spare prop?

[Hydraulicjump]

Hauled the boat onto the trailer yesterday to check the prop and replace the zincs. A momentary lack of attention a few weeks back and I nicked the prop. It has a small fold (1 inch long by about 1/4") on the outside of one blade. Besides the noise of the collision, I knew I had dinged it since the boat has a bit more vibration at 3400+ rpms and above and my WOT rpm dropped from 4000 to 3900. Time for some prop repair I guess. Can't blame anyone but me, unfortunately.

But this begs a question, particularly for you remote cruisers: do you carry a spare prop and the puller to remove it with? Not an easy job, I am told, and obviously not one done anywhere but on the hard.

Jeff

 

[knotflying]

I do carry a spare prop. Very costly ($900) but convenient to have. I also carry a puller. I did have to use it once. The prop popped off easily. I imagine in shallow water one could do it.

 

[SGIDAVE]

Hello Jeff,

Sounds like this is a good time to get a NEW prop...get your dinged original FIXED and keep it as a spare.

Investing in a prop puller would be nice so you could do the prop changing yourself. WHICH Acme prop does the R27 take?

IF you want to tweak the performance, your "new" prop could be slightly more/less in pitch/dia/cup depending upon what you are after.

I have Acme #650 and #224 for my 21EC which is a separate story. Anyhow, the props are VERY different in terms of performance. The 224 yields less than "desired" WOT rpm's, but MUCH BETTER fuel economy, so I tend to stick with it and use the 650 as back up or high altitude prop...if I ever make it to Lake Mead for instance.

Let us know how you decide,

/david

 

[Hydraulicjump]

Thought I would update this for those thinking about a spare and how hard (or not) it is to change a prop.

Naturally, Kenny Marrs jinxed me by saying "easy to do. Take you ten minutes, tops." No, I am the master of discovering the farthest distance between two repair points. And always on a smoking hot day.

After hauling the boat yesterday I got out my two new purchases: a huge crescent wrench (2" span) and my 6 ton 8" 3-jaw gear puller on sale from Amazon for $25. After removing the prop zinc and then the cotter pin on the prop nut, I then spent the next fifteen minutes (already 5 behind the Kenny schedule) trying to loosen the nut (you jamb a 2x4 into the prop to hold it while you crank). Eventually with some forceful persuasion and even more persuasive adjectives describing the parentage of the prop, the nut broke loose. Then the gear puller failure. 8" is too long. I converted it to a two jaw puller, and got it to pull (and bend), but eventually you run into the rudder. No go.

Falling further behind the Kenny schedule, I ran off to the local auto parts store where they lent me a 6" 7 ton 3 jaw puller. With an "I'll show you" gleam in my eye I rushed back and installed that beast on the prop. Magic did not happen. I tightened the puller so tight I thought it was going to break. Finally, I tapped the prop with a hammer near the cutlass bearing and BLAM! It popped off. A few minutes to swap the shear key, put the new prop on, tighten the nut, reinstall the cotter pin and put on the prop zinc and done. Exactly 100 minutes. Ten times the Kenny schedule.

The old, slightly nicked prop will be refurbished and stored, along with my new 6" gear puller (they sold it to me), hopefully never to be used, but glad to know if I am in the middle of nowhere and mangle my prop I can, with plenty of time, replace it. I think I could even do this standing in chest deep water. The key here is not to mangle the prop....

Jeff

ps: is the reason that the rudder is offset to the starboard from the center of the shaft so that you can get the prop off or is there some hydrodynamic reason I am missing?

 

[knotflying]

Believe it or not, I saw a guy remove a prop off a Ranger Tug without a puller. It was a bronze device that screwed onto the shaft once the nut was removed. Then he slammed it with a large hammer and the prop popped off. It seemed a lot quicker and faster than the prop puller.