Cylinder head dowel fits Honda GX340, GX390, 420cc, GX440 and 460cc big block clone engine.

Intake gasket for Honda GX340, GX390 and big block clone engines.

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

Insulator gasket for Honda GX390 engines.

Dipstick fits Honda GX240, GX270, GX340, GX390, GX440 and 460cc big block engines.

Solid side cover dowel pin fits Honda GX390 engines.  Order two per engine.

Foam air pre-filter for our Mikuni 38mm Super BN air filter.

Bullfrog Performance Products copper exhaust header gasket for Honda GX240, GX270, GX340, GX390, GX610, GX620 and GX690.  Will also fit Predator 420cc engines and many other big block clone engines.

Crankshaft oil seal fits Honda GX390 engines.  Our crankshaft oil seal is made from Viton material to withstand higher operating temperatures.  Use this seal on both the PTO or Flywheel side of the engine.  Engine requires two per engine so order a quantity of two per engine.

Electric starter block off plate fits Honda GX340, GX390, GX440 and 460cc big block clone engines.

ARP crankcase side cover bolt fits Honda GX340, GX390, 420cc, GX440 and 460cc big block clone engines.  Order a total of 7 bolts for Honda GX340 and GX390.  Order a total of 10 bolts for GX440 and 460cc big block clone engines.

Insulator with pulse fitting for Honda GX390 engines.

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

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 exhaust header flange is 1/4" thick and CNC machined for the DIY person who needs to custom make an exhaust system.

Bullfrog Performance Products header flange fits the Honda GX390 engines.  Great item for the DIY person who wants that custom header design.

ARP head bolt fits Honda GX340, GX390, GX440 and 460cc big block clone engines.  Order a total of 4 bolts for one engine.

Bullfrog Performance Products set of valve locks for one complete Honda GX390 engine that fits our billet aluminum Honda GX390 aftermarket valve spring retainers.

Bullfrog Performance Products magnetic oil drain plug for Honda GX390 and big block clones.  Billet aluminum drain plug includes the copper gasket.  Our plug is a nice upgrade to catch any signs of engine trouble by catching the magnetic particles that may be in your engine oil.

Outerwears air pre-filter for our 500-1100 performance air filter.

Outerwears air pre-filter for our Mikuni 38mm Super BN air filter.

This head gasket is a graphite head gasket and will fit the Honda GX390 engine with 88mm bore.

This head gasket will fit the Predator 420cc and many other 420cc big block clone engines.  It is a graphite constructed gasket that is .048" thick.

Multi Layer Steel head gasket that fits the Honda GX390 engine.  Gasket has 89mm bore.

Works with either gasoline or methanol fuels to increase horsepower and torque of modified engines.

This head gasket fits Honda GX390 88mm bore and is .010" thick.

Small engine racing air filter for use in many applications including go karts, mini bikes and many other off road applications.

Gasket set for Honda GX390 engines.

Factory cast aluminum connecting rod for Honda GX390 engine.