Greeting all, I am repowering with a Yanmar 3GM30F. Though I have data to indicate which prop to use,I would like to request some real world answers. 1. I've heard I need to keep the RPM's up on the engine to prevent head gasket failure. 2. I don't want the boat overpowered at idle as a result of prop size. 3. I'm Assuming 3 blade prop but am intersted in others opinions and experience. Thanks
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Another overpowered 33!
I installed a 3GM30 in my 33. Installed a 3 blade Michigan prop. I can't remember the technical name for the blade configuration but it is a working type prop with "Mickey Mouse Ear" shaped blades. If I remember correctly, and this is dubious, I started with 14 by 12, and was a wee bit under-propped. Had it re-pitched to 14 by 13. Cruise at 2750 RPM is about 6 knots, topping at 6.9 to 7. Acceleration is surprising, and low power is goos to pull friends off of groundings (Hunter 33 as tugboat!) The boat WILL pull to port under power, you will feel vibration and shake through wheel under acceleration, and you will get a bit more prop walk to port when reversing. The power is worth it. You'll motor through anything.
I installed a 3GM30 in my 33. Installed a 3 blade Michigan prop. I can't remember the technical name for the blade configuration but it is a working type prop with "Mickey Mouse Ear" shaped blades. If I remember correctly, and this is dubious, I started with 14 by 12, and was a wee bit under-propped. Had it re-pitched to 14 by 13. Cruise at 2750 RPM is about 6 knots, topping at 6.9 to 7. Acceleration is surprising, and low power is goos to pull friends off of groundings (Hunter 33 as tugboat!) The boat WILL pull to port under power, you will feel vibration and shake through wheel under acceleration, and you will get a bit more prop walk to port when reversing. The power is worth it. You'll motor through anything.
check with Hunter
Call Hunter and ask there suggestions on prop size. If my memory is corrsct they recommend a 3 blade 15x13 or a 2 blade 16x12 (both 1 inch shaft)
Call Hunter and ask there suggestions on prop size. If my memory is corrsct they recommend a 3 blade 15x13 or a 2 blade 16x12 (both 1 inch shaft)
They don't even put the propper prop on new boats.
Pete: I do not think that Hunter even puts the propper prop on their new boats all the time. The best way to get the propper fit is to contact a prop shop. Let them calculate the best combination for your setup. They are then responsible for making things right.
Pete: I do not think that Hunter even puts the propper prop on their new boats all the time. The best way to get the propper fit is to contact a prop shop. Let them calculate the best combination for your setup. They are then responsible for making things right.
Prop shop is a good start BUT .....
They will get you close. There are too many variables. The rest is up to you. And the best way I could think of to see a blank stare over the phone would be to call Hunter for a prop recommendation on a non-standard installation!
They will get you close. There are too many variables. The rest is up to you. And the best way I could think of to see a blank stare over the phone would be to call Hunter for a prop recommendation on a non-standard installation!
Gee Wiz Sam... do you pull inland ?
Hey Sam, Next time Boatus tug comes along side and ask me "do you need a pull?" I'll just tell them, Hey, my best new friend Sam is on the way and he will get me off this reef...
Really, just kidding boutus, anyway, my 3 blade prop on my 2gm works great, have not yet sailed with it, so not sure of drag, but micky mouse ears sounds about right. It does run pretty well as far as under power goes. Backing up, no prop walk what so ever. Hum, hope it's not a sea anchor!
Hey Sam, Next time Boatus tug comes along side and ask me "do you need a pull?" I'll just tell them, Hey, my best new friend Sam is on the way and he will get me off this reef...
Really, just kidding boutus, anyway, my 3 blade prop on my 2gm works great, have not yet sailed with it, so not sure of drag, but micky mouse ears sounds about right. It does run pretty well as far as under power goes. Backing up, no prop walk what so ever. Hum, hope it's not a sea anchor!Thanks to all
Thank everyone. I certainly did the prop shop inquiries using the Michigan wheel model program. They recommended a 15X10 or a 14X12 configuration using a three blade prop. It's good to have empirical data though. Sam...I'll think I'll go with the 14X13 taking your advice since it's the exact same configuration.
Thank everyone. I certainly did the prop shop inquiries using the Michigan wheel model program. They recommended a 15X10 or a 14X12 configuration using a three blade prop. It's good to have empirical data though. Sam...I'll think I'll go with the 14X13 taking your advice since it's the exact same configuration.
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