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GY6 Cylinder Rebuild Kits Kymlaa 100cc Big Bore Kit for 69mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring

  • Based on 195 reviews
Condition: New
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Availability: 11 left in stock
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Arrives Sunday, Nov 24
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Features

  • This big cylinder kit will upgrade your gy6 50cc 60cc 80cc to 100cc, without EGR, to get more RPM,more power, faster maximum speed.
  • 69mm valve length version
  • Simple Installation
  • With cylinder body kits, cylinder head kits, camshaft, camshaft seat kits, gaskets kits, oil pump and gear, spring sets, copper roller sets, 6pins racing AC CDI, ignition coil and racing 3-electrode spark plug
  • Upgrades parts kits for most of 50cc scooter

Description

Size:69mm Valve Length Fitment: Jonway 49cc 50cc 4 stroke scooters like warrior 50 50cc 4 stroke like Agility 50,People S50 4T,Suer 8 50 4T Pagsta mini 49cc Baja 49cc 50cc 4stroke scooters like motorsports SC-50 sun city,primo,DR50,Dirt Runner 49 Baotian BT49QT-2,BT49QT-7,BT49QT-9,BT50QT-9,BT50QT-11 Dotera 50QT-11 Eton 49cc 50cc 4stroke like Sport 50 Fly 49cc 50cc 4-stroke scooters Jalon JL50QT-15,JL50QT-16,JL50QT-18,JL50QT-21,JL50QT-21 Falcon. Jinlun 49cc 50cc 4-stroke scooters Roketa 49cc 50cc 4 stroke scooter such Bahama,Maui,Sicily,Tank,Baotian 50QT-9 Sinski XSJ50QT-6, XSJ50QT-B SSR Lazer 5 Moped Sunl SL50QT-16, SL50QT-18,SL50QT-2,SL50QT-3 Tank 49cc 50cc 4-stroke scooters Taotao 49cc 50cc 4 stroke scooter such as GT5,Fastwind,AMT50-A1,CY50-A,CY50-B,CY50-T3,Funny50,Roman 50,Retro 50,Speedy50,Venus50 Verucci VC50TS-3M VIP future champion 4 stroke Zhong Hu 50cc,Zongshen Metro 50cc Zongshen ZS50QT-4 Many more GY6 4-stroke 49cc 50cc 60cc 80cc from china. engine Specifications: Bore: 50mm Displacement:100cc Valve Length: 69mm Pacakage Included: 1 x Set of 6 Gram Racing Pure Copper Roller Weights 1 x Cylinder Head with 69mm valve with Update Camshaft. 1 x Rocker Arms Assembly 2 x Valve Seals 1 x Oil Pump Assy with Driving Gear 1 x 50mm Bore Cylinder Block 1 x Set of 50mm Piston Assy, Piston, Rings and Wrist Pin 1 x Full Set of Engine Gasket 1 x Set of Intake Manifold and Muffler Bolts, and Exhaust locking hat 1 x 6pins Racing AC CDI 1 x Racing Ignition Coil 1 x Racing 3-electrode A7TC Spark Plug 1 x Set of Clutch Small Racing Spring 1 x Racing Clutch Big Spring

Manufacturer: ‎KYMLAA


Brand: ‎KYMLAA


Item Weight: ‎6.6 pounds


Package Dimensions: ‎10.31 x 7.24 x 6.18 inches


Item model number: ‎KYMLAA-00050-1


Manufacturer Part Number: ‎KYMLAA-00050-1


Date First Available: September 24, 2019


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Nov 24

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Perfect fit. Perfect install. Way better power. Great product for the price.
If there is a single bad review on this item it was either a fluke or lack of installer experience. This kit came exactly as shown. Was very easy to install, and took 2 hours total and wasn't even rushing. Watch a few YouTube videos and DO NOT RUSH! Everything went together perfect, and smooth. All parts including exhaust studs were absolutely fine and same as stock. Bike started up within a few cranks once gas got back in to the carb. The power is night and day. Have no problem getting my tao 50 pony up to 40-45mph now, and quickly. Pulls wheelies fairly easily now as well. Literally was getting smoked by my buddies mopeds earlier in the day, and went back to his house after install and put bus lengths on his 2 stroke moped. Much more responsive. Keep in mind I already had an upgraded jet (85) and intake and exhaust and a 7/5gram split slider swap. But literally runs perfect as is with only a small idle adjustment. Highly suggest this kit. I haven't even installed the cdi, clutch springs, or big main engine gaskets either. Only complaint I have is the spark plugs that keep coming with these kits and the cdi kits are trash. Use ur stock plug or a new stock one. Other then that we'll worth the money and definitely a good buy. ... show more
Reviewed in the United States on September 4, 2023 by Amazon Customer Amazon Customer

  • as described Daughter Happy
Bought a 49CC scooter for my Daughter for Collage, But it took 2 blocks to reach 30mph, any hill it would go from 30mph to 10mph (top speed downhill 35mph) not cool. I deemed it to be too dangerous do to the speeds on the roads near the collage was 35 to 45mph in a hilly area. OK so I installed this kit and a aftermarket Exhaust. Now she out accelerates my wife's car from 0 to 20mph top speed 45mph on the flat, going up a 6% grade hill she holds 35mph So this year we took her to the 2024 Sturgis Motorcycle Rally in Sturgis, South Dakota and she rode her Scooter down Main Street with the Big Bad Harley's and Indian's. My Daughter had a blast over 200 miles on this kit. PS took about 3 hours to install this includes watching the videos on how to do it. Good luck and happy Scootering/Biking ... show more
Reviewed in the United States on August 21, 2024 by Steven Peterson

  • Bore kit
Perfect other than the spark plug cable didn't work
Reviewed in the United States on June 11, 2024 by Glenn

  • Valves leak on head low quality
The cylinder head is bad had to order a whole new head the valves are leaking and not seated correctly kit was total garbage rockers were loose too rings are trash
Reviewed in the United States on April 8, 2024 by Christian James

  • Upgrade worth it, some parts didn't work
10/10 worth the upgrade from 50cc. The slight power increase is all I was looking for. Easily get to 20 mph and topped around 35-38. All parts were correct, NOTE NON EGR CYLINDER HEAD, but CDI didn't work. Left the old CDI installed, works fine.
Reviewed in the United States on April 6, 2024 by The Guinns

  • Skill
This big bore 80 kit was intended for my 49 cc speedy amigo. Everything arrived in it's proper packaging. Nothing was missing. Everything fit like it should. It just took a while and it's a very technical job if your not handy. Thanks to YHWH my neighbor is a motorcycle racer/mechanic and without him I could not have done it myself. We replaced everything except the oil rings because it was to hard to get to. If you buy this I highly recommend you change out everything and also get either a bigger carburetor or have it rejetted. Also throw in an after market exhaust and you got yourself a fast lil scooter. Def to fast for me. ... show more
Reviewed in the United States on June 19, 2024 by John waters

  • Best Purchase for my moped
This is by far the best purchase I made for my moped. Before it would take a good 30 seconds just to get to 35mph. Now its under 10 seconds and I stay with the flow of traffic very easily. Just like the other reviews stated, TAKE YOUR TIME AND WATCH PLENTY OF YOUTUBE VIDEOS!!! Rating this as a 4 due to the fact that the intake/exhaust bolts are EXTREMELY easy to snap, like way to easy. Be sure when you are installing it that you install it by hand, tighten by socket wrench and stop when it gets tight. DO NOT OVERTIGHTEN! Also it does not come with the outside rubber cover for the valve head, you must re-use your own. EDIT: Dropping down a star. Purchased another one of these kits to install on my other moped and I realized that the long bolts for the intake were not threaded properly, causing them to not screw in all the way, bend and snap easily. Pretty sure this was why my first one also snapped. If you purchase this, I would make sure your long intake bolts are threaded properly & screws in all the way. Also make sure you can install your intake spacer before you start pulling your motor apart. ... show more
Reviewed in the United States on September 20, 2024 by Ray Mayer

  • Ok
Ok
Reviewed in the United States on September 9, 2024 by John thacker

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