Quote Originally Posted by not2fast View Post

Quote Originally Posted by d00m View Post
Someone locally told me that the chains get killed cause of the oil pump/tensioner issues. From what he said at a certain time during use the oil pump will lose pressure to 0 this makes the timing chain tensioner lose tension for a split second then regaining tension when oil pressure is built up again thus shocking the chain from re-tensioning this shock is what kills the chains, from what he said. Doesnt the SHO and SVHO have two different oiling systems?... Also when i went to my local dealer the service writer told me yamaha has them doing a mod to the oil pump so this doesn't occur, which hasn't really helped. Can anyone confirm this?
So is this really the issue?
Nope - likely NOT at all.

My memory is a bit fuzzy ... but the 1.8L ACCT has a built-in one-way ratchet-like mechanism (aka there's a "reset" technique in the shop manual), so it simply does not "give back" any slack at any time during its service-life.
If it takes up all the available slack (resulting in a very tight chain condition), the only way things will somewhat loosen again is if the chain stretches, period - - - or a mechanic "resets" it.
IMHO, THAT simply doesn't sit right with my mindset - so even though I don't have a SVHO, I still swapped mine out for a MCCT.