They call for this on somewhat regular intervals. It's easy on this engine, so I pulled the valve cover this weekend. When the notch(2nd notch) on the main pulley lines up with a pointer on the block, it's Top Dead Center. This leaves free either; 1-2-3-5 valves(from the front) or, 8-7-6-4, on the next revolution. This is an older Japanese engine design, and quite simple.

After a good warmup running the engine to full heat, 7 of the gaps between push rod and the rocker had just a slight drag with a .014 feeler gauge. # 5 had a larger gap, enough that I adjusted it.

#5 is (I think) the exhaust valve for the #3 cylinder. I swung the pulley a couple more revolutions and rechecked all 8, all good.

I sounds great, maybe even better but that could be my optimistic nature.

Here's my question;

How wide do the clearances have to get before the performance of the engine becomes effected?