GY6 Cylinder Rebuild Kits Trkimal 47mm 80cc Big Bore Upgrade Kits for 49cc 50cc 139QMB Engines 64mm Valve scooter moped parts, GY6 Engine parts for Chinese Scooter(64mm Valve Length)
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GY6 Cylinder Rebuild Kits Trkimal 47mm 80cc Big Bore Upgrade Kits for 49cc 50cc 139QMB Engines 64mm Valve scooter moped parts, GY6 Engine parts for Chinese Scooter(64mm Valve Length)

4.2/5
Product ID: 161196661
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🔥64mm high-performance valve
🛵80cc big bore upgrade
⚙️47mm precision bore
Frequently Bought Together

Description

⚡ Upgrade your ride, dominate the streets!

  • POWER PACKED 80 CC UPGRADE - Transform your 50cc scooter into a street beast with a high-performance 80cc big bore kit.
  • PRECISION 47 MM CYLINDER BORE - Engineered for optimal combustion and enhanced throttle response.
  • COMPLETE REBUILD KIT INCLUDED - All essential parts from piston to ignition coil—no extra purchases needed, just install and ride.
  • 64 MM VALVE LENGTH FOR MAXIMUM FLOW - Boost airflow and power with extended valve length designed for peak efficiency.
  • UNIVERSAL FIT FOR POPULAR GY 6 ENGINES - Compatible with top Chinese scooter brands like Roketa, Taotao, and Jonway—join the elite riders upgrading now.

The TRKIMAL GY6 Cylinder Rebuild Kit offers a comprehensive 80cc big bore upgrade featuring a 47mm cylinder bore and 64mm valve length. Designed for 49cc-50cc 4-stroke GY6 engines, this all-in-one kit includes every essential component—from piston assembly to ignition coil—ensuring a seamless performance boost for popular Chinese scooters, ATVs, and go-karts.

Specifications

ManufacturerTRKIMAL
BrandTRKIMAL
Item Weight9.38 pounds
Package Dimensions11.3 x 7.8 x 6.8 inches
Item model numberTRKIMAL-00039-1
Manufacturer Part NumberTRKIMAL-00039-1

Reviews

4.2

All from verified purchases

A**

Good Quality With a Nice Power Upgrade

Great as it (almost) has everything needed in one kit for a good price. After watching Roush's video, I got this installed in around 5 hours.Important note #1: keep in mind this kit includes no carb jets, which I did end up needing for reliability and performance reasons. I live at sea level, and an 85 main jet ended up being perfect for me. This is with a stock exhaust, and a stock carb/intake. If you have aftermarket items there, you will need more fuel.Important note #2: I ordered a 64mm valve kit as 64 vs 69 has little to nothing to do with impacting performance unless you will be porting. This ended up making a little more work for me, as my original motor came with 69mm valves (the gy6 uses both 64 & 69mm in different scooters). This was no big deal as the kit came with rockers for the 64mm setup, but required a bit more hassle in disassembling the rocker assembly and changing them out. This is something only a few tutorials show/go over, and can be tricky. Try to find out your valve length before ordering to save the hassle.The 8.5 gram rollers included with this kit were definitely a bit too heavy, and were not allowing the bike to get into its power band. I switched those out for a set of 6.5 gram rollers, and she now rides like a dream. This cost me a few mph in top speed, but the hill climbing and responsiveness improvements are well worth it.Overall I'd say this current setup feels about 1.8-2x the power over stock, and is well worth it. Next I'm going to be doing a few transmission upgrades as the stock definitely feels like it's sluggish/underperforming. This will include a new variator, clutch, and contra spring for rpm control. I made these upgrades on another scooter of mine and saw huge improvements. After will be a new exhaust and possibly a carb. Good luck and have fun!

P**J

Performance ratio

Put this part on my scooter and when the mechanic told me it was ready in a day I was shocked. The acceleration dramatically increased from 7.5 seconds to 2.8seconds. I went 32 mph in 2.4seconds last night. However the parts need to be worn some more so for the next two weeks I will keep top speed of 18mph even tho i can go faster.Note: this 80cc kit works best only if you upgrade 5/5 performance parts : racing Muffler, carburator filter, racing clutch kit (sliding rollers sold separate), racing secondary gear transmission, and 80cc kit or bigger bore to your motorcycle this method applies to all motorcycle, scooters, mopeds, atv , and dirt bikesAll together you should spend about $290 in all 5 parts including its assembly and a good mechanic about $250If you're looking to upgrade and go up the hill 35mph you can do all this and save money and timeI will leave an update for the future on this bigger bore upgrade for 49/50cc scooters

A**N

Relatively easy upgrade, and BOY THE POWER

I'm a mechanic, and I did the swap in my shop. I consulted the Roush's Garage video on youtube (helpful reference guide) and knocked it out in about two hours. It's easier if you elevate the scooter to a good working height. When you do your break-in procedure, make sure the engine is hot and has just been running for your first and second oil changes. Makes a difference in how much contaminant debris is suspended in the oil. If the engine is cold and hasn't been running, a lot of that debris settles and doesn't come out when you drain the oil.The power increase: what can I say? Given that 80cc kits are actually 72cc, it's only a 45% increase in displacement from a 49.5cc bore. But it FEELS like a full doubling in power, if not more. The torque curve is definitely better for take-off and accelerating up to 25mph than the stock engine. I can easily get up to 40, hills are no longer a nightmare, and I don't feel like I'm holding up traffic on my commute. Top speed with 5g sliders, a 2000RPM clutch and yellow contra spring, and stock final drive gears is 45 or so.70 miles on the upgrade so far, and no problems or complaints. All the extra parts thrown in the box are a nice convenience too.

T**C

Poor quality parts.

Moped ran for 2 weeks the started having problems cranking. Got low compression. The intake valve guide was oversized, allowed the valve guide to wear and begin kicking the valve sideways losing compression. Also shims under valve springs were never installed. Tappet adjusting screw had defective threads also.

M**K

Nice kit. Great fit.

This was the way to go. Get a complete kit so everything matches. The cam I received got banged around during shipping so I ordered a A9 cam to replace it with from glial off amazon as well it was perfect upon arrival. Everything went together well not a single fitment issue. And it made a big difference in the power. I am doing all this to a brand new scooter. Let’s say it left a bit to be desired. Most of which really was carburetor issues. Put a Japanese carburetor on it and with a little more jetting work and patience I should see a massive improvement.For the money you just can’t go wrong.This is why I bought the scooter to begin with. It’s just a project to prove it can be made into something fun and reliableKeep in mind the Chinese scooters are not so bad , they are just mass produced on assembly lines. And this kit is the beginningPoint.Don’t hesitate it’s worth the money.

D**E

Great seller

Item was exactly what the description said. Fast shipping and reasonably priced for what all came in the kit. Bore out kit for a scooter. Excellent and honest seller. Would definitely buy from them again. A+++

M**S

A great kit for your buck

This is great if you feel the need to refresh/revitalize/upgrade your scooter. The rebuild components come in handy as spare parts or just improving reliability of the moped. I will purchase this again in the future.

C**

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TrustScore 4.5 | 7,300+ reviews

Suresh K.

Very impressed with the quality and fast delivery. Will shop here again.

4 days ago

Sneha T.

Received my product in pristine condition. Great service overall.

1 month ago

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Trustpilot

TrustScore 4.5 | 7,300+ reviews

Ali H.

Fast shipping and excellent packaging. The Leatherman tool feels very premium and sturdy.

1 day ago

Farhan Q.

The delivery time was excellent, and the packaging was secure.

2 months ago

Gy6 Cylinder Rebuild Kits Trkimal 47mm 80cc Big Bore Upgrade | Desertcart Ireland