Engine Shudder

[Rob McClain]

I have a 27hp Yanmar 3GM30F diesel on my 2001 Hunter 340. Often when I shift the engine out of gear into neutral there is a pronounced shudder from the engine. This is not an everytime occurrence, but it is much more frequent that I would like. Other than this the engine performs great. Have any of you had a similar occurrence? Is this somewhat normal or is there something specific I can check?Thanks for any tips.Rob

 

[Pete]

Rob-I'm guessing that the idle is set to low. I had this problem on my boat and for what ever reason it seams to be a common problem. The mfg spec for idle is 850 rpm's. Reset the idle and I bet your shudder goes away! You may need to adjust you idle by ear after using the tach to get you in the right range,most tachs are not accurate (some by as much as 10% off)Try the link below, this site is full on good info about Yanmars and has a board for asking questions. Check in the service section and idle spec's (you may also want to check the archives here on HOW as this has been mentioned before and has some good info also ! Good Luck !

 

[Trevor - SailboatOwners.com]

Idle setting

Pete -I agree with the other Pete; you likely just need to increase the idle speed to avoid the problem. Many new boats need to have the idle increased to mitigate this common problem.Best of luck,Trevor