Yerf Dog Spiderbox & Crossfire Internal Reverse Engine Upgrade Package, 150cc, 175cc, 184cc

$799.00
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Finally you can step up your Yerf Dog or yellow Crossfire to be like all up to date buggies. We have developed a bolt-in package for a GY6 reverse engine for your Yerf Dog Spiderbox. or yellow Crossfire This is the GY6 internal reverse engine that comes on all new buggies. With this engine you will need the modifications defined below.

YOU HAVE THREE ENGINE OPTIONS

Engine 1: 150cc Standard stock GY6 Engine with Internal Reverse with stock transmission--GUARANTEED DIRECT FIT with the defined modifications below. You can get this engine with a high performance transmission installed and get more torque and power to your wheels.
Engine 2: 175cc GY6 Racing Engine with Internal Reverse and stock transmission--GUARANTEED DIRECT FIT with the defined modifications below. This engine comes with the 62mm big bore cylinder and piston kit pictured below installed in a bored out case. We strongly recommend the BDX performance transmission for performance engines--Click here to see why.
Engine 3: 184cc GY6 Racing Engine with Internal Reverse and stock transmission--GUARANTEED DIRECT FIT with the defined modifications below. This engine comes with the 62mm big bore cylinder and piston kit pictured below installed in a bored out case and a 3.0mm high performance stroker crank. Call regarding this option. We strongly recommend the BDX performance transmission for performance engines--Click here to see why.

MODIFICATIONS: In order for this engine to work on your Yerf Dog Spiderbox you will need the following:

Yerf Dog Spiderbox Heavyduty Refurb Axle Kit: Your axle sprocket is in the wrong location and cannot space over the sprocket in that direction without lathing and re-welding the hub. If you have the ability to lathe and reweld your axle then you do not need this kit. This heavy duty axle also fixes the Yerf Dog Spiderbox breaking axle problem.
Reverse Shifting Kit: This kit allow you to shift from forward to reverse.
BDX Adjustable Chain Tensioner: This chain tensioner is needed to mount the rear of your new engine to your swing arm.

YOU HAVE POWER PERFORMANCE OPTIONS

Option 1: American made high performance Uni-Filter air filter ensures clean air to your engine and long life. See why a NEW Uni-Filter is MANDATORY for ALL new engines and purchase at this link. Your one year new engine warranty applies only if a new uni-filter is purchased with this engine. If you don't get a Uni-Filter you are guaranteed to be putting dirt into your clean NEW engine. Stock air filters do not effectively filter air and are the number one engine killer for GY6 engines. Don't get an engine without one. See Details

UNI FILTER ASSEMBLE, OIL AND KIT

Option 2: BDX High Performance Racing Transmission and Gates Powerlink Belt: Click here to see detail or add to your order.. If you add this option the parts will installed into your new engine. A Performance Transmission is the difference between a sluggish, slow and inefficient go-kart and a peppy, speedy and powerful go-kart that utilizes the full power of the engine. See details

Option 3: The BDX A12 Cam Shaft changes the power profile of your GY6 engine to provide the optimal balance for both low end grunt and top end speed. If you purchase the A12 Cam Shaft it will be installed and tested in your new engine.

Option 4: 11 Pole Stator, rectifier and harness adapter. With this option you get more power to run your lights and other accessories. If you get this option it will be installed and tested in your engine--Click Here. The engine comes stock with an 8 pole stator. A few small number of vehicles require an 11 pole stator. Call before ordering if you.

Option 5: Performance Exhaust: You can get the BDX performance exhaust for any of the engines above for an estimated 10% to 15% increase in raw power--see video!. Your stock exhaust is restricting your power because the exhaust gases are being squeezed out through a tiny hole. The BDX Performance Exhaust fixes that. If you get a performance engine without the performance exhaust you will be restricting some of that NEW power. To see details or add the exhaust to your order click here. Or see our video to see what this increased horsepower looks like in a race click here.

THE BDX PERFORMANCE TEAM MEMBERS ARE THE GY6 ENGINE EXPERTS IN THE USA. BUILDING AND SHIPPING HUNDREDS OF GY6 PERFORMANCE RACING ENGINES FOR OVER 10 YEARS. WE HAVE A FULL MACHINE SHOP IN VIRGINIA WITH AN ENGINE TECHNICIAN AND ENGINEER. SEE VIDEO

READ ARTICLE ON HOW DISPLACEMENT RELATES TO MORE POWER.
HOW BIG BORE KITS & STROKERS WORK

TAKE A LOOK AT THIS COMPARISON

Stock GY6 Engine

BDX Performance Racing Engine

WE BUILD AND TEST OUR 175CC RACING ENGINE IN OUR FACILITY IN VIRGINIA.

We disassemble your 150cc engine, bore the case to make it larger so that we can install a 62mm big bore piston and cylinder. Then we re-assemble and test your engine.

BORING THE CASE FOR THE 62MM CYLINDER AND PISTON

62MM 175CC BIG BORE KIT

BE SURE TO READ THE ARTICLE ON HOW DISPLACEMENT AFFECTS YOUR POWER.

CLICK HERE TO SEE ADDITIONAL IMPORTANT INFORMATION REGARDING THIS ENGINE.

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