A few weeks ago I got this 50cc mini quad in exchange for doing some small engine work for a neighbor. He never had it running, it had no carb, throttle cable or fuel tank or even spark for that matter! The plan is to bring it up to snuff and sell it.
A couple weekends ago I started working on getting spark and nothing. I went through the wiring, removed the remote kill box, checked for power coming out of the primary coil, all of that was checking out but the blue/white wire for the crank trigger was grounding out and wasn't sending a signal! I opened it up and it was obvious someone had been into it at some point because I found not only was that wire pinched to the point of grounding but it was basically severed! One of the yellow wires was also pinched but it didn't pierce the insulation. I ended up robbing the crank trigger from a spare motor, soldered it in...
... and still no spark! I'm looking over the wiring again and what do I find? A tethered kill switch hiding out behind the battery box! Once I capped that switch there was fire! Obviously the crank trigger would've still been a problem if I hadn't fixed it already.
Last weekend I dug through my parts and found a carb that not only was the right one to fit but has the spring loaded choke and plate to work with the handlebar mounted choke lever. I also found I already had the right throttle cable and I stole the air filter for The WarHorse (and ordered another) seeing as how I won't be needing it for awhile.
I taped a fuel tank from a pocket crotch rocket on it so I could get it running and start testing/tuning it, I got it running on my lift table, went to put the rear plastics on and it died! Take the plastic off, start it up and as I'm putting the rear plastic on it shut down again! So I start it up again, start moving wiring around and it's quits! Turns out the connectors metal tabs are loose for the rectifier and for the cdi (separate parts) so a little tweaking and it was good to go! I ripped the heck out of that thing, I'm actually surprised it hauled me around so well and it's quicker than I expected!
Fast forward to this week and I've custom mounted a larger fuel tank. I searched all over the web and Amazon, I ordered the one tank that looked like it was the right one but with my luck it wasn't! Lol.
Here's the new rear mount, I drilled and tapped holes for some Allen bolts...
... and one of the front mounts. I cut a couple tabs off an old ATV frame, trimmed them to fit and welded them on.
Here's the tank all mounted up finally!
Some trimming of the front plastic is required to fit the tank, I've just been removing a little bit at a time and am getting close but still have more work to do (it should sit on top of the lights).
This is how it sits as of tonight.
There's still alot of work to do before teardown and paint but at least it's running and driving now!
A little bit of tinkering the last couple evenings and the plastic is trimmed to fit well around the tank.
I also warmed the sides of the plastic with a propane torch to help mold it better. I used a cargo strap to pull it in from the sides while I did it.
The tires I ordered a couple weeks ago came in and they look awesome! The old ones are pretty worn and cracking so I figured some new ones would help the curb appeal and resale value.
Well I'm finally back to work on this thing, it's the perfect time of year to sell it so I'm hoping to have it done and sold by this weekend!
First step, tear down! Once it was torn down I cleaned and prepped the frame then sprayed it with bedliner, not only does it look great but it's really durable so yes, I use it for almost everything! Lol
The rear swing arm had a piece missing and some cracks so I dealt with that and painted it. To fill the missing piece I found a little scrap of steel that was about the same thickness as the tubing and took my time welding and bending it as I went.
When I went to prep and paint the front axle/swingarm I noticed cracks in it as well so they got the same treatment!
While they were drying I cleaned up and painted the wheels, I figured gold would look good with the purple and go well with just about any color someone might want to paint the plastics!
Then did a little reassembly and called it for the day!
I touched up the top of the engine with silver paint because of some corrosion and flaking paint.
I cleaned up and painted the rear axle, handlebars and exhaust. The only chrome I could save on the exhaust was the tip and the heat shield bolts! Lol. The rest of it got scuffed up really well then a few coats of high heat Rustoleum flat black paint, it turned out better than I hoped!
I reinstalled the engine, carb, handlebars, rear axle, front spindles, wheels, installed new tie rod ends, a new NGK spark plug and started hooking up some of the wiring and then packed it in for the day.
Well I've been plugging away on this sorting stuff out, painting more parts and getting it running again!
Top speed is actually a little scary on this as it's really unstable at 30MPH! I'm sure glad I gave the brakes a really good going over or I probably would've ended up in the lake! Lol.
I'm not so sure I'll have it ready to sell this weekend, I do want to make sure that everything is 100% so it's good for the new owner and I'm being kind of picky about stuff but I have put a local ad up to start generating interest.
I figured out why it's unstable at speed and have corrected it although I still don't think it will be non-sketchy at 30mph.
The swingarm bolt is 10mm (all metric on these things) and the hole in the mounting plates was wallered out, no amount of tightening can stop it from waggling around.
I used an inside micrometer to determine that the actual tubes ID is just a hair over ½" so I started rummaging around and found some ½" OD tubing but the bolt wouldn't fit in... some more rummaging and I found a perfectly sized axle to slide into the tube and it's already the right length! I'm sure glad I haven't gotten rid of all the spare mini bike parts!
After some Dremel work and drilling, the tube fit through the modified holes in a hammer fit fashion so its nice and snug in there! After cutting, griding and deburring the ends of the sleeve I made I put it all back together, low and behold the slop is gone! There's just a tiny little bit of play, nothing to be concerned about and it's probably the same if not better then factory at this point plus that sleeve is made from tubing that is readily available at most hardware stores!
Now I can set up the chain slack and alignment (again) so I can continue testing it today, it's coming along really well and is actually pretty fun to rip around on!
Well, this build is just about wrapped up now, all mechanical and electrical is sorted out and it's 98% reassembled, just a couple finishing touches to finish up and it's done. It was too overcast to get pictures today but hopefully tomorrow I can get and post some!
Finally 100% done and ready for sale! Sleeving the rear swimgarm made a huge difference and it actually does feel pretty stable at top speed now but I still think the throttle should be limited via the thumb throttle screw.
I only had a couple nibbles this past week, hopefully now that's it's done I'll get an actual bite!
Time to wrap up this build thread as it's found a new home, a fella came 3 hours to buy it for his 7yo daughter so she can learn to ride!
I got a fair price, he got a fair deal and his daughter has a solid little quad to play with so everyone wins today! I'm almost sad to see it go because it's a blast to rip around on but I'm just glad it found a good home!
Subject: 
June 15th 2022, 12:13 am
I went through the wiring, removed the remote kill box, checked for power coming out of the primary coil, all of that was checking out but the blue/white wire for the crank trigger was grounding out and wasn't sending a signal! I opened it up and it was obvious someone had been into it at some point because I found not only was that wire pinched to the point of grounding but it was basically severed! One of the yellow wires was also pinched but it didn't pierce the insulation. I ended up robbing the crank trigger from a spare motor, soldered it in... 
