1987 excel help

Ok any 1987 Yamaha 225 Excel guys out their that know anything about these motors? Mine might have 100 hrs on it but having problems with oil injection but to make a long story short that is deleteted for now. Block off plate, both oil level sensors set to full to trick computer and looped oil hoses for top carbs together, middle and bottom the same figuring that would equalize pressure if any rather than plugging individually? 50/1 mix ratio and it runs like crap! Idles fine but any throttle and chokes and coughs bad! So does it have to be re jetted now because of thicker viscosity? Any help would be appreciated!