Whats that click in my engine, No compression, Valve stuck open maybe. Options

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Yesterday just before getting home I heard a click from the engine then again. It wasn't steady, just every little bit I would hear it. I could feel that I lost power and it even stalled once at a stop light. Since I was only a couple block from home I just keep going.

I found that cylinder 3 could only produce 20 lbs of compression. A leak down test was 22% with most air coming out of the intake. For reference the other cylinders were 100 to 105 compression and the leak down was 18% to 20% with air noticed just in the oil filler hole. I don't know how accurate my testing tools are since they are cheap ones I got from amazon and harbor freight.

I took off of my valve cover for cylinders 3 and 4 and with cylinder 3 at TDC I have over 1/2 inch of play with both valves and the pushrods are of course way loose. I haven't removed the rockers to pull the pushrods out yet to see if they are bent. I will do that after I pulling the engine either tomorrow or this weekend.

How screwed am I? Thoughts on best and worse case?

Here's a video of my loose rocker Video of rockers

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52 sounds about right. My reading indicates that I should be running 50s at my altitude (~4300ft). Mine had 57.5s when I bought it and it backfired at idle and at 2500 RPMs. I went down to 50s and it was a bit worse. The idle mixture screws were turned out 10 & 11 turns on all cylinders. I was shocked at that since you're suppose to start at 2 turns out and work your way back in. That hasn't worked on mine. Mine barely runs at 2 turns out. Even with the 65s I'm at 5 turns out on each. I haven't gone further with these jets since I think the less turns out the better. I've checked the points on each screw and they are all very pointed. Maybe this Weber model is different that the others in the way its tuned. I've got 40 DNCF 101-250 4D. They were put on in 88 by the pervious owner.

Anyway back to my original issue.... I found my loss of power after rethreading the intake side of that rocker was the exhaust side blew out. The exhaust valve was not opening and all that heat was going back into the carb i guess. I did notice the carb was unusually hot after my test drive. I didn't think much about it at the time since I hadn't checked the carb temps after other rides to compare it to. I'm probably lucky it didn't start on fire.

I dropped the motor again yesterday and retreaded the exhaust side and put it back in the car. Today I started it up and let it idle for about 15 mins then took the valve cover off and checked the gaps. Looked good so I took it out for a 20 minute easy ride. Power was good and it ran great. Tomorrow I will give it a harder test then check the valve gaps again.

[DRPHIL914]

52 sounds about right. My reading indicates that I should be running 50s at my altitude (~4300ft). Mine had 57.5s when I bought it and it backfired at idle and at 2500 RPMs. I went down to 50s and it was a bit worse. The idle mixture screws were turned out 10 & 11 turns on all cylinders. I was shocked at that since you're suppose to start at 2 turns out and work your way back in. That hasn't worked on mine. Mine barely runs at 2 turns out. Even with the 65s I'm at 5 turns out on each. I haven't gone further with these jets since I think the less turns out the better. I've checked the points on each screw and they are all very pointed. Maybe this Weber model is different that the others in the way its tuned. I've got 40 DNCF 101-250 4D. They were put on in 88 by the pervious owner.

Anyway back to my original issue.... I found my loss of power after rethreading the intake side of that rocker was the exhaust side blew out. The exhaust valve was not opening and all that heat was going back into the carb i guess. I did notice the carb was unusually hot after my test drive. I didn't think much about it at the time since I hadn't checked the carb temps after other rides to compare it to. I'm probably lucky it didn't start on fire.

I dropped the motor again yesterday and retreaded the exhaust side and put it back in the car. Today I started it up and let it idle for about 15 mins then took the valve cover off and checked the gaps. Looked good so I took it out for a 20 minute easy ride. Power was good and it ran great. Tomorrow I will give it a harder test then check the valve gaps again.

wow well im glad it was not a dropped valve seat, but with 2 of these having issues you might consider re-doing all of them, that just should not happen coming loose or breaking like that, but it sounds like you are getting good at dropping and reinstalling that motor!