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

miniblazinbmx

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What’s up everyone! New to this forum, and scene, came across this site looking over info for a build I’m currently working on.

As a first time kart builder I wasn’t sure exactly what I was getting into, but I wanted to find a summer project for my 7yr old son and I to work on together, and after some local searching we ended up scooping up this very rough backyard hunk of twisted mess..

Before I say anything more, I do have an extensive background with metalworking and cars, and I WAS looking for something that was going to need work. Thankfully, building a kart seems to be a fraction of the costs of my other projects. As of now we are about a month into a full restoration/modification of our Yerf Dog 3002 Police theme Tribute Kart.

I searched and searched before and never found anything like what we were thinking about, so we’ve pretty much had to sketch it out and make it happen ourselves. Its become such a fun process for us the last couple months that we are tingling with excitement to find some new places and friends to ride with. Here’s a few pics of the progress so far, let us know what you think, or if you have any questions feel free to ask!
-D
 

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miniblazinbmx

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For starters, nothing worked. Brakes. Engine. Steering. Bearings. None of it. I figured at least the chassis was good, and the front suspension was cool looking.. however you can see from
My previous post the frame actually had multiple cracks, and one completely through the engine support brace. One of the control arms was beyond wasted, and the motor was in such ugly shape I just tossed it to the side. It wasn’t even worth my time to mess with it. Of course the closer I looked the more problems I found, and the more I began to feel the heavy sinking of buyers remorse..
 

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miniblazinbmx

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But, after a couple days of brainstorming an attack plan I stripped it down and hauled the chassis to the shop for some repairs and fabrication work.
One thing I notice about every go kart is they are built as cheap as possible. Most hardware isn’t even G5, let alone G8 or hardened steel. This stuff wears out, rusts, bends quickly and easily under the daily abuse of riding. Not to mention the tolerances on most low to mid range karts are unbelievably forgiving.
But it’s the devil in the details..

I plan on juicing this old dog with an 18hp big block, so it needs to be safe and sturdy and as always I would rather overbuild it than under.. at least I know it can take the abuse I plan to throw it’s way.

Frame cracks repaired.
Pedals realigned, reinforced, and re-gripped.
All repairs and color matched parts a slightly darker shade of paint until we can get it dialed in and stripped again for powder coating.
 

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miniblazinbmx

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Brakes are such an issue here, the hardware missing and everything bent or broken. I’m messing with setups and trying to dial it in but it’s going to happen after I figure out engine mounting and some structural issues.
 

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miniblazinbmx

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Im extending the floor for safety and strength, but trying to save weight also. I really enjoy using this 1/4” expanded metal with my personal projects. I’ve built a several things with it now, so It seemed only natural to use some leftovers on the Police kart. I rolled and formed the front grille thinking it would be a nice custom touch, and to add a little aggressive look to the front end. Thoughts?
 

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miniblazinbmx

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A few more build pics from a few weeks ago:
One of the control arms was completely wasted, but we replaced both, and dusted some fresh color on those, as with everything else.

I’ve also decided to dump the factory kill switch and mounting tab, fab up a quick dash panel for the elec start button and aux lighting, and stitch a tube onto the back for a whip flag later on(visibility and racing purposes).

Note: we plan to powder coat the entire kart, but we are also fabbing and adding accessories as we build so for now we’re using a slightly darker shade of blue RustOleum spray paint.
 

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miniblazinbmx

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Here’s a few more..

Still dialing in a minor brake issue as I go and test fit certain parts. Some reinforcing on the seat, color on the wheels, and some detail work for seat access underneath. Planning to try to power the lights and electrical with a 20v drill battery. We’ll see how it goes. It’s much cheaper and lighter than a deep cycle moto battery and charger. 💁‍♂️
 

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miniblazinbmx

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Our engine showed up early last week and immediately noticed the bolt pattern was different.. not only is the DuroMax 18Hp 3x the power and torque, it’s also 3x the size(especially in its stock form).
Due to the extreme crowding of the shaft and motor and brake, I’m offsetting the motor a bit, which meant removing a section of the factory plate.
Originally I had thought about removing the plate and switching the sides of brace it was on, but it was a lot more work and would yield a less appealing result, so i opted to just fab up an adapter plate design, which was going to happen regardless due to the bolt pattern.

the cage is currently being fit and modded for overhead auxiliary lighting, safety features, and amenities. Being the motor is the only thing that can be easily manipulated at this point, the kart is 80% together for mock up, then 1/2 coming back apart for paint and some wiring and electrical detail. Moving along.. ✨
 

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miniblazinbmx

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Just some quick mounting brackets for the overhead light bars, and some test runs at an engine adapter plate design, may be able to to run with this.. I’ll have to mock it in this weekend. Probably taking a short break next week anyway. Things will move slower as the final details are ironed out. Brake dialing, chain sizing and alignment, steering, but mainly electrical. With everything being run by an 18v drill battery and LED’s I’ve gotta wire in extra relays and such also to make the police strobes and sequencing functions work properly. Very tedious work to try and accomplish while simultaneously being pestered about when it will be finished.. haha my son is absolutely all in to ride soon. 18hp is prob going to make him wet his pants but it’ll be worth it to see the look on his face. 😅😎
 

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miniblazinbmx

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Sooo.. how many wires are on your karts? 😬😩

I think im counting close to 60.. lol
 

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miniblazinbmx

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A little more progress this week.. back and forth working on an engine adapter plate. With the big block it left my sprocket and brake feeling crowded so for ease of maintainence and repair later on, I decided to offset the engine a bit, hoping it might also help with weight distribution in high speed turns. Just some brainstorming ideas here with some scrap metal and terrible drawings.

Our cage was bent, so after some pulling and pushing I was finally able to get some of the bow out of it, but it didn’t turn out perfect. I would like to modify the cage later on so for now it’s solid and sturdy. Added some cross bars for strength and also light mounting.
Working currently on a different storage rack design due to lack of access to a tubing bender.

I’ve been thinking a lot about our next build, a different theme. And although I prob should have entered the contests anyway here-I don’t really need or want the pressure. This is fun in my spare time, let me get a few down for practice before I start challenging everyone lol.. you guys have built some amazing stuff I see. I hope our police Kart will be up to par!
Anyway, dumping a few photos here.
Note: pay not attention to the fact the level isn’t level, pay attention to the fact they all match😉

Work with what you’ve got right? We’re working on a garage space this weekend lol
 

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miniblazinbmx

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Ideas floating for removeable engine screens..
And this is where I gave up last night. I don’t have the tools or patience at home to get these mounted I guess. After 45 minutes of fighting only to get one side on one rim I called it quits. Currently researching other methods or places to handle this.. unless you’ve got some ideas? These little tires didn’t stretch at all
 

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