“Kop Kart”(police kart)-18Hp Yerf Dog Resurrection; Father/Son summer build

[miniblazinbmx]

Looks good, I just finished a kart myself - had a lot to do on it - I can definitely appreciate what you have going on! I'm sure you'll get it soon!

Thank you! Do you have any pics or a link to a thread anywhere I can see?

 

[miniblazinbmx]

I gotta stop late night shopping..

came across this USB port with a built in voltmeter, figured I had some space leftover to put it in our dash.

I was looking for one to power our GPS speedo so I didn’t have to drain my phones power to tap it on. Since I’m using a power regulator/converter I really don’t have another way to monitor battery life now that the lights won’t dim with low power. I like idea of monitoring my fuel and battery, however we don’t have a gas gauge YET

Blue was a nice touch and overall it’s not a bad idea to have a couple extra power ports to jack into with a phone or something.
Next project will involve a solar panel setup for field charging the drill batteries off sunlight. Technically speaking at that point we can roam much longer with an extra gas can and some extra batteries. Excited for new parts this week, and hopefully get some more progress in.

note: The dash is NOT assembled in this photo*

 

[miniblazinbmx]

Inch by inch.. getting closer. The HF wheel and tire mount tool is every bit worth the $40. All 4 wheels done in less than 10min.
Lights getting mounted..
Final electrical mapping..
New shock install tonight.
That should correct our alignment issue as well as give us a better weight rating.

Definitely a fan of the digital voltmeter tho.

 

[Denny]

I have heard of the charging system putting out between 3 and 18 amps. I would hook the headlights to charging sys with battery. Auxiliary lights to the auxiliary battery. I don’t think solar panels will hold up. Too fragile.

 

[miniblazinbmx]

I have heard of the charging system putting out between 3 and 18 amps. I would hook the headlights to charging sys with battery. Auxiliary lights to the auxiliary battery. I don’t think solar panels will hold up. Too fragile.

Volts are going to be more critical than amps in my case. I am running drill batteries instead of car batteries attempting something new.
I def agree about the solar! Not on a go kart haha

 

[miniblazinbmx]

This heat is unbearable in north Texas right now. Shop is 120 daily. We took the evening off to chill down inside together.
But we did start and finish a little goof off build..

 

[miniblazinbmx]

More loose ends.. finally have the last wheels repainted and cleaned up. They look good and feel good. The bullet valve stem caps are real
.40 Federal hollow points(often used in duty sidearms), and add a little extra touch to the Kop Kart.

Also, our China gas shocks came with only 2 bushings when I need 4. I could drill for the bigger size but why throw out $17 in a G8 hardware upgrade and finish bolts..I think I’ve found some replacements online, but if that fails, I’ve got a friend willing and able to mill down these steel spacers to fit inside the eyelet bushings.

..More electrical mapping and brainstorming..

I’ve been looking at upgrade parts and figure this is a gx390 clone, so most of the 420cc performance parts will work here too. Stay tuned for that adventure. This ought to be fu..

 

[miniblazinbmx]

Aluminum mounting plates in process.. for strobe panels and electrical mounting.

 

[miniblazinbmx]

These past few weeks have been torture as we finally got it fired up and realized we had some major issues to handle. Stil working through some suspension kinks, but we had to go back to drawing board with our drivetrain.
After we smoked our clutch I decided to try the 30 series converter, however we couldn’t get it to fit, so traded it out for a 40 series and restored and tried to use the OG jack shaft housing, only to find out it wouldn’t work either.

I had to basically just go with a custom setup on our driver pulley/jack shaft setup, offsetting it further from the motor and using some leftover tube to gusset the frame and fab a bearing mount location for the shaft. This design allows me to distribute the force and weight evenly across the shaft, and also gives me plenty of room to adjust things how I want in the gear house. It took some time and patience and a lot of trips to the local hardware store, but I did finally cook up something solid that should last and also be easy to work on if needed.

However this feat didn’t come without its hiccups either. In the end it looks like our chain is 2 links too short or 1.5 links too long. The way it’s sized with the 14t cog means it either has too much or too little play, even using a half link. So I’m going to try a bit of regearing and see if we can get a chain and sprocket combo to fit together well again. The assembly turns smooth and looks good, but out of 3 new chains sitting around none are able to be used how I need to them.

This week I’ll be designing and making a TC drive pulley adapter for the driveshaft, begin trimming and mounting our strobe lights and panels.. fix a minor brake adjustment and throttle issue. Align the steering, and finish collecting parts for our stage 1 engine upgrade.

I should mention I am working on a dual a arm design for this specific kart, but that won’t happen for another month or two. Just because.

 

[miniblazinbmx]

I am happy with this latest design. It was cleaner and less work to make something from scratch than try to make original parts work for this. Success nonetheless.

 

[miniblazinbmx]

More pics of the finished product.. (minus chain).

I opted for a couple vertical braces out of some 1” tubing, I kinda prefer keeping the stock looking gussets, and even tho these are not factory, I did add one to the other side for strength and symmetry.

 

[Bansil]

G22? Rectangles.....tell the tale

loving it! I would tighten up the engine turning for a better look scaled down....love how this is going...oh and circuit breakers rule

 

[Bansil]

The vertical bars fit the theme, nice fab work

 

[miniblazinbmx]

The vertical bars fit the theme, nice fab work

Thank you sir.

 

[Millwright]

Looking at your 40 series TC, you might have an issue there.
I'm pretty sure you need to get the " reverse wound" green spring 8f you are installing the driven pulley with the spring on the outboard side.
My TC came supplied with a belt that was too short. In order to get a mounting configuration that worked, I had to increase my center to center distance to 10.5", and order the correct belt.
Still waiting on delivery.
I could of ordered the reverse wound spring, but then I would still be dealing with the belt misalignment when in the final drive position.

 

[Millwright]

This video has a pretty good explanation regarding the reverse wound spring.

Also, hers a screen shot from a comet document.
I believe all 40 TC operate the same, regardless of brand.

 

[miniblazinbmx]

Thank you guys for that tip. I don’t have experience with a custom
Setup and wasn’t aware. I knew if diff springs but I didn’t realize reverse wound was a thing. I believe reverse is yellow and stiffer than stock is green? Had trouble looking for green but yellow comes up.
I’m really tired of waiting on parts..

 

[Denny]

Just turn the driven around and use it as it was designed.

 

[miniblazinbmx]

Just turn the driven around and use it as it was designed.

I don’t have that room. I didn’t set it up that way. If they make a reverse spring then why not try that? If they didn’t make that I might have no other choice, but I prefer the exposed look anyway.

I suppose if they make springs clocked in either direction it’s also designed to be used both ways..

 

[miniblazinbmx]

Another major issue I’ve been fighting with on this early model Yerf Dog(3002) is the faulty suspension design.
At first I was excited and it was a bonus buy bc of it, but when I actually saw how it performed it was obviously inferior for what we plan to use it for.
Caster is something I can do without since the arms are actually mounted at an aggressive angle, it works. However, camber and toe are not as forgiving. I got to looking through designs and see they obviously figured it out as they went, as the spider box models seem to have alleviated some basic design principle issues.
So without getting too deep here, I’m taking a bit of a few diff designs and using it with mine, to keep the simplicity of the classic Yerf Dog style but update its functionality for our use. Basically the spindle bracket has to go, we’ll add bungs and heim joints perpendicular and level to the wheel axis and maybe add a spring there as well.

I’ve stripped an old arm for mock up purposes and testing the designs as I go. Not what I had planned to do originally with this kart, but I think the more aggressive look and better function will suit us well going forward.

Still waiting on a few parts of the puzzle to show up so I can wrap up these modifications and pick back up on wiring.

At least put down time hasn’t been completely unproductive. Our stage 1 upgrade on the 440cc is done, and it sounds insane. Blue flames, backfires, and throaty exhaust.. it’s a good start but we still need to get that governor out after the break in. More pics soon. 🏎