repowering a 1978 hunter 30

[flhunterowner]

Has anyone here repowered/replaced their YSE12 in a 78 era hunter 30?
I replaced the oil pump in mine and my oil pressure seemed great on the bench and at the dock. The oil pressure even increased when throttling up.

We ventured out this weekend and the oil pressure would drop to 20psi (from about 60 psi) 1/4-1/2 throttle. At 3/4 throttle the engine would start to get hot and make noises.

We were lucky to get 2 mph from the engine and if we had to fight wind and tides, well forget it.. I was just burning fuel.

How do you connect a tach to this engine? I have no idea what the engine was actually doing.

whant should I expect from this engine and what would be a suitable replacement?

What is the REAL speed of these boats and engines? I can handle slow motoring, but <2mph..geez.

thanks all.

 

[Ian McGain]

As I have a 1979 Hunter 30' with a Yamar YSM12, I can only speak to your last question. At 25000 rpm, with a clean bottom and a clean prop, you should be able to motor 4 1/2 to 5 knots. Use a GPS to read your speed over water. I have had my prop fouled and found the boat would not move, even at full throtle. My Yamar came with tach, but could not tell you how to attach. I would think this is a part you could order.

You oil readings speak to larger problems, that may refer to hours on your engine. It reads as if there are some serious issues here I can not comment on

On replacement- bigger is better.

good luck
Ian
s/v Meant to Be

 

[graham]

We have a rebuilt 18 hp Yanmar 2GM15. We tend to motor at 2000-2200 RPM and no overheating happens. 2500 seems to be pushing it. GPS reports a little better than 5 knots (I haven't a working knotmeter atm).

I should think you'd be able to to make 80% of theoretical hull speed (or your top sailing speed) without pushing too hard.

If this engine needed replacing (it was rebuilt by the last owner) I'd be looking at an electric drive. All that spare battery power for the fridge ;-)