No power, process of elimination?

1974 cb450. Engine starts easily and runs smooth at idle. Blipping the throttle sounds normal too. Spark is good, carbs have been meticulously cleaned, floats set.
It just won't accelerate under load. Just bogs down. Found out the compression on both cylinders is at 120 (well aware 160 is probably the lowest the engine will tolerate). Also, can't line up the timing marks on the cam when at TDC. Guessing the PO put the chain on incorrectly.
I'm currently building another engine, but can I assume that was the root cause of the bogging down/lack of power?

Have you checked the valve clearances?

VonYinzer said:

Have you checked the valve clearances?

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I haven't. I was chasing my tail with this engine so I figured I'd just spend the time (and money) on the original engine which has 7K and hasn't been molested. I'll be sure to check all the clearances on the engine I'm rebuilding. For the sake of learning, what's the theory behind the relationship of clearance/lack of power?

Compression = power. If the valves dont close and seat properly, your motor cant make good compression. That problem is exaserbated when the engine is under load (i.e. riding up a hill).

Check to see if all 4 cylinders are firing.