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Cylinder Head Dowel, Honda GX390 Cylinder Head Dowel, Honda GX390

Cylinder head dowel for Honda GX240, GX270, GX340 and GX390 engines.

Our Price: $3.25
Oil Drain Plug, Honda GX390 Oil Drain Plug, Honda GX390

Oil drain plug for Honda GX240, GX270, GX340 and GX390 engines.

Our Price: $3.95
Solid Side Cover Dowel Pin for Honda GX390 - Short Solid Side Cover Dowel Pin for Honda GX390 - Short

Solid side cover dowel pin fits Honda GX390 engines.  Short version when using the Bad Ass Minis 500cc cylinder blocks.  Sold per dowel pin

Our Price: $5.95
Solid Side Cover Dowel Pin for Honda GX390 - Std Length Solid Side Cover Dowel Pin for Honda GX390 - Std Length

Solid side cover dowel pin fits Honda GX390 engines. Standard length version.  Sold per dowel pin

Our Price: $5.95
Oil Fill Plug for Honda GX390, 460cc Big Block Oil Fill Plug for Honda GX390, 460cc Big Block

Oil fill plug fits Honda GX240, GX270, GX340, GX390, 440cc and 460cc big block engine.

Our Price: $6.00
Crankshaft Oil Seal for Honda GX390 Crankshaft Oil Seal for Honda GX390

Crankshaft oil seal fits Honda GX340, GX390, 420cc and 460cc engines.  Use this seal on both the PTO or Flywheel side.  Engine requires two per engine so order a quantity of two per engine.

Our Price: $6.25
Valve Lock Set, Split Locks GX390 Valve Lock Set, Split Locks GX390

Valve lock set for Bad Ass Minis GX390 stainless steel valves.

Our Price: $6.95
Bronze Valve Guide, 6.5mm Honda GX390 Bronze Valve Guide, 6.5mm Honda GX390

Bullfrog Performance Products bronze valve guide set will fit the Honda GX340, GX390 and many other big block clone engines with factory diameter valve stem size of 6.5mm. Our bronze valve guide will outperform in longevity and performance over the factory steel guide. Has closer to the same heat expansion rate as aluminum head for a more stabil valvetrain operation. These are sold per valve guide so order two for replacing guides in head intake and exhaust!

Our Price: $7.39
Air Filter, Angled 4" Long x 2 7/16" ID Air Filter, Angled 4" Long x 2 7/16" ID

Small engine racing air filter for use in many applications including go karts, mini bikes and many other off road applications.
Aftermarket air filter for the Predator 212cc, Honda GX390, Clone engines when using our air filter adapters with 2 7/16" OD. This air filter is an aftermarket version of the K&N cotton gauze design. Be sure not to forget our air filter oils and cleaners to keep your air filter performing at its best.

Our Price: $9.95
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.

Our Price: $10.00
Red Line Two Stroke Racing Oil Red Line Two Stroke Racing Oil

Red Line Oil’s popular two-stroke lubricants contain base oils which have the highest film strength and greatest affinity for hot metal. Because Red Line is a superior high temperature lubricant, it can be used at lower fuel to oil ratios, increasing power and providing excellent scuff protection and cleanliness. Where many two stroke oils are recommended to run at 32:1, many Red Line customers often mix their fuel at a leaner, 40:1. Red Line provides the lubricating qualities of castor oil, but provide exceptional cleanliness, with low carbon residue that dramatically reduces plug fouling and smoke. Red Line provides special protection for reformulated fuels. Dyno proven to make more power over longer periods of operating time. *Two Stroke Racing Oil* The ultimate in two-cycle performance - provides improved power and perfect cleanliness. Power improvements of 3-5% have been obtained in dyno tests. The high-temperature stability prevents deposits in even the hottest upper ring and piston crown areas. Suggested for use at 50:1, but can be used richer or leaner, up to 100:1 depending on the type of engine and its operating conditions. Provides unequalled protection in motorcycles and marine engines as a premix or injection oil.

Our Price: $11.95
Air Filter, 15 Degree Angled 6" Length x 2 7/16" ID Air Filter, 15 Degree Angled 6" Length x 2 7/16" ID

Performance air filter that fits Predator 212cc, Clone and Big Block applications with an air filter adapter with 2 7/16" diameter adapter.

Our Price: $12.95
Honda GX390 OEM Lifter Honda GX390 OEM Lifter

Honda GX340, GX390 OEM lifter (sold per lifter, order two for complete engine).

Our Price: $14.95
Side Cover Gasket, 10 Bolt 460cc Big Block Side Cover Gasket, 10 Bolt 460cc Big Block

10 bolt side cover gasket for the 440cc and 460cc 10 bolt side cover

Our Price: $14.95
Liqui Moly, Anti-Friction Engine Treatment Liqui Moly, Anti-Friction Engine Treatment

MoS2 Anti-Friction Engine Treatment ensures immediate friction and wear reduction, adds an extremely protective and pressure-resistant boundary layer with low friction and lubricates during cold starts to prevent damage from lack of oil. Contributes to lower fuel consumption, longer engine life and less noise. Specifically designed for older engine designs with or without a turbocharger.

Our Price: $14.95
Dual Valve Spring Kit for Honda GX390 65 lbs Dual Valve Spring Kit for Honda GX390 65 lbs

Bad Ass Minis 65 lb. dual valve spring kit for the Honda GX390  big block single cylinder racing engines.  We highly recommend our 65 lb. kit when using any cams with .300" lift and higher.

Our Price: $15.95
Connecting Rod Bolt Set, ARP Rod Bolt Kit for GX390 Billet Rods Connecting Rod Bolt Set, ARP Rod Bolt Kit for GX390 Billet Rods

Connecting rod bolt set for ARC Racing billet Honda GX390 connecting rods.

Our Price: $17.95
Valve Spring Kit, Single Honda GX390 35 lb. Valve Spring Kit, Single Honda GX390 35 lb.

Valve spring kit for Honda GX390.  This is a set of single wound valve springs rated at 35 lbs.

Our Price: $18.95
Main Bearing for Honda GX390, 420cc, 460cc Main Bearing for Honda GX390, 420cc, 460cc

Main bearing for Honda GX340, GX390, 420cc and 460cc engines.   Requires two per engine.  (These are sold individually one bearing).

Our Price: $19.00
Rod Bearing Set for Honda GX390 Billet Connecting Rods Rod Bearing Set for Honda GX390 Billet Connecting Rods

ARC Racing connecting rod bearing set for ARC Racing and Bad Ass Minis billet GX390 connecting rods.

Our Price: $23.00
96mm Head Gasket for Big Block Engine (No Oil Feed Hole) 96mm Head Gasket for Big Block Engine (No Oil Feed Hole)

Bad Ass Minis performance head gasket specifically designed for Bad Ass Minis big bore 95mm cylinder blocks. This head gasket fits 96mm bore big blocks and is Made In USA!. This head gasket has a 96mm bore and is .043" thick and does not have the oil feed hole made into gasket.

Our Price: $24.95
Liqui Moly, Ceratec Engine Treatment Liqui Moly, Ceratec Engine Treatment

High-tech anti-wear additive, suitable for most 4-stroke engines as well as manual transmissions and compressors. Reduces friction and wear thanks to a unique combination of ceramic compounds and chemical anti-wear agents. It will prevent direct metal-to-metal contact and reduce friction to increase engine life and reduce fuel consumption in gasoline and diesel engines.

Our Price: $29.95
40mm Stainless Steel Intake Valve for Honda GX390, 460cc Big Block 40mm Stainless Steel Intake Valve for Honda GX390, 460cc Big Block

Bad Ass Minis stainless steel intake valve fits Honda GX390, 460cc engines. 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: $31.99
33mm Stainless Steel Exhaust Valve for Honda GX390, 460cc Big Block 33mm Stainless Steel Exhaust Valve for Honda GX390, 460cc Big Block

Bad Ass Minis stainless steel exhaust valve fits Honda GX390, 460cc engines. 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: $31.99
Crankshaft, 69mm Stroke GX390 Crankshaft, 69mm Stroke GX390

69mm stroker crankshaft for big block 460cc engines. Can be used in Honda GX390, but you may have to mill your piston to fit the Honda GX390 block.

Our Price: $98.00
Billet Valve Cover, Honda GX390 Big Block w/Cooling Fins Billet Valve Cover, Honda GX390 Big Block w/Cooling Fins

Our billet valve cover for the big block engine features our unique integral cooling fins for additional valve spring chamber cooling. Our billet valve cover is the lightest cover on the market. You can throw away your stock valve cover gasket as our cover comes with an o-ring seal that promotes better clamping force and eliminates oil leaks. The other billet valve covers on the market do not have the machining time put into their valve cover to make them work as a bolt on piece. Our cover is taller than the factory valve cover so it will clear any roller rocker arm on the market. You will also receive our custom machined aluminum crankcase breather fittings.

Bullfrog Performance Products billet valve cover fits big block engines listed below:

  • Honda GX240
  • Honda GX270
  • Honda GX340
  • Honda GX390
  • Powerhorse 414cc
  • Vegas Carts 460cc
  • LCT 414cc
Our big block billet valve cover will only fit the wedge style head and it will not fit the hemi heads on Predator 420cc.

Our Price: $145.00
Billet Connecting Rod ARC Racing for Honda GX390 4.410" Billet Connecting Rod ARC Racing for Honda GX390 4.410"

ARC Racing billet connecting rod for Honda GX390 engines.  Includes rod bearings and rod bolts.

Our Price: $150.00
Billet Connecting Rod ARC Racing for Honda GX390 4.450" Billet Connecting Rod ARC Racing for Honda GX390 4.450"

ARC Racing billet connecting rod for the Honda GX390.  This rod is 4.450" center to center length and comes with rod bearings and rod bolts.

Our Price: $150.00