Hunter 28.5 - Is 13 HP Yanmar Enough Power?

Nov 17, 2012
1
Hunter 28.5 Litttle Egg Harbor
I have been motoring my Hunter 28.5 with a Yanmar 16 HP Diesel. I have the opportunity to purchase a Hunter 28.5 with a 13 HP Yanmar Diesel, but I am concerned it may be under powered! I motor in and out of South New Jersey Inlets like Barnegat Inlet, Little Egg Harbor Inlet, Great Egg Harbor Inlet, and Absecon Inlet. Little Egg, Great Egg, and especially Barnegat Inlets can push and roll the boat. Can a 13 HP keep the boat safe and moving forward, or is it under powered? I also use the engine in open seas.
Walter
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
For starter, do you find your 16hp adequate and have enough power reserved to feel safe? Do you think you would be better off with a little more power than 16hp? IMO, I won't go lower than 16 or 18hp for a 28.5 .
My friend's 280 has a 9hp, grossly inadequate, whenever he meets heading sea & tide, he runs the risk of going backwards. If he could hold his position, its bonus.
I think a motor is more than just bring the boat in and out of marina/berth. At times it a margin of safety in bad weather.
 
Jan 30, 2010
21
Hunter 33 St. Joseph, Michigan
I have the Yanmar GM2 (13 h.p.) in my H-33 82. It handles what lake Michigan throws at it, but you still have to use common sense.
 

pamona

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May 13, 2013
6
Hunter 28.5 sidney, bc
I have the Yanmar GM2 (13 h.p.) in my H-33 82. It handles what lake Michigan throws at it, but you still have to use common sense.
The 13 hp on our 28.5 will push our boat to hull speed easily so with the heaviest currents we encounter this is plenty.
 
Aug 20, 2013
38
Hunter 306 Deale, MD
I thought the GM2 (should that be 2GM as in 2GM20?) puts out 16HP.

Anyhoo, at 2,800 RPM with no wind or currents and negligible waves I push our 2002 Hunter 306 to hull speed. And few are the days that she won't hit 6 knots under engine.

I'd suggest that as long as your hull isn't Barnacle Central and you take care of the engine you should be just fine in terms of getting out and back.

Now, personally, if the conditions are (or are threatening to be) such that the 16HP won't cut it then I won't go out.

Nico
 
Feb 14, 2012
24
Hunter 326 Seattle
I thought the GM2 (should that be 2GM as in 2GM20?) puts out 16HP. Anyhoo, at 2,800 RPM with no wind or currents and negligible waves I push our 2002 Hunter 306 to hull speed. And few are the days that she won't hit 6 knots under engine. I'd suggest that as long as your hull isn't Barnacle Central and you take care of the engine you should be just fine in terms of getting out and back. Now, personally, if the conditions are (or are threatening to be) such that the 16HP won't cut it then I won't go out. Nico
I've found that the 2GM20F on my 326 to be a bit anemic . . . But then again, I go out in some bad weather. With a steady 30 knot headwind and 4'-6' seas, she makes only 2.5 - 3.5 knots over ground, screaming along at 3,400 RPM.
 
Oct 6, 2007
1,023
Hunter H30 1982 Chicago IL
My '82 H30 has the Yanmar 2GM (13 HP) engine. At full throttle, 3400 rpm, on flat water, it hits 6 knots easily. Throw in 4 foot waves and a 30 knot head wind and it slows down to maybe 3 or 3.5 knots. Just fine for me so far on Lake Michigan. I do keep the bottom pretty clean.
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
I've found that the 2GM20F on my 326 to be a bit anemic . . . But then again, I go out in some bad weather. With a steady 30 knot headwind and 4'-6' seas, she makes only 2.5 - 3.5 knots over ground, screaming along at 3,400 RPM.
MrSteve, looks like we're in same boat, so to speak. Have you consider repowering to Yanmar 3YM30 ?
 
Feb 14, 2012
24
Hunter 326 Seattle
MrSteve, looks like we're in same boat, so to speak. Have you consider repowering to Yanmar 3YM30 ?
Actually, yes. Just this week I got a quote to repower with a 3YM30. The complete engine is $10k, and associated labor to modify the rear engine mounts, remove the 2GM, install the 3YM, and modify the engine hatch/steps was another $4k.

Seems a little steep, but it's a reputable shop that I've dealt with in the past and was very pleased with their work. Hmmmmm. Anyone want an extra 2GM20F with 660 hours on the clock? ;)
 
Oct 20, 2013
45
Hunter 335 Tampa, FL
We used to have a US30 (1981) with an old Volvo MD7A. We repowered with a more powerful 13hp vs 16hp setup back in 2006. Although the engine never gave us a problem, and was much easier to maintain, we never achieved the motoring hull speeds of the old engine. The new engine had a 3 blade prop vs the old 2 blade spinning in the opposite direction. We lost a full knot motoring... never what sure why, however in the confines of docks, it had much more controllable power and prop walk.... The new engine actually had a little too much power at cruising RPM for our hull and the boat always wanted to climb the bow wave....
 
Oct 20, 2013
45
Hunter 335 Tampa, FL
Actually, yes. Just this week I got a quote to repower with a 3YM30. The complete engine is $10k, and associated labor to modify the rear engine mounts, remove the 2GM, install the 3YM, and modify the engine hatch/steps was another $4k.

Seems a little steep, but it's a reputable shop that I've dealt with in the past and was very pleased with their work. Hmmmmm. Anyone want an extra 2GM20F with 660 hours on the clock? ;)
How much do you want for the engine? VERY interested!!!!!
 
Feb 14, 2012
24
Hunter 326 Seattle
How much do you want for the engine? VERY interested!!!!!
Well, I'm still thinking over the refit quote, and the engine currently has a worsening oil leak from the lower front area, near the sea water pump.

Since I've owned the boat over the past two years, she's been a very reliable, trouble free engine. On my most recent, month long trip into British Columbia's Desolation Sound last Sept, she performed wonderfully over the ~800 miles. But over the last 4 days of the trip, I noticed for the first time, a few spots of oil under the front part of the engine. As each day progressed, as did the leak - eventually ending up that she drips 1/3rd of a quart in 12 hours of motoring. I'm 99% sure the front gasket is giving out.

The quote I was given was $1,200 to service the engine: remove exhaust elbow, manifold, injection pump, water pump, crank pulley, alternator, replace the front cover gasket, oil, filter, coolant, gear oil, adjust valves, replace seals, o-rings and reinstall everything.

I wouldn't mind simply reconditioning the 2GM, but I really want quite bit more umph if I'm going to take 3-months to circumnavigate Vancouver island this summer. ~50% more horses and 50% more alternator would really help.

What do you think is a fair price for my 2GM20F?
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
MrSteve, I'm very keen to know how your repower to 3YM30 turns out. I'm considering going same route as the 2GM20F is, in my opinion, inadequate for a 326. My main concern with repowering is space. I don't want any changes made to the bulkhead and engine cover. Hope the 3YM30 fits right in and feels at home in the 326 engine compartment. Good luck and let us know how it turns out? Thanks. Happy New Year!! :) :) :)

PS: what kind of modification will be made to the engine cover?