Jere Lull wrote:
In article ,
Moores family wrote:


I've just bought an H28 with an MD2B auxiliary. I haven't had a
chance to experiment yet but I'm looking for a starting point. I
know there's a bunch of people here with MD2B's in similar size
boats, what do you cruise at and what sort of consumption do you get
at cruise? Preliminary indication seems to be that 1600RPM in smooth
water is getting close to hull speed, so there seems to be a heap in
reserve. Interested in comments.


You may or may not have reserve. If you firewall the throttle and can
only pull 17-1800, you're probably overpropped and have little actual
reserve.

We don't have the MD2B, but the Yanmar 2GM20. We consume anywhere from
0.25 gph at about 5 knots and 2200 RPM to a bit over 1 GPH at 3200 and
hull speed of 6.6 knots. We can go faster (up to 7.2 at 3500), but not
long enough to get a good reading of the consumption. We tend to cruise
at about 1/3rd GPH at 5.5 +/-.


Thanks, Jere
I'm using less than 1/2 throttle to get to 'round 1500, so indications
are she's probably not overpropped. Is the Yanmar rated similar to the
MD2B- 25HP at 2500 RPM?
I'll continue happily experimenting...
JM