Replace Valve Seals
Posted 28 May 2012 - 04:27 PM
Posted 28 May 2012 - 08:27 PM
Posted 29 May 2012 - 05:46 PM
Posted 29 May 2012 - 06:43 PM
Yep, you're right just did.
Posted 30 May 2012 - 04:51 AM
This my first time doing valve seals so any advice is greatly appreciated!
Posted 30 May 2012 - 06:01 AM
Posted 30 May 2012 - 06:48 AM
There could be two reasons for that. One would be that the keepers ("collets") are shearing and moving up on the stem, and the other is that the top of the valve stem is worn. In the latter case, the valve should be replaced.
Posted 30 May 2012 - 10:05 AM
If I do need to replace the valve, is there some way to determine if it is stainless or titanium? I bought the bike used and the bottom had been redone at some point before I got it.
Posted 30 May 2012 - 12:02 PM
Posted 30 May 2012 - 04:48 PM
Well I typed too soon, I went ahead and pulled the other valves and it appears that the one in the picture lost the tip of the stem. The other four have what looks almost like a shim on the end (but still part of the valve). So now I need to figure out if these are stainless or titanium.........
Posted 30 May 2012 - 05:58 PM
What's the reason for the concern?
Posted 31 May 2012 - 08:38 AM
Absolutely not. Unless you don't care how long it lasts (or whether your engine randomly explodes one day) the seat MUST BE refinished. The new valve is perfectly round, perfectly concentric, and at the perfect prescribed angle. The seat is something less than that. The better the seat is finished, the better the valve will seal, and the less wear will be required on either the valve or seat to match the two up. The accuracy and finish is of paramount importance with respect to the longevity of the valve.
NEVER lap a titanium valve, no matter who says what: http://www.wiseco.co...alveInstall.pdf
There's no real problem mixing SS and Ti valves in the same engine, even when you're mixing one set or other, like just the intakes versus all the intakes or all the exhausts. The one thing you have to be certain of is that the appropriate springs are used for the type of valve in place. Springs intended for Ti valves are apt to fail in controlling valve float at high RPM with the heavier stainless valves, and springs for SS valves would be too hard on the lighter Ti's. Since you're using OEM valves, replace all 5 springs with new OEM. Cheap insurance if there ever was some.
Posted 31 May 2012 - 10:44 AM