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View Full Version : I now await the prognosis


Speedwagon
Sat Jan 29th, 2011, 09:20 PM
I finally got off my lazy ass, and took the head off my 750. The #4 piston intake cam journals were oil starved for some reason. So now the head sits with Jim@TFOG awaiting a prognosis on why, and if the head is ok.
Speedwagon
Thu Feb 10th, 2011, 09:05 PM
And... Jim says the head is trashed! As he put it "you could shave with one of the intake valves."

Lucky for me, there is a used head on ebay right now!
TinkerinWstuff
Thu Feb 10th, 2011, 09:14 PM
sure it was oil starved and not undergapped? zero clearance will prevent oil from lubricating the journal. You can have wear on metal parts submerged in an oil bath if there is insufficient clearance for oil. Once you wear through the hardened surface of the lobe, it's soft as peanut butter from there. If Jim said the valve faces were worn, then the stem would protrude further through the head and make the cam clearance too tight.
Speedwagon
Thu Feb 10th, 2011, 10:30 PM
Yes, that is what is seems to be, now that he inspected it. Initially, it just appeared oil starved.
TinkerinWstuff
Fri Feb 11th, 2011, 08:56 AM
Good luck. What bike is it anyway?
Speedwagon
Fri Feb 11th, 2011, 09:40 AM
'94 YZF 750