Remind me. Valve adjust ok with spark plugs put?
 

About to put in an order. Tune up time. I want to change plugs. I remember a prob with carbon buildup messing with the process. Remind me?

You can adjust the valves with the spark-plugs "out" if that's what you're asking. Carbon build-up on the valves themselves will affect the settings.

adjust valves first, then remove/replace plugs

the thought is that removing the plugs and rotaing the motor increases the risk of a piece of crap falling into the valve seat and sticking - I advise plugs in for adjustment...then change plugs one at a time

others might have another take on it but I spend two days scared sheetless with an 80% leakdown on one cylider due to a chunk o crap after a compression test with all plugs out