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Air Filter Adapter for Mikuni 38mm Super BN Carburetor Air Filter Adapter for Mikuni 38mm Super BN Carburetor

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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
Side Cover Gasket, 7 Bolt Side Cover Honda GX390, 420cc Big Block Side Cover Gasket, 7 Bolt Side Cover Honda GX390, 420cc Big Block

Honda GX390 side cover gasket.  Fits all 7 bolt GX390 engines and 7 bolt 420cc big block engines.

List Price: $10.29
Our Price: $8.95
Sale Price: $8.06
Savings: $2.23
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
Stock Connecting Rod for Honda GX390 Stock Connecting Rod for Honda GX390

Factory cast aluminum connecting rod for Honda GX390 engine.

List Price: $18.34
Our Price: $15.95
Sale Price: $14.36
Savings: $3.98
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 Intake Valve for Honda GX390, 35mm Head Stainless Steel Intake Valve for Honda GX390, 35mm Head

Bullfrog Performance Products stainless steel intake valve for Honda GX390 big block engines. This valve has 35mm head diameter which is stock size for the Honda GX390 engine. We do offer multi angle valve seat machining to get the most flow from this 35mm valve. We highly recommend this valve when using high lift aftermarket racing cams to prevent valvetrain failure.
This valve will give you the required valve spring installed height to get proper spring rate and coil bind clearance when using high lift aftermarket camshafts.

List Price: $25.88
Our Price: $22.50
Sale Price: $20.25
Savings: $5.63
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
Billet Intake Manifold 38mm Super BN Carburetor to Honda GX390 Billet Intake Manifold 38mm Super BN Carburetor to Honda GX390

Bullfrog Performance Products exclusive billet intake manifold adapts Mikuni 38mm Super BN carburetors to Honda GX390 big block engines.  Will also adapt the Mikuni 36mm and 38mm round slide carburetors when using our rubber mounting boot.  Our intake has multiple bolt patterns and incorporates our exclusive throttle mounting bracket with our intake design.

List Price: $66.70
Our Price: $58.00
Sale Price: $52.20
Savings: $14.50