Prop size/Yanmar 2GMF

Oct 30, 2019
1,021
Hello: Calimera, V1071, was repowered in 1983 with a Yanmar 2GMF (15 hp).
The propellor supplied at that time was a Michigan Sailor, 3 blade, 15 diam x
10 pitch. I'm planning to go to a 14 diam so that the engine will reach
recommended 3400 rpm rather than the 2800 or so that it maxes at now. What
props to others have with this engine? I'm hoping to have a prop shop cut
this one down and possibly modify the pitch as well.

Fyi, I'm happy with the Yanmar 2 cyl. Very smooth and reliable. I keep
upgrading parts of the installation that weren't done as well as they could
have been. I've just added a PSS dripless shaft seal and will let you all
know how that works out. I saved the old stuffing box just in case.
Beautiful machining on the PSS seal, and a nice fit to the existing stern
tube. Bill Bach
 
May 9, 2011
1,000
Hi Bill. What kind of fuel consumption have you been getting? I repowered
Lyric in 1998 with a 2GM20F. Prop size was 12 X 9 RH. We ran it at 2600
hundred rpm as anything higher was wasted. At 3200 rpm she would squat her
stern and make a wake you could just about surf on. We re-pitched to 12 X 8
RH the next year and found we could get up to 3200 or so but with no
discernable difference between 2800 and 3200. I have noted a problem with
soot around the transom exhaust which indicates unburned fuel (or so I am
told). Hull speed is around six knots. In all fairness though, Lyric is a
heavy boat. We are definitly down on our lines as we've added such things as
a propane system and stove, fridge, watermaker, windlass, 200ft of 1/4" Hi
test chain, bruce, 4 golf cart batteries, solar panels and all the other
goodies my other half could bring home from her job at West Marine to make
our cruising comfortable.
Slow, but comfortable. We certainly are not a fast boat but I have no doubt
that we are the best equiped Vega. Walt Brown
P.S. We also found the engine to be loud and with its width we have little
space for insulation.
 
May 9, 2011
1,000
Hello
Bill:

How is
the refit going? Are you able to make it up on the July weekend? I hope the
e-quake did'nt cause any damage out your way. We swayed a little here. I thought
I was having a dizzy spell. Must be my age.

Cheers

Brian
- 1039
 
May 9, 2011
1,000
For my Beta 13.5hp, I happened to find an old 13x9 in good condition for $75 which seems to be
perfect. Though I don't have a tach., it will push "Windhover" to 7.1kt
under calm conditions and gives less than a quart an hour fuel economy at
cruising speed.

As to whether to repower, I would not have if I my
Vega were diesel powered. I bought her as a fixer-upper and could see that
someone had had some problems with it O-21, had tried to install an electric
fuel pump. Not being very mechanical and envisioning an easy $500 in
repairs to the O-22(there is an article is the Vega Handbook which says a
replacement dynastart is $900). I decided to repower, given the special
that VAGB was running, and the belief that I would have "Windhover" for the long
term future.

With regard to shaft seal, a much more economical
altertnative is a conventional 1" perko stuffing box with "Drip-free"
packing. I do not get any drippage at cruising speed though I do at full
throttle @7.1kt.

Steve Wallace
 
May 9, 2011
1,000
Walt: Thanks for the info on prop size. My fuel consumption is very good,
less than a quart per hour at 2000 rpm. I'm waiting for a prop analysis from
Michigan Wheel to see what they recommend. Bill