The 11 Best Horsepower 131 Big Bore Kits (2022 reviews)

The Rutu Horsepower 131 Big Bore Kit is the best fully-featured kit on the market today. The rutu horsepower 131 big bore kit works great and it is great for high quality. Make sure this fits by entering your model number. Also, the kit is used for air filter, is built for high performance and it is easy to install.

Above all, the Rutu horsepower 131 big bore kit comes with a wrist pin and there are many more.

Almost all buyers found that the kit will warp when it gets hot. Also, a few say that the kit is a gy6 50cc. Yes, it will for sure fit and work great. To sum up, most customers call the kit suits best, and no one questions it.

Top Customer Quotes:

This fits any 49cc w/gy6 style engine.
Easy installation with racing ac cdi, ignition coil and racing spark plug included.
This comes in 64mm n 69mm for 50cc, digital caliper is also available on Amazon.
This includes everything but jets.

Best For Great Price: Bbr Motorsports Horsepower 131 Big Bore Kit

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The Bbr Motorsports Horsepower 131 Big Bore Kit is capable of outshining several other kit featured in this list in overall features for the price point. The bbr motorsports horsepower 131 big bore kit suitable for air filter, is reliable and it is great with basic mechanics. Make sure this fits by entering your model number. And, it is easy to install and it is ready to ship.

Above all, the bbr motorsports horsepower 131 big bore kit fits the following applications.

Almost all customers opine that the kit will only work on the xr100 and crf100 bikes. And, they strongly agree that the kit makes no mention of setting the ring end gap for the kit. And, a few also found that this is the kit to get for easy bolt on power. To sum up, many have used the bbr motorsports horsepower 131 big bore kit for more than a few months without any complaints, and it shows no sign of giving up.

Why We Like This:

This is designed for a great price and it is used for torque specs.
Delivers what they promise.

RELATED: Best 170 Cc Big Bore Kits

Best With Thread Lock: Top Notch Parts Horsepower 131 Big Bore Kit

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The Top Notch Parts Horsepower 131 Big Bore Kit's high-end materials makes sure that it ages well with use. The top notch parts horsepower 131 big bore kit looks good and it comes with a thread lock. The manufacturer says: We ship directly from the USA, not like some sellers who say they do but don't. And, this is ideal for best quality and it comes with a gasket maker.

Finally, the top notch parts horsepower 131big bore kit is great for fuel filter, is great for head cover gasket and it is good for oil filter.

Almost all customers quickly discovered that the kit is cheaper than anywhere else. Also, a few strongly agree that the kit is perfectly and fast delivered. In addition, they say that the kit is easy to rebuild and parts are available everywhere. Overall, the tone of buyers is very positive and we believe that the kit suits the purpose.

Why We Like This:

Parts fit: 1999 - 2008 honda trx 400ex.
Replaces oem number 12100-kcy-670 12191-kcy-672 13011-kcy-670 13101-kcy-670 90601-ka5-000 13111-kcy-670 12251-hn1-003 12391-kcy-671 14560-kcw-851.
Good brand reputation.

RELATED: Best Big Bore Gasket Kits

Best For Exhaust Studs: Aniro Moto Horsepower 131 Big Bore Kit

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Aniro Moto line of kit comes in a pretty wide variety of styles, so you can definitely find one that suits your individual preferences and needs. The Aniro Moto Horsepower 131 Big Bore Kit is a 76mm bolt pattern cylinder & head, will not fit the 80mm bolt pattern. This is the perfect kit for a rebuild or you can upgrade your 125cc to 150cc. Moreover, the kit comes with complete with valves already assembled.

The kit is great for exhaust studs and it comes with a wrist pin. Most importantly, the aniro moto horsepower 131 big borekit is great for high quality and it fires right up.

One customer says - "It would be nice if there were instructions, but you can easily find a video on youtube. ". Almost all customers opine that the kit is a gy6 or Chinese clone of a gy6 150cc engine, then yes it will work.

Why We Like This:

Fits the 157qmj engines, 76mm bolt pattern 2 1/2" tall head.
It is sturdy and it works well for good quality.
One of the newcomers and featured product.

Best For Head Cover Gasket: Niche Horsepower 131 Big Bore Kit

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If you often find yourself scrambling for a convenient and suitable kit, Niche Horsepower 131 Big Bore Kit should be your first option for buying. In addition, this includes a brand new 89mm cylinder, big bore piston kit, head gasket and base gasket with 2 o-rings. This is a true bolt on kit, no machining or custom work needed, Simply remove your old cylinder/piston and put this kit on. Lastly, the niche horsepower131 bigbore kit works well for head cover gasket and it comes with a wrist pin.

"If your gonna race of try to drag race this every weekend, you should probably go with a higher quality kit. " - says, one customer. Overall, the tone of buyers is very positive and we believe that the kit suits the purpose.

Why We Like This:

Cylinder bore and stroke 89.00mm x 70.00mm.
Compatible with Honda 1996-2004 xr400r, 1999-2008 sportrax trx400ex, 2009, 2012-2014 trx400x.
Includes base gasket and head gasket.
Replaces part numbers: honda 12100-hn1-a70, 12191-kcy-672,13011-kcy-670, 90601-ka5-000,13101-kcy-670, 13111-kcy-670,91301-428-003, 12251-hn1-003,12100-kcy-670, 12100-kcy-670, 12191-kcy-672.

Best For Great Quality: Weiyingsi Horsepower 131 Big Bore Kit

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Compared with other kit in this category, the Weiyingsi Horsepower 131 Big Bore Kit has a convenient design. The weiyingsi horsepower 131 big bore kit comes with a wrist pin and it is perfect for great quality. Manufacturer says: We have 2 versions, 64mm and 69mm valve length version.s. Furthermore, it comes with racing ac cdi, ignition coil and racing spark plug included.

Most importantly, the weiyingsi horsepower 131 big bore kit worked perfectly. It is easy to install and it is good for good quality.

Almost all customers opine that the kit has a 139qmb engine code. Moreover, they say that the kit is made for Chinese scooters. Moreover, a few strongly agree that the kit fits like a glove and also fits icebear well.

Top Customer Quotes:

This is perfect for the intake manifold and there are many more.
This fits on most any 50cc scooter.
This is one of the best upgrades you can make to your 50cc scooter.

Best For Spark Plug: Jdmspeed Horsepower 131 Big Bore Kit

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The Jdmspeed Horsepower 131 Big Bore Kit's material feels more premium than its price would suggest. Further, the kit includes 1x cylinder, 2x gaskets, 1x piston, 1x piston pin, 2x piston rings, 1x sleeve bearing, 2x cir-clips, 4x head cylinder studs, 4x stud nuts, 1x free spark plug. Please make sure to check the fitment below. Finally, the jdmspeed horsepower 131big bore kit looks good, is easy to install and it is perfect for high quality.

"Easy to install if you work on a two - stroke. " - says, one customer. In short, the tone of buyers is very positive and we believe that the kit suits the purpose.

Why We Like This:

New complete high quality 40cc big bore kit.
Delivers what they promise.

Best For These Engines: Goofit Horsepower 131 Big Bore Kit

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Compared with other kit in this category, the Goofit Horsepower 131 Big Bore Kit has a convenient design. Make sure this fits by entering your model number. And, the kit would be perfect with fast shipping and it is great for high quality. In conclusion, with a 3.9 rating and more than 272 buyers, the goofit horsepower131 big borekit stands as the best choice.

Most buyers agree that the kit is an engine swap with a performance upgrade, replacing a 41.5 cc eton powered "big wheel thunder cobra scooter project. In addition, they say that the kit is for any cag style pocketbike.

Top Customer Quotes:

Arrival within 7-15 days (ships from and sold by goofit).
This is best top end for these engines.
Fit for 2 stroke 43cc 47cc 49cc 50cc engine(read description for more fitment infos).

Best For Inner Diameter: Cspart Horsepower 131 Big Bore Kit

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The Cspart Horsepower 131 Big Bore Kit's material feels more premium than its price would suggest. Moreover, it fits perfectly with outer diameter, is great for middle height and it is very nice. It is bored from 107ml (52.4mm) to 125cc(54mm), still called 107ml, but it is a real bigbore kit from your old 110cc cylinder kit. Lastly, the cspart horsepower 131 big bore kit is suitable for inner diameter and it is good for the height of doom.

"Nice kit but will not make 125cc’s out of a 110. " - says, one customer. To sum up, for almost all customers, Cspart product was what they were looking for.

Why We Like This:

Piston kit - total height:39.5mm, compress height:19.2mm, doom deep:2.5mm, pin:13mm.
Cylinder - middle height:69.5mm, total height:93.2mm, inner diameter:54mm, outer skirt diameter:58mm.
Lot of satisfied buyers.

Best For Direct Replacement: Gpa Motors Horsepower 131 Big Bore Kit

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Gpa Motors line of kit comes in a pretty wide variety of styles, so you can definitely find one that suits your individual preferences and needs. The Manufacturer says: You can buy our number 1 quality rebuild kits online, perfectly fitted to your vehicle, This product is produced by Oem factories. Also, the kit is oem compatible for easy installation. To sum up, with a 3.7 rating and more than 56 buyers, the Gpa Motors Horsepower 131 Big Bore Kit stands as the best choice.

Almost all customers agree that the kit fits the Yamaha big bear 350.

Why We Like This:

The cylinder displacement is 348cc, the compression is 9.2:1.
The products are direct replacement parts for hassle-free installation.
New and hot releases.

Best For Big Bore Cylinder: Waverspeed Horsepower 131 Big Bore Kit

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Compared with other kit in this category, the Waverspeed Horsepower 131 Big Bore Kit has a convenient design. The waverspeed horsepower 131 big bore kit is made of high-strength material, can withstand high temperature,sssss high pressure and corrosion for a longer life. Complete 434cc big bore cylinder piston and gasket kit. Further, this is pre-honed and ready to drop in, no modifications required * high-compression hardened aluminum piston kit. Above all, the waverspeed horsepower 131 big bore kit is easy to use and has an excellent design.

"Considering it ’s about 400 dollars cheaper than the name brand. " - says, one customer. Without any doubt, this product passed the test and had very satisfied buyers eager to share their experience.

Why We Like This:

[Part number] - 11191-13e00, 1241-29f00, 12140-29f00, 11210-29f20-0f0, 12111-29f00-0f0, 09160-10082, 11141-29f01, 12151-24f10, 09381-20004.
[Package contents] - cylinder block,piston,piston pin,piston rings,o-ring,head gasket,base gasket,circlips,washers.
Good investment for the long term.