I have a 1987 etlh 70 hp Yamaha that I got used and had sat for a long time. I have disassembled carbs, cleaned, ultrasonic cleaned, recleaned and still can not get mid level acceleration smooth. Cranks good, idles good, runs 3/4 throttle up good. Have a set of 1989 Yamaha carbs off 70 hp engine available. Carb body part numbers same except for jets. Is it worth’s try to swap?