Leaderboard

Despite report from your tech, I suspect timing. Recent work on three Bears of that era, the cam guides/chain do seem to experience some slack, and wear. Jumping time is easy on one with some miles, but there may still be enough slack that one might visually mistakenly believe the marks are accurate. I fear just tossing external parts at it will get expensive, not to mention possibly futile. May be time to do head/rings/chain and guides-it's gonna be more expensive, but the long term benefits will keep giving return in power and fuel consumption. Are the guides worn down badly? Adjuster working correctly? I am assuming he has pulled the left sidecover off and pulled flywheel/starter clutch to see chain and lower sprocket, guide bottoms, adjuster? What did compression check yield?

When the chain gets worn, it will often knick the case on the left side under the sidecover, below the timing chain front lower guide. If you see any scrapes there-or a broken aluminum case edge, pretty good bet you found problem. One that has a stretched chain/worn chain glides/malfunctioning adjuster will often run, but have a strange "slapping" sound, particularly at lower revs (where you can actually hear it above the normal engine sound). It will often be very pronounced while fast-cranking (boosting) or with spark plug out, and sounds like a sliding/slapping, not really a knock as such. That's the chain brushing against the case as it spins. I have removed plugs, and completely backed out the valve adjustments, for diagnosis. It relieves the cam from spring pressure, allows starter to spin faster, which accentuates the "slapping chain" noise scraping on the case, as compared to normal cranking with valves adjusted to spec/spark plug in. Hope that helps

Sounds like a timing issue or possible a faulty CDI. Before that, I would start checking all wiring. When you say speedometer odometer, is it digital and not working or is it an analog display? Do you have a speed sensor?