[Doc Sprocket]

Hang on a sec; The jackshaft appears to be mounted to the frame (unsprung weight). Unless the axle has a fixed centre & CV ends it would throw the chain regardless of how it's set up, wouldn't it.

The other thing I don't like about this kart is the steering loop/column mounting. Unless that's a 1/8" plate (which would add unnecessary weight), I can't see much strength in it.

@ speedjunkie: Sorry to be ragging on your kart like this; take it as "constructive criticism" (at least you have an idea what needs to be modified)

Herein lies the problem. I can't quite see everything. IF the J/S is set up correctly and the axle is constrained from articulating, it could work. I just can't make out those details.

The steering does look unstable. The steering column is constrained at the dash by a bearing assembly, but I do not like the free end in conjunction with the intermediate shaft and U-joints. Looks like it could wobble a lot.

 

[Skittl3]

Im not sure but the rear tire is flat or bent js lol and yah that dosen't look safe at all

 

[Doc Sprocket]

Look at the pic, Fabro- could this be a U-Joint or CV Joint?

 

[Skittl3]

im gonna throw a wild guess for u-joint

 

[speedjunkie]

the rear axle is setup for independent rear suspension so there is a "rear end" (for lack of better wording) and two axles going out the the wheels. Yes those are u-joints you see, yes there is more holding the rear axle in place then just the suspension and the bars connecting to the frame. The steering will be completely redone but I will stick with the rack and pinion set-up. The seat has already been thrown in the trash. I will try to get some more detailed pictures after I get the wheels and tires taken off (I am dealing with a wasps nest in my shop and also some rusty bolts I am treating with pb blaster right now)

 

[speedjunkie]

Ok here are some more detailed pictures of the rear set-up

 

[Doc Sprocket]

Ah HA! So there's hope for it yet! Actually, it's starting to look not too bad for homebrew. I do like to see shadetree engineering.

Now, the downside. You'll definitely want to get rid of that differential. You will find the performance completely disappointing. Replace the entire shaft and diff from u-joint to u-joint with a solid shaft.

 

[OzFab]

Shadetree engineering? Please explain. I'm not familiar with that term.

Hey, I picked it, yay me I thought it had to be, any other axle setup wouldn't have worked.

So, the ideas were there, they just had a bit of trouble executing them. With a few basic mods & a bit of dressing up, this could turn out to be a really nice kart... not that it isn't now...

 

[speedjunkie]

Well this is my first experience building something so I will be asking a lot of questions. I have a 6.5 hp Honda clone that came with this, should I use that or look for a higher horse power motor.

 

[speedjunkie]

Ok, I need some criticism on my idea that I had. What I am thinking of doing is redesigning the rear of my cart to go from an offroad style to more of a solid/rigid design. Anything that is not level with the rest of the frame I will be cutting off. So I will be getting rid of the suspension, radius/trailing arms, independent rear, jackshaft, differential. I will be replacing it all with a solid mounted live axle and box off the rear to mount the engine and have only one chain instead of the jackshaft. Can yall envision what I am talking about? any criticisms or ideas.

 

[OzFab]

Well this is my first experience building something so I will be asking a lot of questions. I have a 6.5 hp Honda clone that came with this, should I use that or look for a higher horse power motor.

That should be ok for this kart, especially once you "lighten it"

Ok, I need some criticism on my idea that I had. What I am thinking of doing is redesigning the rear of my cart to go from an offroad style to more of a solid/rigid design. Anything that is not level with the rest of the frame I will be cutting off. So I will be getting rid of the suspension, radius/trailing arms, independent rear, jackshaft, differential. I will be replacing it all with a solid mounted live axle and box off the rear to mount the engine and have only one chain instead of the jackshaft. Can yall envision what I am talking about? any criticisms or ideas.

That sounds like a great idea. There's a lot of bulk/weight in the back of that thing.

The only thing that worries me (for lack of a better term) is that if the axle is mounted where the existing axles are, you won't have much of a choice but to mount the engine behind it. It's not a major problem but, it's always better to have the engine in front of the axle, it provides better weight distribution

 

[speedjunkie]

So its better to have engine before axle? I was thinking of stretching the passenger area so I could just move the axle back and mount the engine in front of it. It will definitely lighten up the chassis. With lightening it up you think I could get away with dumping the steering rack and just using a steering shaft with one rod going to each spindle?

 

[OzFab]

So its better to have engine before axle?

With the engine within the wheelbase it is supported as the wheels take the weight evenly. With the engine behind the rear axle, the weight is shifted outside the wheelbase, therefore making your front end lighter.

With lightening it up you think I could get away with dumping the steering rack and just using a steering shaft with one rod going to each spindle?

I would keep the rack but redesign the column with a single shaft straight to the rack uni joint. Also, get rid of that loop & replace it with a narrower one with a bush for the column

 

[speedjunkie]

I would keep the rack but redesign the column with a single shaft straight to the rack uni joint. Also, get rid of that loop & replace it with a narrower one with a bush for the column

Was already planing on cutting out that loop and narrowing it down a little, I need to add a bar on my floor going from either side so I have something to weld it to other then the floor board (which needs to be replaced). Having a single straight shaft going to the rack will be hard unless I can angle the shaft at all, or does it need to be straight?

 

[OzFab]

The shaft (steering column) can be anywhere you want it to be if you leave a uni on the rack