3203 Build

[Mrmonk7663]

I posted briefly about my 3203 I am building. Here is my project log.

I picked this thing up for $150 and an old air compressor. It was very rough. I started by cutting the floor out and sanding/stripping it. I added steel diamond plate for the new floor. I rust treated and primered the kart, then painted it.

From here, I redid the suspension. New spindles, tie rods and A-arms were added along with some heavy duty shocks from GPS. Stainless hardware was used for most bolts and nuts. I liberated a predator non hemi from a water discharge pump. I acquired (new). The predators are red on the water pumps. I added a custom to my spec stainless steel 1” header to clear the frame with suspension compresses. Topped that off with a RLV muffler. For the carb I used a Japanese superjet with modified circuitry and bigger low and main jetting, along with a modified emulsion tube. Intake is an Arc billet piece with the nuts “sunk” in the adapter to increase flow. Typical clone filter with sleeve.

Tires for the front are 15x6x6 knobby from Argos. Rear wheels are 8x8.5 from BMI with 20x10 kinda scorpion. Rear wheels are 4x4 and I used a hub from BMI.

Gearing is 60x9 with a #40 chain. Finished it off with a GPS 6” torque converter.

Axle is 40” from BMI

Kart starts on first pull and sounds amazing. Throttle and brake still need to be hooked up, and the tie rods need to be attached to the a-arms. I plan on doing that tomorrow. Also a couple more pieces of foam need to be fitted along with the seat reinstalled. Other than that she is ready to rip. It’s been a fun project. From the way the torque converter engages in the jackstands...I can tell this thing is. Going to rip!!! Next up is finishing the Baja and starting the build on the 30032 yerfdog. The Baja has a thread; I’ll make one for the 30032 soon.

Enjoy the pictures!!!

Side note-I’m going to be testing out some steering bushings that can be installed without removing the steering shaft in order to take up the slop these Yerfdog have. I’ll report back with results and information of successful.

 

[landuse]

It is looking sweet!!

 

[Mrmonk7663]

Thank you. I’ll grab a video soon!

 

[Mrmonk7663]

So I got the 3203 out and about today. About 10 minutes in it died and wouldn’t start. I took off the Japanese superjet carb and fuel wasn’t flowing into it. Tried to free it up and it wasn’t having it. I swapped the jet, pilot and emulsion to my stock carb which has no mixture screw, only idle screw. Started right up. Drove around for around 1/2 an hour with no issues.

Kart drives smooth. I hit 34mph. Should be higher but my torque converter center to center is about 1/8” less than it should be.

I decided to mess with the superjet carb. I freed it up. Bolted it back on and it would barely start after many pulls with the .021 pilot installed. Beforehand it was running with a .024. This is a reworked Japanese carb setup for racing. It seems it is setup to run at high rpms. It doesn’t like low rpms. It ran with the .024 but idling around it fouled up the plug. I decided to ditch the superjet. Put the stock carb back on again, this time with the modified emulsion tube from the superjet, the .021 pilot, and a .038 jet from go power sports. Started first pull and idled fine. The predators do not come with a mixture screw, just a brass plug. Either way it runs great as is.

I ordered a 7” driven and a comet belt. The yerfdog has a non adjustable Center distance and this belt/driven fall within spec of that distance, unlike my 6” driven and belt.

That’s all for now!!!
https://youtu.be/2j7d7G_uZM0

 

[950speed]

Interesting, I am in Austin TX and tried using a .038 main jet and it was way too rich for me. I ended up using a .033 it is weird how our elevation isn’t much different, not the weather and I must use a Jet much smaller

 

[Mrmonk7663]

I haven’t tested the .038 yet. Just idling. Yesterday while riding it had the .035 in but it seemed a tad lean. We will see.

Gopowersports sends out the .038 in their kits and their elevation and temps in Dallas are much like yours and mine.

If it runs worse at WOT with the .038 ill order a .036 and try it.

I’m tempted to just buy a mikuni but time will tell.

 

[Stephen115]

Nice to see another 3203! I'm interested in your steering bushing idea, keep us posted!

 

[Mrmonk7663]

Definitely will. Parts should arrive tomorrow and I’ll see if it’s going to work.

 

[Mrmonk7663]

Parts delayed 1 day by usps. I took the opportunity to do an oil change. Lots of casting crap. I’ll do one more oil change after 30 minutes more of riding then it should be ready for whatever. I installed a drainzit tonight. This will make future oil changes so much cleaner than it went tonight. I’m going to put these on all my karts.

 

[Dat1Guy]

I am very interested in this thread.. I just picked up the same kart/buggy recently and am very excited bout upgrading it some. I don't want a new paint job or anything too expensive or i wont want to ride/drive it. I will of course do preventive maintenance and cleaning(tc etc.) but I want to rip it through the trails without concern for the paint or $300 engine. No fun if I have to worry about scratches/breaking stuff..lol

 

[Mrmonk7663]

Well if you need help or guidance let me know. Almost all parts for the 3203 are available. They are solid karts and with a little tweaking they are very capable.

 

[Mrmonk7663]

7” driven has arrived. Belt comes tomorrow. I will work on the steering slop tomorrow if I get time.

 

[Budget GoKart]

Man i just love seeing yerfdogs restored i have a 3202 with a 420cc subie it was solid and took all the abuse i threw at it but the subie still doesnt run sadly

 

[BigWes]

7” driven has arrived. Belt comes tomorrow. I will work on the steering slop tomorrow if I get time.

Ha! I have one of those waiting for a project to go on... it's just an ugly black one with a 3/4 inch shaft hole it was an expensive little bigger too!

 

[Mrmonk7663]

I’m off on Friday so I should get to test the 7” then. Excited to see the difference. Between a proper ctc and more torque from the 7” it should be a noticeable difference. Assuming it is I’ll be doing the same for the 30032 yerfdog. Still need to make a build thread for that one.

 

[Mrmonk7663]

7” installed. I spaced it out with a machine washer. I cut a keyway into the washer with a dremel. Worked great. The 6” had contact with the chain I found out upon taking it off. Fresh comet 203591 belt to top it off.

The gx140 emulsion tube arrived. I’ll install it with a .037 jet and see how it behaves.

Edit- installed the .037 main with the gx140 tube. Started right up. Idles really nice. With the .021 pilot it prefers half choke to start.

Tip-if you install an emulsion tube with the carb on the bike and it keeps falling down, get a pencil with eraser. Use eraser end to hold the e-tube in place from intake side of carb while installing jet.

While idling the kart my daughter was sitting in it. I told her to wait for me while I stepped inside. She couldn’t resist the temptation and hit the gas. Scared the heck out of her haha.

 

[Mrmonk7663]

Took the dog for a rip today. Hit 37 mph with me and two kids in it...so about 250lbs plus weight of the kart. Theoretical top speed with my gearing and tires at 5k rpm is 39mph so it’s right in line with what it should be doing. With only a header and intake it’s not a speed demon, but it’s not slow either. The 7” added some noticeable torque down low. I need to put a tach on to see the rpms I’m running. It accelerates to 30 very well. After 30 it climbs slower. Better gearing would fix that but I think I’m going to leave it as is. It’s perfect for the wife and kids.

Uneven terrain is quite smooth. I was surprised. Also no problem climbing over curbs and things. A fun yet tame combination. I’m going to throw on a clear valve cover I have and call it a day.

 

[Mrmonk7663]

Clear valve cover installed. This thing is neat. Install was 5 minutes. The main reason I wanted it aside from the cool factor was the stock valve cover didn’t hold the hose in very well and it kept falling off. The clear cover solves this with a hose barb.

I also pulled the spark plug to check it after the new jetting and today’s riding. It looked perfect.

Still need to do the steering slop mods.

 

[JTSpeedDemon]

I wish they made clear breather covers for flatheads, but then again, they'd be mostly hidden behind the carb stuff.

 

[Mrmonk7663]

It’s a functional novelty item but it’s fun to watch haha