Saturday, I brough the engine of my little chipper to a mechanic, to have a look at it and get an idea about the repair/replacement. He said the timing wasn't involved. The lifter rod got bent because the bolt holding the rocker unscrewed, the rocker shifted and the rod pushed sideway. "It's nothing !". He straightened gently the rod with a hammer and put it back in place. We found again the hard spot in the rotation like I did (leading me to the possible timing issue) but it disappeared. He drained the oil to see if there's something abnormal. "Oil's level way too low and oil too dirty". I have to disaggry with the last one, only brownish, far from the black I use to take out of my other engines. But beside that, nothing bad in the oil but 2 small strips of silicon rubber. "That should be good, put it back in place and try it at iddle only first".
So I went home, but before bolting the engine on the chipper, I opened the crankcase, as I was really worried by the disapearing hard spot and a sqwicky sound. Nice and clean inside, no metal shaving, just again some thin strips of silicon rubber from the case's etancheity but nothing about a hard spot. One central cameshaft for the both cylinders, good position. I thought of a chunk of wood against the flyweel for the hard spot, but nothing on this side either. Should be good, but I don't like the unanswered questions.
I closed the crankcase, filled it with oil. Good rotation, still sqwicky. I put it back on the chipper with the bare minimum to test it. The starter didn't want to work properly but eventually started the engine. Not at iddle but with a little throttle because it wanted to stall. I didn't bolt the exkaust can, so I saw the problem(s) : the good cylinder was blowing hard and hot, but the "bad" one's blow ( the one with the bent rod) was weak and cold. Then after a moment, the bad cylinder began to work, but erraticly, with a lot of misfires and flames rushing out loudly by the exhaust. After thoughts; that's consistent with the exhaust can becoming dark red hot on this side at the night fall, which I spoted during the last weeks. There's an issue here running since some times. Maybe not the timing, but certainly from the valves on this side.
And still sqwicky. Not good, as there's no roller bearing holding the crankshaft,
I can't run like that, it will die on me. I have to take it apart, but not much time or place to do it properly, so I'd better order a new engine.
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