Honda 120 Quarter midget Intake Valve Spring Shim .030 thick KBP1104

KBP1104 - Honda 120 Quarter midget Intake Valve Spring Shim .030 thick  1pc

This is a Honda 120 only part. The quarter midget rules state you must remove the valve seal. This valve seal retainer sits under the valve spring adding height to the spring giving you slightly more intake spring pressure, that we all want. But the rules also state that you are allowed to add a .030" shim under the spring. This is that shim they are talking about.

This intake shim gives you slightly more spring pressure than the guy that is not using it. Many people do not even know that it is in there and while replacing valve springs it sticks to the bottom of the spring and is often removed and tossed in the trash with the spring or your builder never put this advantage in the engine.

Now you can add it back in or if it was never there gain some performance by adding it. If you can change valve springs, you can do this modification. Pop the valve spring out, put the shim under it and install the new valve spring.

Tech Tip: you want the intake to be snappy and the exhaust to be lazy so when replacing valve springs always replace the intake spring and move the intake spring over to the exhaust side and discard the old exhaust spring. This is a great routine for the best engine performance - and don't forget to use the 140 valve springs.