valve stem oil seal failure (b12)

[370steve]

Question for the great unwashed out in engine god land??

are there any faults that i should look for as to why my engine eats valve stem oil seals!!

when i first rebuilt the engine it was burning oil (OEM Suzuki), so i had the over bore done and among other things i changed all the stem seals. (not OEM Suzuki)

not long after that it started to smoke again, as i had to take the head off for other reasons i changed them back to standard OEM Suzuki.

towards the end of the summer she started to smoke again at start up, now i have the exhaust and carbs off i checked into the ports, all exhaust valves are dry, but from what i can see, at least four of the inlet valves are wet!!!

head will be coming off again to replace them, is there anything specific i should be looking at? or am i damaging them whilst assembling to valves?

all tips/ideas welcome

[Gixer1460]

Quote

 

Query - absolutely stock head or have the valve guides been replaced? If the latter, they maybe to high and are getting clouted by the spring retainer - likewise if using a Higher lift cam - same effect. Not much else unless the guides are badly worn so valve stem is knocking them out? Lots of oil / assembly lube whilst fitting them - difficult to damage really unless seating them with a mallet!

[370steve]

As far as i am aware it was a stock head when i got the motor, i have fitted GSXR1100 cams. guides dont seem to be worn (engine had a claimed 18k)

[colinworth79]

If you have a gen suzuki manual has a bit in there how to check guide wear. Sounds like the guides are worn past the service limit. 

[jonny1bump]

It's certainly worth checking your valve lift and make sure they not bottoming out as Ian has said.

Also check for roughness on the valve may have picked up. 

Other then completely as stated above worn guides but to go that quick suspicious of bottoming out or some sort valve issue.