18 hp Yanmar

[Bob]

I own a 1991 Hunter 28 which came equipped with an 18 hp Yanmar motor. I notice that when I back the boat out of the slip there is no high pitched whinning sound, but when I back over a prolonged period of time (more than 2 minutes) a high pitched sound occurs. There is good flow of water through the impeller and out of the side. What might cause this whinning sound? Is this some kind of engine warning? Or is it just reminding me that the engine is in reverse (like some heavy equipment when in reverse)?

 

[David]

Yanmar

Have you checked your transmission fluid level? Overfilled will cause this sound and cause damage.

 

[Steve Dion]

Follow directions when you check the level.

Bob:David makes a good point on the transmission. There have been several complaints about these trannies when they are overfilled. You should have a service manual and check it out.You could be building up excess pressure as you continue to back up. There is also a vent in the transmission cap. It is very tricky reading the level on the stick. This oil does not get very dirty so it barely shows at when full (or overfilled).

 

[nick]

dipstick

when you check tranmission level the dipstick should not be screwed in