38racing wrote:I'm guessing then that your references to tdc were based on flywheel magnet location and not actual piston location.
Negative. That's the weird part. I verified TDC while visually verifying TDC on the compression stroke. It was easy because I had taken the front apart and could clearly see into the cylinder with a flashlight. I further verified after taking the valve cover off by disconnecting the pushrods and eliminating the valves from the equation altogether. As a newby, I often feel more comfortable doing it that way. Still kept getting that weird behavior. I started thinking that maybe the behavior was coming from my gauge but I tried it on a known good engine and it worked perfectly. It remains a mystery. All I know is that once I replaced the flywheel key, it ran like a top.
But fret not...we may just be getting it back again. The owner reported to me that he used it for about 3 hours, two cuts, and when he was putting it away, it started to run rough on him...had trouble keeping RPMS up. You know dam well I'm going to check that flywheel key first this time.
It used a woodruff style, not the rectangular style that I've seen in other applications. I replaced it with the exact dimensioned one from an assortment kit I have but maybe the grade was different and it sheered again. Torque specs on the bolt call for 49 foot pounds and that's what I used. Does that seem like enough? The flywheel on my Toro with a briggs was 100 I think.