Fh680D bent push rod(s)
While mowing my lawn 3 weeks ago I heard a weird (pht pht) like running over a plastic bag - if you know that sound, then I had 1/2 power on the mower. I searched the internet and it sounded like it could be coil wires so I replaced both and it still had 1/2 power. I guess I should have checked the spark first. A friend came over removed the valve cover and expossed the 2 bent push rods. also the exhaust valve liner was pushed up and the oil seal was destroyed. I ordered a new head and parts from Jacks and installed them yesterday. Started the mower and did a test cut for about 1 minute ran well - I was pleased with my work-first time at doing motor work, then as I was putting the mower away there was a small pop like a very small backfire just before I shut it down. I thought that did not sound too good so I started it up again and -you guessed it only 1/2 power. When i opened up the valve cover my intake push rod was bent and the exhaust rod was out from under the rocker arm. I am not sure what caused this other than maybe I did not set the valve gap correctly. So my question is- When I set the gap at TDC at 0.006" do I set the intake at the same time as the exhaust so they are both the same when the crankshaft is at the same place or do I rotate the engine and set the exhaust when the intake is open.? I assume there is a time when both are closed and a time when only one is open and the other is closed. Is TDC a time when they both should be closed? Also I set the gap at 0.004" but I found that the gap should be 0.006"-would that make a difference?