KTM RC390 Cylinder Head Stud /Nut Kit 2013/Present

Original price was: $139.99.Current price is: $129.99.

Stock studs are made from poor material that will stretch and allow gasket leakage. This kit is very high strength and can greatly help to prevent engine damage.

7 in stock

SKU: SP24-390 Categories: ,


KTM RC390 cylinder stud Kit are necessary to prevent head gasket leakage in high compression Race Engines. Stock studs are made from poor material that will stretch and allow gasket leakage at both the head and the base gasket areas. Spears Racing Cylinder head stud Kit are made from heat treated chrome moly, centerless ground, and have rolled threads after heat treat for maximum strength.
Spears Racing today is recognized as the industry’s leading manufacturer for Cylinder head stud Kit parts. We supply studs to all of the top engine builders

KTM RC390 cylinder stud Kit  “PRO MOD” STUDS
The RC390 engine uses head bolts instead of the preferred stud arrangement. When engines are subjected to bigger bores, higher compression ratios, etc. the stock head bolts are not up to the task. Blown head gaskets are the result.
These RC390  studs are made from ultra high heat treated premium chrome moly, centerless ground 8740 steel and feature rolled threads for maximum strength. When installing them into the case you should torque to 10/15Ft.Lbs. The new head torque will be 38/40 lbs. This set up is a must for all serious go-fast motors.

***A few words to the Purchaser, we would recommend you to assemble your engine as per the factory manual, once you have put the cylinders onto the engine cases at this time we find it simpler to install the Spears Racing RC390  cylinder head studs. Take the longer threaded end of the stud and apply moly or a light coat of oil and start the studs by hand into the holes(4) per cylinder  and make sure you torque to the proper specification (noted in the 10mm Stud Kit Install).


***Pictures of where the studs sit before drilling 10mm of threads out of the engine cases to allow them to have a lower install height.  The 2 holes that need to be drilled are without dowel pins on the cam chain side. You can see the studs are now sitting at the same level ***


Spears Racing has been designing and making race products for decades, their continuous committed to excellence to advance as the industry changes. This commitment has resulted in more components specific to certain applications, proprietary products only manufactured for us. Each of these aspects has been put through stringent research and development stages to ensure that our product will exceed your standards.


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