I have a Briggs 9L902 0284-E1 3.5 that smokes on startup. This past winter I replaced the intake valve seal with an OE one since usually smoking on startup only is caused by that. Valve does not have play in guide either. Still smokes on startup. When I initially pulled off the head, there was a little oil collected between the piston and head. Sitting on the cylinder wall closest to the deck obviously. Not alot. I just find it odd if it was a cylinder wear/out-of-round or ring issue, it would smoke constantly and have low compression. Engine has good compression from the feel of it, and will start first pull; which makes me kind of doubt I have a compression issue. And it doesn't smoke alot and not for long. 2 seconds tops. After that it does not smoke anymore and if I restart hot will not smoke. Only when it sits for a week. We've had the mower since new and the engine has been meticulously maintained with oil changes every fall and clean air filters its whole life. Any ideas? Thanks