[Pcpk]

Hi All,

I recently purchased a 1979 ODay 30 with a folding prop and am currently in the process of refitting it back to (what I believe) it's original 2 blade prop and have a a few questions and looking for help/insights. They are:

1. The prop that has been stored on the boat (and I believe original) is a Michigan Sailor 16RH-9. Can any one confirm that this is or fits into the specs of the original prop?
2. When 'test-fitting" the prop yesterday the prop slid up the shaft to almost touching the strut and had a bit of play. I have heard that a bit of play in the prop is normal for this boat and wanted to confirm if this is the case and should the prop be so close to the strut?

Again, any insights/ODay expertise will be greatly appreciated. Cheers...PK

 

[deniseO30]

I think it's the OEM prop. the shaft may have been cut. the engine changed moved? You could put a drive saver between the coupling flanges to gain an inch or so. Prop should NOT be loose on the taper!

 

[Alex W]

The right prop depends more on the engine and transmission than the boat type. Do you have the original engine and transmission?

16RH-9 sounds about right for a Yanmar diesel with the most common transmission (2.65:1).

 

[Pcpk]

Yes it's a Yanmar 15 HP diesel mod # 2QM15. Not sure of transmission but can check engine next time I'm on board. Hope that helps

 

[deniseO30]

Nice engine! did you just buy the boat?

 

[Alex W]

Yes it's a Yanmar 15 HP diesel mod # 2QM15. Not sure of transmission but can check engine next time I'm on board. Hope that helps

On my 2GM20F the transmission gear ratio is written on the back (shaft side) of the transmission along with the oil type and quantity.

According to http://j30.us/files/2qm15_servicemanual.pdf it looks like your transmission ratio is 1:2.14. Top speed is 3000rpm. You'd have to use prop calculators to see if 16x9 is appropriate, but it sounds very close based on my limited experience.

 

[Pcpk]

OK all...appreciate all the insight/info and I think with all the help and some additional research I'm getting this narrowed down.

The prop is the OEM, so that's solved now only remaining problem is fitting. I went down to boat yesterday and after a little work I got the prop to sit securely on the taper. However, the prop is still flush with the strut (see pics). I like the possibility of installing a drive saver to gain an inch or so of clearance but was curious if this could also be solved with adjusting the engine alignment? I found an original handbook for the boat online and it mentioned that "engine shift" is a possibility. Does anyone have experience with this? Again your help is appreciated.

ps. Yes Denise, it's a new purchase and looking forward to sailing ASAP

 

[deniseO30]

OK all...appreciate all the insight/info and I think with all the help and some additional research I'm getting this narrowed down.

The prop is the OEM, so that's solved now only remaining problem is fitting. I went down to boat yesterday and after a little work I got the prop to sit securely on the taper. However, the prop is still flush with the strut (see pics). I like the possibility of installing a drive saver to gain an inch or so of clearance but was curious if this could also be solved with adjusting the engine alignment? I found an original handbook for the boat online and it mentioned that "engine shift" is a possibility. Does anyone have experience with this? Again your help is appreciated.

ps. Yes Denise, it's a new purchase and looking forward to sailing ASAP

My boat has the universal 5415 I'd guess your engine trans combination are shorter.

Looks familiar!

 

[JimsCAL]

You definitely need to get some clearance between the prop and the strut. What was the problem with the folder? Did it have enough clearance?

 

[Pcpk]

Nothing was wrong w/ folder has shorter ?collar? and fit on shaft with proper clearance etc. Boat was used to race by original owner but I'll be cruising and want to swap it out for better motoring/reversing.

 

[deniseO30]

I'd keep the folding prop. no one seems to have problems with them and nearly every sailboat in my club has them.. (except mine LOL)

Drive saver's aren't cheap, but would add a good inch between the flange coupling

 

[JimsCAL]

Many cruisers have folding or feathering props. Nothing wrong with sailing a bit faster. And the powering/reversing performance is pretty good as long as the prop is properly sized.