Hunter 33 2006 with Yan Y3M30 overheating

[hudjohnjen]

We bought our boat when it was 2 yrs. old and had the 3 blade Vari-Prop which was optional when it was new. I still have the 2 blade stock prop as a spare.

I get 6.5 knots at 2800 and will get over 7 - 7.5 at 3600 wide open.

Yes you should cruise at 80%, but occasionaly ramp up to wot for 10 min. to clear the carbon from the engine. ( from the Yanmar manual. )

The 3YM30 29 hp was part of the Mariner Package and was an upgrade from the base 3YM20 21 hp.

What is the diameter and pitch of the vari-prop which you have?

 

[Scott B]

What is the diameter and pitch of the vari-prop which you have?

Off hand I have no idea. I can check the manual I have on the boat this weekend and see if it's there, otherwise will be late Fall when we haul out before I can measure.

I do know the pitch is adjustable and is set when it is installed.

 

[Jim Beck]

This is a known problem with this engine. Unfortunately, Yanmar makes everyone have to figure it out themselves before resolving. I got mine fixed back in '07...Yanmar did cover parts AND labor.

 

[JohanB]

Yes - I ordered mine new with the engine upgrade at 30hp; the 19hp was the standard as you indicate. With a clean prop and bottom at 3000 rpm I average 6.25 knots. She doesn't get up to 7 knots at full tilt under power in flat water. But with a running swell she has gone over that. At max rpms she gets up to 6.85 knots. My most recent readings are faulty since my log sensor has gone bad. I need to replace it - any idea if that is difficult to do?

Johan