Started my Low Budget Dirt Bike Powered Go Kart

[Sentrek]

Finally started my low budget dirt bike motor powered go kart. So far money spent is $40 for the kart (90% complete), $40 for the dirt bike that the motor came off of + another $40 to get that motor running. Traded an old poor condition mini bike and a edger motor for the axle, hubs, bearings and flanges as well as a set of pedals.

The only things I should have to buy new if I cant manage to find good ones on craigslist is wheels and tires for the front, and new tires for the rear wheels. I already have the chain & sprockets, and the brakes from the same dirtbike the motor came from and a battery for the electric start. I will need to cut the dead axle out and extend the rear of the frame about 6". I will also need to fab a shift lever and mechanism of some sort.

Ive been racking my brain on how to do the clutch. I wanted it to be another foot pedal like a car but since the steering shaft runs right down the middle of your feet I see no practical why of doing it so I think I what I am going to do is hook up a hand lever to my shifter lever.

I had to drill out my wheels to fit the hubs I got today, They are close enough to at least get it mocked up, if they close enough I cant tell I will probably just use them permanetly. And yes, I will be stripping and refinishing those wheels.

My progess will be slower than most since I am saving for a trip next month and I work 6 days a week and dont get home until 7pm every night but I will get it done.

Shot at 2011-10-09

Shot at 2011-10-09

Shot at 2011-10-09

Shot at 2011-10-09

Shot at 2011-10-09

Shot at 2011-10-09

Shot at 2011-10-09

 

[kendelrk]

looks real nice already, whats with the paint on the floor tho?

 

[Sentrek]

Didn't have anything to put down.... Besides...it's a garage

 

[kendelrk]

haha thats my motto, looks good tho, cant wait to see this thing done, what speed do you think youll get out of it?

 

[Sentrek]

I have no idea yet to Be honest....

 

[fowler]

nice job

my only concern is where is the exhaust port
it looks like it is hart up against the seat

and what is that gsxr in the back ground for (if it is one of those)

 

[Sentrek]

The exhaust port is right up against the back of the seat, that is one reason I need to stretch the frame a little bit. And yeah, it is a 2007 GSXR 750 motor. It was for a Go Kart build but i am trying to sell it to help fund my trip next month.

 

[Sentrek]

Well, I got the motor mount cut off tonight. I started to cut off the tube that the jack shaft mount is attached to but realized it was welded on both sides and with the brake band mount welded on there I can not get to half the welds to cut it loose. I decided to cut the frame in half right in front of that tube, I cut 3/4 of the way through with out problems but when I flipped the frame over I could not get cut thru without getting hellacious kickback on the grinder so I quit for the night before I lost my temper.

 

[Doc Sprocket]

Looks like a pretty solid start. What size/type of engine is that?

 

[Sentrek]

It's a Chinese Roketta, 200cc, 14.4hp with a 5 speed tranny, top speed on the dirt bike it was from was a supposed 65mph.

 

[Sentrek]

Well, I got the frame cut in half. Now I need input on how to stretch it. The current frame tubing is 1" od with a fat 3/4" id.

1. I have some scrap frame pieces that are 3/4" od and roughly 14 gauge tubing
or
2. I have some 1 1/4" od tubing with a fat 1 1/16" id which fits loosely over the current frame.
3. Go find some 1" tubing with 3/4" id and use the scrap 3/4"od I have as an inner brace support.

Can you weld galvanized to cold rolled? You can right? I have some thin galvanized flashing material I am thinking of cutting some strips to tack to the frame and use the 1 1/4" tubing over top of them to get a good tight fit and then do a nice bead all the way around the end of the tubing to close the gap. That should be good and strong right?

let me know your thoughts.

Shot at 2011-10-11

 

[fowler]

reverse that list and try each idea in decending order


u can weld galv to bare steel but it is advised to grind the galv off as burning galv is toxic and gives a poor weld

 

[Sentrek]

Well, I went with option #3, I thought it would be strong enough and look the best when said & done. I thought I had taken more pictures then I did tonight, I guess I was too focused on getting the frame stretched. Maybe tomorrow I can start fabbing the mount for the axle bearings.

This is the scrap piece of frame I had that I cut for the inner bracing

Mocking up to see how far too stretch the frame. I went with a over total stretch to a 59" wheel base give or take 1/2" if I remember correctly. I did not want the frame to get to excessively long. Now, should I mount the axle on top the frame or below the frame? I am thinking on top myself, either way I go I am more than likely going to need to fab up a chain roller to keep the chain off the lower engine case.

Almost done, I welded the top side, I still need to flip it over and weld the bottom side. When I put the 3/4" od tubing in as a brace I did go ahead and take the paint off and tacked them in place before sliding on the 9 1/2" spacers.

 

[Sentrek]

I managed to get my mounts for the axle made today, I am hoping tomorrow and I can find enough time to get them tacked to the frame and start figuring out my motor mounts.

I also did some trading today and picked up this nice 13 horse honda motor. No gas tank but with a little gas in the carb it starts right up and purrs like a kitten. I also picked up a edger with a strong 4hp craftsman today at a yardsale... for $20!!!

 

[kendelrk]

thats insane, whats this 13 horse going into?

 

[Sentrek]

I'm not sure yet. Maybe that single seater standing up against the wall?

 

[Sentrek]

I got the axle and the muffler mounted up today. I need to check the scrap piles at work for material to start fabbing the motor mounts and the shift linkage. I took measurements from the front spindle mounts to the center of the axle and from the top of the frame tubes to the center of the axle. This was the best way i knew how to keep the axle square to the frame and front wheels.

Dont look at my weld in this picture, I had to grind it down and go over it again, it was pretty bad.

 

[Clayton]

Looking good. That thing will be pretty fast.

 

[Sentrek]

Probably faster than I would ever be willing to ride it.. at least I hope it is.

 

[B.M.800]

Probably faster than I would ever be willing to ride it.. at least I hope it is.

If thats the case, you could gear it lower and have some monster hill climbing ability. I might get some bikes off my uncle sometime, couple of them topped out at 120mph, cut the speed down to 40 or 50 and have boatloads of lowend power... just enough to put my buddys 350 warrior to shame...