Valve Woes
Posted: Sat Aug 23, 2014 11:41 pm
(Back story, skip if you don't care)
So I managed to grab another fzr 600, for 300 bucks. Kid said it wouldn't run and the "shop" he took it to (provided the work slip) said the issue was unresolved. Not sure why & I don't care, the issues was ridiculously obvious. It had been dropped on the left side and cracked the stator housing, so was swapped with a yzf. So yes, I vulchered the bike. Brand new michilan pilots, full V&H exhaust, unbroken plastics. Got it home swapped the stator housing, she grumpily fired up in 100 degree weather... Valve shim time! Another plus was the carbs were spotless, with what measured out to be new emulsion tubes.
(Now for the bad)
Every single one of the intake valves had zero clearance
... Leak down test was terrible. 3 full days of shiming, measuring, riding, repeat, I've got all clearances @ .300. Yes I know that's way over, but I suspected a ton of carbon build up on the valves. I've not pulled the heads off to check, but leak down tests are getting better as well as shim numbers going back up to stay @ .300 clearance. I'll go back down as soon as I can get the last cylinder sorted.
(Now for the question)
Number 4 shims are not changing, they are stuck on 1.50 with .300 of clearance, horrible leak down test, & running no hotter than 200 degrees. The other 3 cylinders are sorting themselves with running time.
Is it possible that neglected clearances would cause a valve to float into a piston and bend it?
So I managed to grab another fzr 600, for 300 bucks. Kid said it wouldn't run and the "shop" he took it to (provided the work slip) said the issue was unresolved. Not sure why & I don't care, the issues was ridiculously obvious. It had been dropped on the left side and cracked the stator housing, so was swapped with a yzf. So yes, I vulchered the bike. Brand new michilan pilots, full V&H exhaust, unbroken plastics. Got it home swapped the stator housing, she grumpily fired up in 100 degree weather... Valve shim time! Another plus was the carbs were spotless, with what measured out to be new emulsion tubes.
(Now for the bad)
Every single one of the intake valves had zero clearance
... Leak down test was terrible. 3 full days of shiming, measuring, riding, repeat, I've got all clearances @ .300. Yes I know that's way over, but I suspected a ton of carbon build up on the valves. I've not pulled the heads off to check, but leak down tests are getting better as well as shim numbers going back up to stay @ .300 clearance. I'll go back down as soon as I can get the last cylinder sorted. (Now for the question)
Number 4 shims are not changing, they are stuck on 1.50 with .300 of clearance, horrible leak down test, & running no hotter than 200 degrees. The other 3 cylinders are sorting themselves with running time.
Is it possible that neglected clearances would cause a valve to float into a piston and bend it?