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Bullfrog Pro Velocity High Performance Air Filter Kit for Honda GX390 Bullfrog Pro Velocity High Performance Air Filter Kit for Honda GX390

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Fuel Filter, 90 Degree 1/4" OD Barbs Fuel Filter, 90 Degree 1/4" OD Barbs

Fuel Filter, 90 Degree 1/4" OD Barbs. Fits 1/4" ID fuel line

Our Price: $6.10
Main Jet Performance Upgrade Kit For GX390 and Predator 420cc Main Jet Performance Upgrade Kit For GX390 and Predator 420cc

Our main jet kit is a must for the Honda GX390, Predator 420cc engines that have had the performance K&N style air filter setup installed on the engine. Maximizes the engine for best performance and air fuel ratio.

Our Price: $8.14
Fuel Filter, Stainless Steel Element 1/4" Barbs Red Color Fuel Filter, Stainless Steel Element 1/4" Barbs Red Color

Fuel Filter that has a Stainless Steel Element with 1/4" Barbs to fit 1/4" ID fuel line. Red Color

Our Price: $8.30
Fuel Filter, Stainless Steel Element 1/4" Barbs Green Color Fuel Filter, Stainless Steel Element 1/4" Barbs Green Color

Fuel Filter that has a Stainless Steel Element with 1/4" Barbs to fit 1/4" ID fuel line. Green Color

Our Price: $8.30
Fuel Filter, Stainless Steel Element 1/4" Barbs Blue Color Fuel Filter, Stainless Steel Element 1/4" Barbs Blue Color

Fuel Filter that has a Stainless Steel Element with 1/4" Barbs to fit 1/4" ID fuel line. Blue Color

Our Price: $8.30
Fuel Pump, Aftermarket Walbro Pulse Type Fuel Pump Fuel Pump, Aftermarket Walbro Pulse Type Fuel Pump

Aftermarket Walbro fuel pump for Clone engines, Predator 212cc engines, Ducar small block engines and many big block Honda GX390 engines.

List Price: $11.44
Our Price: $9.95
Sale Price: $8.96
Savings: $2.48
Head Gasket Fits 420cc Big Block Engine Head Gasket Fits 420cc Big Block Engine

This head gasket will fit the Predator 420cc and many other 420cc big block clone engines.

Our Price: $12.95
Fuel Filter, 90 Degree 1/4" OD Barbs (Pack of 3) Fuel Filter, 90 Degree 1/4" OD Barbs (Pack of 3)

Fuel Filter, 90 Degree 1/4" OD Barbs. Fits 1/4" ID fuel line. Pack of 3 filters!

Our Price: $12.95
Fuel Filter, Stainless Steel Element 1/4" Barbs Red Color (2 Pack) Fuel Filter, Stainless Steel Element 1/4" Barbs Red Color (2 Pack)

Fuel Filter that has a Stainless Steel Element with 1/4" Barbs to fit 1/4" ID fuel line. Red Color (sold as a pair)
Save $$$'s with this 2 pack vs. buying in singles!

Our Price: $15.95
Fuel Filter, Stainless Steel Element 1/4" Barbs Green Color (2 Pack) Fuel Filter, Stainless Steel Element 1/4" Barbs Green Color (2 Pack)

Fuel Filter that has a Stainless Steel Element with 1/4" Barbs to fit 1/4" ID fuel line. Green Color

Pack of 2 fuel filters!

Save $$$'s with our 2 pack vs. buying individually!

Our Price: $15.95
Fuel Filter, Stainless Steel Element 1/4" Barbs Blue Color 2 Pack Fuel Filter, Stainless Steel Element 1/4" Barbs Blue Color 2 Pack

Fuel Filter that has a Stainless Steel Element with 1/4" Barbs to fit 1/4" ID fuel line. Blue Color

Pack of 2 filters!

Save $$$'s with our pack of 2 filters vs. buying individually!

Our Price: $15.95
Air Filter Adapter for Mikuni 38mm Super BN Carburetor Air Filter Adapter for Mikuni 38mm Super BN Carburetor

Bullfrog Performance Products air filter adapter for Mikuni 38mm Super BN carburetor.

List Price: $38.95
Your Price $27.50
Sale Price: $19.95
Savings: $19.00
Stainless Steel Exhaust Valve 31mm Head for Honda GX390 Stainless Steel Exhaust Valve 31mm Head for Honda GX390

Bullfrog Performance Products stainless steel exhaust valve for Honda GX390 engines. The stock size exhaust valve is a 31mm head diameter in a Honda GX390. We offer cylinder head machining services to maximize head flow for better performance.
We highly recommend this valve when using high lift aftermarket racing cams to prevent valvetrain failure. Our valve will put your valve spring installed height and coil bind clearances in the proper range when using our billet valve spring retainer kit.

List Price: $25.88
Our Price: $22.50
Sale Price: $20.25
Savings: $5.63
Stainless Steel Intake Valve for 460cc, 40mm Head Stainless Steel Intake Valve for 460cc, 40mm Head

Bullfrog Performance Products stainless steel intake valve fits 460cc big block engines when cylinder head is machined for this valve size. We offer cylinder head machining to install this larger valve into the 460cc cylinder head. The valve head diameter is 40mm, which is 5mm larger than the stock 460cc valve. We highly recommend this valve when using high lift aftermarket racing cams to prevent valvetrain failure.
Be sure to include our billet aluminum or titanium valve spring retainer kit with our valve.

Our Price: $21.95
Stainless Steel Exhaust Valve 33mm Head Diameter GX390 Stainless Steel Exhaust Valve 33mm Head Diameter GX390

Bullfrog Performance Products stainless steel exhaust valve for Honda GX390 engines when valve seat is machined to 33mm valve head diameter. We offer cylinder head machining services to install our 33mm exhaust valve in your cylinder head.
We highly recommend this valve when using high lift aftermarket racing cams to prevent valvetrain failure.
Head Diameter = 33mm
Valve Overall Length = 3.650"
Tip Length = .130"

Be sure to purchase our titanium retainer kit or billet aluminum retainer kit to work with this valve!

Our Price: $21.95
Header Kit, GX390 Mud Motor Header w/Muffler Straight Header Kit, GX390 Mud Motor Header w/Muffler Straight

Mud Boat header kit that fits the big block Honda GX240, GX270, GX340, GX390, Predator 420cc and 460cc engines. Our header kit features 1 1/4" O.D. header tube and is TIG welded for best durability. Our header kit includes the following components:

  • Straight header tube to fit mud motor specifically
  • Our custom TIG welded header flange
  • Screw on muffler

Our Price: $36.00
Header Kit, GX390 Mud Motor Header w/Muffler Angled Header Kit, GX390 Mud Motor Header w/Muffler Angled

Mud Boat header kit that fits the big block Honda GX240, GX270, GX340, GX390, Predator 420cc and 460cc engines. Our header kit features 1 1/4" O.D. header tube and is TIG welded for best durability. Our header kit includes the following components:

  • Header
  • Our custom TIG welded header flange
  • Screw on muffler

Our Price: $38.00
Piston Ring Set, 90mm for Bullfrog Performance Products Forged Piston Piston Ring Set, 90mm for Bullfrog Performance Products Forged Piston

Piston ring set that fits our Bullfrog Performance Products 90mm diameter forged pistons with 1.100" compressrion height.

Our Price: $44.00
Bullfrog Pro Velocity High Performance Air Filter Kit for Honda GX390 Bullfrog Pro Velocity High Performance Air Filter Kit for Honda GX390

Our Pro Velocity high performance air filter kit fits Honda GX340, GX390, Predator 420cc and 460cc big block clone engines. Upgrade your go kart, mini bike or drift trike with our high performance air filter kit. Our kit includes the following items:


  • High flow racing style air filter 4" filter length
  • Foam Pre-Filter
  • Radiused air filter adapter
  • Choke hold bracket

Our Price: $44.95
Tachometer, Vegas Carts 0-8000 RPM Tachometer, Vegas Carts 0-8000 RPM

A great addition to any Big Block Kit or Performance Go-Kart where a sweeping analog Tachometer is desired. This Tachometer has been specifically designed for small engines with a magneto ignition such as the Predator 212cc, GX390 or 420-460cc Clone and V-Twins such as the Briggs Vanguard or Predator 670cc. Hooks up to the Kill-Wire on the ignition coil.

RPMs from 0-8000. This gauge is equipped with a Backlight.

Mounting bracket for steering column and wiring pigtail included.

85mm Diameter (3.33")

Fully Adjustable & Tunable

Excellent Alternative to the EQUUS 8068.


List Price: $57.44
Our Price: $49.95
Savings: $7.49
Titanium Valve Spring Retainer Kit Honda GX390 Big Block Titanium Valve Spring Retainer Kit Honda GX390 Big Block

Titanium valve spring retainer kit that fits the big block Honda GX240, GX270, GX340, GX390, 420cc Predator (non-hemi), 460cc Vegas Carts engine (equipped with our stainless steel valves). This titanium valve spring retainer kit includes (2) titanium valve spring retainers and a set of our automotive bead lock style valve locks. Our retainers will fit the single or dual springs out on the market and we also carry them in stock at Bullfrog Performance Products warehouse.

Our Price: $49.95
Stainless Steel Valve and Titanium Retainer Kit GX390 Stainless Steel Valve and Titanium Retainer Kit GX390

Our big valve kit for the Honda GX340 / GX390 includes the following components:


  • 40mm head stainless steel intake valve 3.650" length
  • 33mm head stainless steel exhaust valve 3.650" length
  • Titanium valve spring retainers
  • Automotive bead lock style valve locks
Our kit does require your head to be machined to fit these valve head sizes. We do offer cylinder head machining at our facility and can machine your cylinder head or purchase a fully machined cylinder head from us ready to go.

Our Price: $64.95
Mud Motor Exhaust Header for Honda GX390, Predator 420cc Big Blocks Mud Motor Exhaust Header for Honda GX390, Predator 420cc Big Blocks

Long tube loop exhaust header for the Honda GX340, GX390, 420cc Predator, 460cc big block clone engine for mud motor boat application. Header pipe give your engine more low to mid range torque specifically for mud motor boats.

Our Price: $69.95
GX390 Big Block Bored Carburetor 23.5mm Venturi GX390 Big Block Bored Carburetor 23.5mm Venturi

Bullfrog Performance Products big block bored performance carburetor.  Our carburetor is CNC bored to obtain consistant max air flow.  Our carb has extensive carb air horn modifications along with the fuel circuits re-worked for the best transient and wide open throttle use.  Select if you need gas or methanol / alky fuel.

List Price: $171.35
Our Price: $149.00
Savings: $22.35
Forged Flat Top Piston Kit 90mm Bore, .900" Comp Height Forged Flat Top Piston Kit 90mm Bore, .900" Comp Height

Bullfrog Performance Products forged flat top piston kit for the Honda GX390 (block needs bored) LCT 414cc and 420cc engines.  This forged piston kit is a 90mm bore with .900" compression height.  Our piston fits our 4.650" length billet rod only.

List Price: $224.25
Our Price: $195.00
Sale Price: $175.50
Savings: $48.75
Forged Dome Piston Kit 90mm Bore, 1.100" Comp Height Forged Dome Piston Kit 90mm Bore, 1.100" Comp Height

Bullfrog Performance Products forged dome piston kit for the Predator 420cc engines.  This forged piston kit is a 90mm standard bore with a 1.100" compression height.  Our piston fits our 4.440" length billet rod or the ARC Racing connecting rods.

List Price: $224.25
Our Price: $195.00
Sale Price: $175.50
Savings: $48.75