Kawasaki Ninja EX400 Oil Pump Relief Spring 2018/Current


Custom spring has been reset to produce greater pressure. The spring does not require specific shim just reuse the OEM washer with the clip as per manufacturer procedure


Kawasaki EX400 Oil pressure Relief Spring  As a leader in the commuter “small”  bike world Spears Racing has been servicing and building the Kawasaki Ninja EX250/EX300 and EX400 for track day riders and racers all over the world  for several years,in fact built several WSS300 engines for teams in 2015.

One thing that Spears Racing had noticed was the current engine had low oil pressure and we all understand the lack of oil capacity that the engine really has. Looking into the oil pressure of the OEM  Stock engine it was determined that there was a need to have a more appropriate oil relieve spring that could increase the pressure by simply changing the amount of  “spring Tension” it would take to create more pressure at the area’s in questioned.

The current oil pressure spring from the Factory Kawasaki would produce approximately  1.5kg /3.3lbs. of oil pressure at 4000 rpm again with the OEM Relief spring.

The new Spears Racing spring is able to raise the oil pressure from the OEM numbers to over 2 times greater than stock,achieving  3.8kgs/8.37lbs. of oil pressure at 4000 rpm with this new Custom spring.Taking the oil pressure to over 2 times the OEM numbers was a serious increase of pressure in the area’s needed to sustain full throttle high RPM’s for a greater amount of time,not to mention that the engine would last longer for the conditions it was now being used for.  The Spears Racing spring does not require specific shims you will just need to remove the current stock OEM cir clip,washer and you will remove the OEM Stock pressure spring and replace it with the New Spears Racing oil pump relief spring as per manufacturer procedure manual..

Spring is made of Carbon & Exotic steel that give a yellowish color.

Kawasaki EX400 Oil pressure Relief Spring


1 ea Spring


Transmission oil pan gasket

This Oil Pan Gasket for the 2018/2019 Kawasaki Ninja 400 is a special design and the Designing engineers ensure that the gasket is drawn with state-of-the-art software and manufactured with the best materials, utilizing the most current and efficient manufacturing processes. Have an 85% shape-recovering while maintaining strong torque retention – ideal gasket material for machined surfaces.The design of this gasket will allow you to use several times,and also work better than the Kawasaki OEM gasket that comes on the Motorcycle.

AFM is a chemically blown, compounded nitrile synthetic rubber bonded to an aluminum core with temperature resistance of over 2500°F. AFM material has an 85 percent recovery while maintaining strong torque retention. AFM does not require gasket sealers or re-tightening.but we always recommend that all bolts be properly torqued
This proprietary AFM (Aluminum Foamette Material) gaskets feature an aluminum core with a chemically blown, compounded nitrile synthetic rubber bonded to the outside.

AFM will not stick to the engine case making replacement quick and easy so you don’t have to scrape off leftover gasket material. The aluminum core gives the gasket strength for a superior seal and prevents the gasket from weeping or seeping oil.

Today’s lightweight motorcycle engines are producing more horsepower, higher cylinder pressures and extreme temperatures. Spears Racing is committed to provide innovative, quality gaskets while maximizing your engine’s performance and power.

Understand that the OEM Kawasaki Gasket is designed to use one time,(Graphite based design)

This Oil Pan Gasket Does not require gasket sealer

Made in the U.S.A.