Valves: To Check Or Not To Check

[Samaki]

I have read a lot of varying opinions on here and other sources about the need for valve clearance checks. Many believe that you should ride on and check valves only if there is a performance problem or you begin to hear ticking from the top end. The Gen II manual recommends checking the valves at 14,500 miles, which seems pretty often to me. On my previous bike, a VFR750, I checked the valves at 43,000, found everything good and rode on past 100,000 before selling the bike; no problems. I had every intention of doing the same with my Busa.

I just completed the first valve clearance check on my Gen II at 45,000 miles and found five exhaust valves to be below the minimum clearance. Intakes were all spot on. Recommended clearance for the exhaust valves is .007" - .011". Two of mine were as tight as .004". I know this check and adjustment is a real pain, but based on my findings I would recommend doing the valve clearance check, not necessarily at 14,500 miles, but at some point before you get too far past it. I am planning to check mine again around 75,000.

 

[WuzzaCBXRider]

What's most important about checking the clearance is to find a valve that's NOT ticking, one that's too tight. I agree though that IME, the factory intervals seem to be waay on the safety side vs the reality side. On my 37 year old CBX with 24 valves the interval is 8,000 miles as I recall and about every 20,000 miles I'll check them. Every time, only 2-3 are a tad loose and need to be re shimmed. At over 65,000 miles she still runs like a scalded ape. My Busa turned over 60,000 miles the other day and whenever I've had the valves checked, none were out of spec. Of course I'm not hammering on the rev limiter either but I do ride them...quickly.

 

[202mphbusa]

correct, too tight is not noisy