1 '85 K100 2V Exhaust Valves Light Gray Mon Feb 24, 2014 3:31 pm
diesputnikdie
active member
Got the cylinder head off last night to replace the cylinder head gasket and clean out the carbon when I noticed a heavy amount of white material on the exhaust valves. It didn't come off with solvent like the carbon did elsewhere, and it was as hard as a ceramic. As far as I know, the valve head should be smooth and reflective like stainless steel but it was on there so well that I just can't tell if it needs to be removed.
Should I grind this stuff off and recheck clearances? Do I need new valves? I see that the valves (#11 34 1 460 201) are in the $135USD range (For one? For a set? It's unclear) so an aftermarket part would be desirable. The problem is that the only info I can find in regards to the dimensions of the valve is a diameter of 30mm.
Thanks for the help!
Here's a pic before cleaning. Nasty!
And here's a pic after. You can see that the condition of the exhaust valve didn't change much, if at all:
Should I grind this stuff off and recheck clearances? Do I need new valves? I see that the valves (#11 34 1 460 201) are in the $135USD range (For one? For a set? It's unclear) so an aftermarket part would be desirable. The problem is that the only info I can find in regards to the dimensions of the valve is a diameter of 30mm.
Thanks for the help!
Here's a pic before cleaning. Nasty!
And here's a pic after. You can see that the condition of the exhaust valve didn't change much, if at all:
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1985 BMW K100RS (SN:0040831)