115 yamaha 115 rough idle in gear

[tim costin]

I have a 17' runabout that I use for lake and ocean here on Vancouver Island.I bought the boat 3yrs ago.When I first used the boat, the motor would cough and die.I took it to the dealer and he cleaned the carbs.This cured the hesitation when opening the throttle(I waterski).The problem I still have is that the motor runs poorly in gear above idle.Once I am up to 2000rpm it runs fine.The dealer said the motor runs this way because it is sitting too low on the transom.He showed me the cavitation plate being slightly below the bottom of the boat.He said the motor needs to be moved up two holes as there is too much spray coming off the motor(they water tested it).This would be about 1".I realize that it is a 2 stroke and will never run as smoothly as a four.Any suggestions?

 

[yamamarinetech40]

Re: 115 yamaha 115 rough idle in gear

Find another dealer....there is absolutely no connection with mounting location and performance between 1000-1500 RPM...does sound like it needs to come up IF there is a lot of spray being generated from midsection....you say you bought the boat three yrs. ago and already dirty carbs..so used, right? What year is motor? Why did dealer give it back to you less than perfect and why did you accept it? Probably still carbs....hard to tell