Motorcycle Repair: valve adjustment, camshaft lobes, inaccurate measurement

Question
Hi Mark, Hope you had a good holiday and happy new year!I received your info for the valve adjustment, thank you.But how do I tell which valve I'm adjusting? are the valves in sequence from left to right? do the inlet valves correspond to the exhaust valves? what do the numbers on the camshaft holders mean? also,am I suppose to feel resistance when I insert the feeler gauge? sorry to overwhelm you so much so soon. Thanks as always

Answer
Jack,

Cylinders and carbs are numbered 1-2-3-4, left to right when viewed as if sitting on the MC. Each cylinder has at least one intake and exhaust valve. Intake valves are on the carb side of the head, exhaust valves on the exhaust side. If there are two intake or exhaust valves (with rocker arms) per cylinder, use a separate feeler gauge and simutaneously measure the clearance of each valve to ensure accurate measure. This prevents rocker arms from flexing on one side.

You'll need the service manual to explain how to rotate the crankshaft and align timing marks for check multiple valve clearances. For example; ".....align the "T" mark on the compression stroke of the #1 cylinder to check intake valves on cylinders 1 & 4, and exhaust valves on cylinder 2. Rotate the crank around 180 degrees and align the "T" mark to check....."

Cam caps wear with camshaft lobes. The numbers on the camshaft caps are for returning the caps to their exact places upon reassembly.

You should feel resistance when inserting feelers gauges. No resistance means the camshafts are not positioned correctly or there is excessive valve clearance. You'll have to learn the correct "feel" or proper resistance. Too much resistance can depress the shim bucket (valve stem) and give inaccurate measurement and adjustment. You want to feel a light drag when pulling the feeler gauge. If the next size larger feeler (of about 0.0005") can be inserted easily, need more drag (reduce clearance).

Hope this helps.

Mark