I would like more muscle from my Yanmar

[Dave]

I am a new to sailing and would appreciate some advice.I recently purchased an 1989 O'Day 322. The Yanmar 18HP engine did not handle the way I had hoped. With a moderate current and 15 knot head wind the boat inched along.I have a 2 blade prop and wonder if I should change. All advice is welcome!

 

[Steve Dion]

Need to have engine & prop specs.

Dave:Before you do anything, you need to know what you have as far as the engine/transmission/ prop.Take these to a prop shop and have them size a prop for your boat. Sometimes it is just a matter of tweaking what you have.

 

[Trevor]

More power under power

Hi Dave -I would highly recommend going to a 3 bladed prop. Keep your current 2 blade as a backup. You will accelerate much faster and attain higher top speeds when facing headwinds &/or chop. The downside is that you will be adding drag under sail. It's a trade-off. If you want to spend the money, go for a folding or feathering prop for the best of both worlds. As Steve said, you'll need to get more information to a prop shop to determine the correct size and pitch prop you'll need.Best,Trevor

 

[Allen Schweitzer]

PYI Props - HIGHLY Recommended

Dave,I'm guessing you have the yanmar 2GM20F. If so, you should check out the CDI composite prop (see related link below).It is specifically made for the 2GM20. I have one & it's fantastic. It's still a 2 blade so you don't get the drag of a 3 blade while sailing, but it has a variable pitch design that gives you a little more power than a regular 2 blade & it's better in reverse. I think a new one is under $300, so it won't break the bank.I have one on my Catalina 30 (LWL = 25', displacement = 10,500 lbs, beam = 10'11") and at 3k RPM's I get about 6 knots in flat calm water, but I still get decent headway in seas or a head wind.Anybody else have one of these? I'd be curious to know other people's opinions.Allen Schweitzers/v FalstaffC-30 Hull# 632

 

[Tom]

Actually the Autprop is probably best prop

for getting the most power out of an "underpowered" engine. It is a self pitching prop which would automatically adjust its pitch to the changing conditions. Works very well.I have heard of people with underpowered C36's (they have older 25HP engines) that put an autoprop on and got greatly enhanced performance. The only problem in your case might be that its a) expensive and b) might be a bit too big in the hub area to fit a smaller boat. Its really designed for larger boats, but it might fit yours.

 

[JPF]

Try a 3 blade MaxProp.

I had a similar problem with a 13 hp 2gm15 in my Seafarer 30. Just not enough engine for rough & windy conditions.I replaced my 2 blade fixed prop with a 3 blade"feathering" MaxProp. BIG difference.I gained about 15% forward speed in calm water and about 20% improvement punching through choppy water. Other benefits are less prop walk and much more thrust in reverse, as well as better light wind sailing performance.It was expensive, but next to new sails was probably the best upgrade I've made.