TOPIC: 1968 125hp

So I bought this 125 from tim c. it starts like a dream has great exceleration but when you get to the last inch of throttle movement it loses its umph. it is not over propped at all. I took it out to tims and we ran it for a bit and he says the carbs were not synced right. we went back to the shop and he straitened out the problem.I put it back into the water and I am having the same problem. If you keep it in the throttle range where it happens every little bit it will sorta pop like its getting the fuel it is missing. I have two new tanks and lines ect and it does it with both of them. Does anyone have any thoughts on this?

It could be misfiring or cross firing. See if you can see any arcing running in the dark. Look for evidence of arcing to the throttle lever where it passes the plug wires.