Scooter 911 is building two scooters for competition in the Texas Mini Grand Prix for the 2023 season. Garret selected a 2016 Adly Bullseye as his racing platform and Keiffer will be racing a 2016 Genuine Roughhouse sport. In this video we build the engines and transmissions that will power us to victory in the Texas Mini GP formula 7 class.

Both scooters are 50cc two stroke models, are widely available, and have a large selection of cheap performance parts available. One of the goals of this project is to create scooters that perform at a high level on the race track but are still achievable on a budget and without the use of expensive special tools and equipment.

Garret's Adly motor is a loose copy of the "bugeye" Yamaha Zuma (2002-2011). This build started of by removing the old cylinder head, cylinder and piston. The teardown revealed some scoring damage on the piston and cylinder possibly from a lack of oil or the use of a low quality oil. The NCY big bore cylinder kit used in this build increases the size of the motor from 49cc to 72cc buy utilizing a larger piston and cylinder. The cylinder features a larger and better flowing exhaust port. The cylinder head has a machined squish band for better compression and more power.

Keiffer's Genuine Roughhouse utilizes a horizontal Minarelli engine but there are some specific differences between the Roughhouse motor and other Minarelli's. The oil pump and intake manifold are unique to the Genuine 50cc engines (manufactured by PGO).

The Genuine Minarelli platform differences don't just stop at the oil pump and intake. The transmission is also very unique. It utilizes clutch and variator components used by the GY6 139 QMB and the Honda DIO. This is different from most Minarelli motors which typically use components developed for the Yamaha Jog.

Here are the parts installed on Garret's "Radly" so far:
NCY 72cc Big Bore Kit - https://scooter911.com/shop/ncy-cylin...
NCY Super Transmission Kit - https://scooter911.com/shop/ncy-perfo...
NCY Expansion Chamber Exhaust - https://scooter911.com/shop/ncy-perfo...
NGK Spark Plug BPR7HS - https://scooter911.com/shop/spark-plu...
Malosi CDI - https://scooter911.com/shop/malossi-c...
Coil-on-plug ignition - https://www.scooter911.com/product-pa...
Genuine 2-Stroke Oil - https://scooter911.com/shop/genuine-2...

Here are the parts installed on Keiffer's "Racehouse" so far
NCY 72cc Big Bore Kit - https://scooter911.com/shop/ncy-cylin...
NCY Super Transmission Kit - https://scooter911.com/shop/ncy-super...
NCY Expansion Chamber Exhaust - https://scooter911.com/shop/ncy-perfo...
NGK Spark Plug BPR7HS - https://scooter911.com/shop/spark-plu...
Genuine 2-Stroke Oil - https://scooter911.com/shop/genuine-2...

For more information on the Texas Mini Grand Prix check out https://texasminigrandprix.com/

If you're in Austin Texas and you're looking for scooter, motorcycle, moped or ATV repair check us out at scooter911.com!

The backing tracks used in this video at 6: 45 and 20: 55 Were produced by the incomparable Kaichow Lau. You can find more of his music on soundcloud at:   / kaichowlau  

The backing track used in this video at 10: 59 is "Mittens Made a Boom Boom" by the implausibly talented Matt Keiser. You can find more of his music on instagram:   / kattmeiser  

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00:00 - Intro
01:04 - "Radly" engine teardown
03:47 - Installing the "Radly" big bore kit
06:42 - "Racehouse" engine teardown
09:24 - Installing the "Racehouse" big bore kit
11:00 - Building the "Racehouse" transmission
15:49 - Building the "Radly" transmission
20:54 - Installing "Racehouse" exhaust
21:33 - Installing "Radly" exhaust
22:58 - Wrap up