Part: Coarse and Fine Valve Lapping / Grinding Compound
Why You Need This: Valve Grinding Compound, also called Valve Lapping Compound, is used to lightly sand the contact surfaces of your either new or within service limit valves against the valve seats to get a perfect seal before reassembling your head on your Honda CB175 / CB350 / CB360 / CB450 / CB550 engine. Whether you choose to replace your valves with our new CB350 / CB360 valves, CB450 valves or your original ones were still looking great, every one is going to need to be lapped and measured to insure your valves are going to seat and wear in properly your freshly rebuilt head. Since it is impossible to see how well a valve and seat fit together after years of wear make sure to pick up some Prussian Blue to check the consistency of the face contact the two parts make. This is done pre-lapping to determine the initial state of the parts and post-lapping to see if the lapping process was successful.
Sold as two .75 fl oz tubes, one coarse and one fine grade. One set will do several valve jobs.
Installation Tip: If you are replacing your engine valves then they must be lapped to the old seats in the head. Apply a thin coat to the valve face and press it into the seat. Attach a short piece of fuel line to the end of the valve and an electric drill. Spin the drill at a low speed while lightly pressing in the center of the valve face. This will give you a more consistent and even lap than a valve lapping tool. Remove the valve and wipe both the valve face and seat clean of valve grinding compound then apply a thin even coat of Prussian Blue to the valve face and press into head to see the progress. Thin, spotty or incomplete contact means the valve seats will need additional lapping or cutting to bring back them back to true. Take this process slowly and check your progress often. If you are close switch to the fine grit compound.
NOTE: Check your valve guides to determine if they are within service limit before hand. If they are not replace them.
