Rebuilding a YerfDog 3020 with ATV tires

[big-d]

I picked up this YerfDog 3020 for free! I picked up some cheap ATV tires and wheels. The kart had been broken at the front axle several times and booger welded back together each time. The steering shaft was bent in half and the front end (still broken into pieces) had tiny hand truck wheels from harbour freight on it. The rear rims were both bent and rusted to the axle. The kart had been sitting this way for about 10 years.

This is what it looked like the day after I brought it home.

 

[Poboy kartman]

Can you swing by...I'm having trouble with my flashlight.

 

[big-d]

I started bracing up the frame, adding a new front floor, replaced the steering shaft, rebuilt the carb, replaced the brakes, all new bearings and ordered a set of metric pattern rear hubs. I was not able to track down a set of front hubs in the 4x110mm pattern with 5/8 ID bearings. So I picked up a set of ATV hubs and drilled out the inside of them to fit a standard set of bearings. The side bars were angled out at about a 45 degree angle, making it so the larger tires had almost no turning radius. I cut them off and welded them back on so they were straight up. This gave a lot more room for turning the 19 inch front tires.

 

[2SlickNick]

Nice score!
The kart looks great with those wheels... Keep up the progress.

 

[big-d]

Hey Poboy, I thought you couldn't visit threads with large pictures or your phone line would start smoking?

 

[Poboy kartman]

Yeah...my phone doesn't have a line...but it changes from a Smartphone to a slow stupid one....

 

[chancer]

These pics are not that big.

 

[Poboy kartman]

I don't complain until they load very slowly

 

[big-d]

This go kart gets beat like Poboy coming home late for curfew! I currently have it apart to do some more bracing, adding a small trailer hitch (air hose quick connect fitting for a bicycle trailer we built a couple years ago), replace the worn out front spindle attachments and whatever else we come up with.

I am looking for some advise on where to add some tubes and gussets to strengthen up this frame. Or do I just stitch in some tin work around the sides and call it good? It will eventually get a bigger engine too...

 

[chancer]

If its going to continue to "fly" I would gusset everywhere that is obvious.

---------- Post added at 10:55 PM ---------- Previous post was at 10:49 PM ----------

Looks like you built a very nice stout Front beam though

That is what usually breaks on landing! Seeing that, Id say you know what needs gussets

 

[big-d]

Oh yeah, I raised the steering wheel up about 4-5 inches. It was really low in the original setup, like right in your lap. I still need to fix the steering as well. I extended the arms on the spindle with a piece of 3/16" flat strap just to create more leverage so the kids could turn the large tires. Now that I know it works, I need to rebuild them and add some Ackerman.

 

[chancer]

You don't add "some" Ackerman, You either have it or you dont.

Pretty easy though. Just follow an imaginary line from the steering arm angle to the center of rear axle. The bolt hole for the tie rod should centered on the line. I use a string, you can use a long rod too!

 

[big-d]

What is typically used for the sleeves that the spindles pivot from? Just an appropriate sized tube to be able to add a grease fitting without much slop, or does anyone run bronze bushings or?

 

[chancer]

They are typically steel on steel. I made a couple different ones with bearings and bushings.
But they were a different style than your set up.
http://www.diygokarts.com/vb/showthread.php?t=28597

Also made some that used 3/4" gas pipe and a bronze bushing and only had a 1/2" bolt.

 

[big-d]

I have not updated the steering or spindles yet (really stiff steering). I am toying around with the idea of a powerland 420, adding suspension and repurposing this engine to a mini bike or 4 wheeler.

We did paint it. (Not the seat frame yet though) the wheels got an aluminum metallic paint and the body got charcoal metallic. I also threw a couple coats of glow in the dark on all the tubes and rims to surprise the kids!

 

[big-d]

Another pic

 

[SoBored]

Nice work, that Yerf Dog is lucky you found it!