Prop for Yanmar 4JHE 44 HP

[Driftwoods]

This has probably been asked a million times but I can't seem to resolve it. I have a Yanmar 4JHE 44 HP with a Kanzaki Hurth transmission (boat is a 1987 Morgan 43). Documentation says is came with a 2 blade RH 17x12" propeller. Previous owner replaced it with a folding prop and I'd like to go to a 3 blade prop. Any idea on what size prop I should be looking for here?

[westwinds]

Why not go with the original propeller designed for the sailboat by the marine architect who put a lot of work into selecting it. On a three blade you can decrease the diameter by an inch and increase pitch by three (16 X 15), but you will have more drag under sail and less efficiency than a two blade and this 3 blade estimate is just a rule of thumb that is not very accurate, you might have to scrap it and get a slightly different one. There is a delicate balance between the size of the engine (thrust) and the length and shape of a sailboat hull (drag) and making changes can get you in trouble. There is an ebay listing for a 17 X 12 RH for $363. I would get two, one as a spare with a propeller puller to go with it if you plan on going off shore away from a ready source of parts.

[Driftwoods]

You mean do it the easy way? Never! ;-)

I understand a 3 blade propellor will give me a smoother ride under power and a little more control in tight spaces like my marina. I understand the trade off in extra drag under sail but the quarter to half knot loss may be worth it for the benefits. I will try to get that 2 blade though for the spare. :-D

[C4 King Cobra]

I replaced my prop with a 17/13 Michagan 3 blade on a 4jhte 55hp yanmar. The original was a 17/12. The prop guy suggested more getup in reverse with the change. I found him to be correct. Happy with my setup.

[rover88]

Have a look at the Canadian outfit Campbell Sailor at West by North Enterprises.

I ordered a replacement prop from them based on recommendations of some very satisfied friends. Filling out their order form was like an interrogation, so be ready with all the boat's specs if you decide to go with them.

I have been unable to get to the boatyard to install the CS prop , so my suggestion is only based only on recommendation of trusted sailors and the quick and comprehensive service I received.

[westwinds]

Originally Posted by C4 King Cobra

I replaced my prop with a 17/13 Michagan 3 blade on a 4jhte 55hp yanmar. The original was a 17/12. The prop guy suggested more getup in reverse with the change. I found him to be correct. Happy with my setup.

Was the 3 blade any smooter? The pitch was increased by a inch because three blades 'stirs the water more' than two so need to take a little bigger bite.

[Driftwoods]

So I did get a 3 blade prop - Campbell Sailer. Can't put it on though. The previous owner used 5200 or something similar to affix the prop it now and that thing ain't coming off without some serious (i.e. expensive) effort. The diver I hired declared defeat earlier today and told me I'd need to get the boat hauled out to get the old prop off and put the new one on. Great.

[TheOffice]

did he use a gear-puller or just yank it?

[Bash]

Originally Posted by Driftwoods

The previous owner used 5200 or something similar to affix the prop it now and that thing ain't coming off without some serious (i.e. expensive) effort.

Hard to believe the PO could be that stupid. More likely anti-seize. Did the diver have a prop puller? If not, your problem is the diver, not the prop.

[donradcliffe]

If the diver's prop puller weighs less than 10 pounds, get another diver.

[westwinds]

It really takes a heavy duty puller for a tapered shaft. Grease can be used in an automotive application like on rear brake drums for about 1950 and older cars. Probably did not use 5200 for the boat, just the nature of a tapered shaft to be tight. Can you see any 5200 on propeller and shaft? If 5200 was used, then heating I would think would help get it loose, but it would take a good size torch for that size propeller. Heating would help anyway.

[Driftwoods]

He did use a prop puller, no idea how big it was though. Diver told me there was a residue around what they could see that "appeared to be 5200" but he couldn't be sure. It looks like some kind of sealer or caulking was used. The PO was a bit of a do-it-yourselfer with some occasional questionable choices so it's not entirely out of the realm of possibility. Maybe I'll try another diver.

[westwinds]

Originally Posted by Driftwoods

He did use a prop puller, no idea how big it was though. Diver told me there was a residue around what they could see that "appeared to be 5200" but he couldn't be sure. It looks like some kind of sealer or caulking was used. The PO was a bit of a do-it-yourselfer with some occasional questionable choices so it's not entirely out of the realm of possibility. Maybe I'll try another diver.

Talk to the diver and see if the puller is sized for this propeller. Has he used it on other boats this size without problem. If so, better pull the boat. Do NOT use a slide hammer; it can damage the transmission. Get one of those infrared handheld thermometers so the propeller is not heated too much, about the temperature of boiling water? Need to check with a propeller manufacturer to see how hot it can go. It could be you would have to pull the rudder and disconnect or cut the propeller shaft at the transmission, then replace propeller shaft.