Post by slowcarguy on Dec 12, 2006 21:04:43 GMT -5
I have a rocketa 50 that I picked up this summer and it's been a blast to own since day one. Coming from a import auto performance backround, I had to do a engine swap. I picked up a 150cc gy6 from a new chinese ATV with no miles on it.
Motor mounts were relatively easy, they consisted of two "ears" that come down off a bar that I welded in between the frame just behind the starter solenoid. I removed what was the old motor mount assembly entirely. The shock mounting position was in the same place as the 49cc engine which helped. The trailing arm is about the same legnth as the old one as well because it came from an atv where it doesn't need a longer casting for a swing arm as in the 150cc gy6's found on scooters. This means it's "stock" in appearance.
The most difficult part, and of course that's a relative term, was the fact that I had to swap the driveshaft/axle coming out of the cvt. The 150cc's have a dual rear shock and an 8" axle while stock 49's have a 3" stubby one. I simply took the gear boxes apart and slid the longer axle from the drive gear and replaced it with the shorter one from the original cvt.
Brakes out back were a breeze. The casting has the holes in it for the shoe pivot and the rod that connects to the cable itself already there for you. basically, the shoes are upside-down compared to how they used to be. Don't forget to swap the pivot from the 49cc to the 150cc because the new motor won't have one because the atv has a brake on the rear axle and not within the rim like a scooter does. The original brake cable works just fine out back now.
The exhaust must be fabricated because without the dual rear shock/brackets even a stock 150cc exhaust from a scooter won't have a place to bolt onto. I used 1.25" mandrel bent pipe I picked up locally for $8 a u-bend and I used 3. I welded on a muffler from a 50cc honda pit bike that was given to me and it sounds great.
The only difference between stock and new carbs of course is the size, cable stay and plug for auto choke are the same. The plug coming from the magneto/rectifier was different but the 3 wires were the same color so I simply cut and spliced in the old plug on the new engine.
I can post some pics and or more tech data if anyone is interested. I'm in a total of $375 including the engine, mandrel bends and steel.
This thing is a blast to drive, the torque on such a small frame scoot is amazing.
~Alex
Motor mounts were relatively easy, they consisted of two "ears" that come down off a bar that I welded in between the frame just behind the starter solenoid. I removed what was the old motor mount assembly entirely. The shock mounting position was in the same place as the 49cc engine which helped. The trailing arm is about the same legnth as the old one as well because it came from an atv where it doesn't need a longer casting for a swing arm as in the 150cc gy6's found on scooters. This means it's "stock" in appearance.
The most difficult part, and of course that's a relative term, was the fact that I had to swap the driveshaft/axle coming out of the cvt. The 150cc's have a dual rear shock and an 8" axle while stock 49's have a 3" stubby one. I simply took the gear boxes apart and slid the longer axle from the drive gear and replaced it with the shorter one from the original cvt.
Brakes out back were a breeze. The casting has the holes in it for the shoe pivot and the rod that connects to the cable itself already there for you. basically, the shoes are upside-down compared to how they used to be. Don't forget to swap the pivot from the 49cc to the 150cc because the new motor won't have one because the atv has a brake on the rear axle and not within the rim like a scooter does. The original brake cable works just fine out back now.
The exhaust must be fabricated because without the dual rear shock/brackets even a stock 150cc exhaust from a scooter won't have a place to bolt onto. I used 1.25" mandrel bent pipe I picked up locally for $8 a u-bend and I used 3. I welded on a muffler from a 50cc honda pit bike that was given to me and it sounds great.
The only difference between stock and new carbs of course is the size, cable stay and plug for auto choke are the same. The plug coming from the magneto/rectifier was different but the 3 wires were the same color so I simply cut and spliced in the old plug on the new engine.
I can post some pics and or more tech data if anyone is interested. I'm in a total of $375 including the engine, mandrel bends and steel.
This thing is a blast to drive, the torque on such a small frame scoot is amazing.
~Alex
