PCB Chopper

Greetings & salutations from Panama City Beach! This project started out about 2 years ago with this dumpster dive diamond. I had a dream...



Can you REALLY polish a turd???

Watch me!

A few months & a sizable tax return got me this far.


$700.00 so far and still no motor. I'm not even halfway there yet!

Enter motor. Grubee GT5 Super Rat. 66cc, advertised 3HP out of the box.



A little polish, a little paint.



Modding the sprocket to clear the coaster brake.



More to come!

So far I have a GT5 on a Schwinn. Technically it's an outlaw, too many CCs & unregistered. Still I managed to clock over 500 miles looking like this.



Got tired of being hassled by 'the Man', went to get it registered. Nope, uh uh, not gonna happen. It has to have all the safety equipment as a motorcycle, on a MOTORIZED FRAME! Once a bicycle, always a bicycle.

So I got a motorized frame. A Skyhawk GT2A from the same distributor as the motor, Gasbikes.net. It has a built in fuel tank, motor mount, and a 17 digit VIN stamped into the cranktube. Be kinda hard for the DMV to argue against that.



But I still need electrical. I can do that.

Okay, I did a little more than just spit & polish. I painted the flame treads with red urethane, got axle spikes for the front, added the yellow safety reflector tape, disc brakes.



Intake extension, braided fuel line, K&N style air cleaner & home made clutch roller. I also port matched the manifolds. Seems to run a little stronger.



Legally I HAVE to have a mirror. Why not a cool one? To match the grips, tires & paint.



The electrical system is all hidden inside this custom battery box slung under the saddle. I gotta key and everything. Inside it is a battery, a couple of relays, flasher, horn & fuses, and a voltage rectifier for the 12v AC friction drive dynomo.

Went riding on it today. 1st time it's seen fuel in months, not since the engine was still bolted to the Schwinn. Spent 1/2 the day just running laps in my neighborhood, tuning it up, playing with the needle jet in different positions. I wanna get a decent torque pipe, maybe play a little with the timing and shave the piston a bit. I wanna be able to do at least 40, but instead of building a high revving screamer, I'd rather build one with good low & midrange grunt, and gear it up with a smaller sprocket. Keep the RPMs down. Speed=friction, the faster it runs, the shorter the lifespan.

I've looked into a better ignition, but unless I swap the motor for another HT ChinaGirl, I'm stuck with the stock one piece CDI-magneto, and supposedly the Super Rat has better bearings anyway. So it looks like I'll be shaving woodruff keys and playing with my timing the old way. It does about 35 now, but I'm a lightweight, only 150 lbs. Bike is around 60. I don't think this motor's living up to it's full potential just yet. The intake extension needs to be a little longer, but I'll need a longer throttle cable 1st.

But for now, It's good enough to pass inspection & get tags. I got a GT2 motor tag to say it's 48cc, it has everything the law requires to be registered as a moped, full lights, reflectors & horn, motorized frame, I think I'm ready.

Wish me luck. I'm gonna call the DMV & schedule an inspection to get it registered this week.

2door said:

You've probably read this here but let me remind you that these little engines need some miles to start seeing their full potential. I like to see at least 200 and 300 is even better before I start playing with performance enhancments. The rings don't seat quickly and that's one thing that will increase power output. The compression will go up and that alone will help. Give that little guy a chance. If you're seeing 35 now, 40 isn't out of the realm of posibility.

God luck. Keep us informed.

Tom

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FYI, I burnt up over 5 gallons of fuel last year as a Schwinn Outlaw. It's been several months to transform it on the GT2 frame, had to upgrade multiple componante to get it all to work. The GT2 takes a bigger headtube & pedal crank bearings, the top tube is longer, so rather than cut & splice my existing wiring, I started over from scratch. THAT took months.

I only burn ethanol-free super unleaded in it, with 32:1 outboard 2cycle, prolong fuel stabilizer & a pinch of 104+ octane boost(maybe 1/2 oz per gallon), as I've learned while Schwinning around it likes the leanest mix I can dial in for power & speed, and the cheap $#!+ makes it ping bad.

It's broken in good, but I'm tempted to pop the jug & clean up the ports, knife edge the bottom transfer ports & see if there's any flashing or gaskets in the way, impeding the flow of gases. There's already 2 jug gaskets from the factory, if I only use one I might be able to boost my compression a bit, but doing so would also alter the timing, lowering the ports. While I'm no stranger to motors, this is my very 1st 2stroke I've played with, so I'm unsure of whether this mod would benefit me or not, or to what extent.

WoodyFlorida said:

Two seriously cool builds, I love the attitude. Well planned and executed too. I can imagine
how much fun it is cruising Front Beach Rd. Thanks for sharing i appreciate it and look forward to more. Watch out for those PCB cops.

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2 builds? How you figure? Unless you count the krate bike as 1 build, then motorizing it as the 2nd. Or do you consider the Schwinn the 1st & the GT2 the 2nd?

It IS fun cruising Ft. Beach, especially when everyone stares, points & gawks. When I do drive it (been too cold lately) folks always ask me where I got it.

And yes, PCB cops can & have been most unfriendly regarding the lack of legal registration, which is why I sprung for the GT2 frame, it's made exclusively for motorizing(major sticking point with the DMV), which should help me clear the legal hurdle towards getting tags.