60 hp Merc 4 stroke prop questions?

I have a 2005 60 h.p. 4 stroke Merc on an Alumacraft tiller 165 Navigator. Have had it into two different shops not including the initial setup. The pitch on prop is 13. The initial motor height was moved up two holes from original.The original was the second hole. This solved the problem of getting it up on plane with 3 people in the boat,which by the way is why I had them look at it in the first place, but when turning on plane, sometimes the prop would cavitate.After spending $100.00 to have this done I took it to the only other dealer to check it and he lowered it back to 2nd hole. (another $100.00) Now I am back to square one. This last dealer claimes it was too high and the prop is wrong. Everything I’ve read calls for a 13 degree prop and the 10+” prop I have on it. They said it should be a 15 degree or even 17 degree and maybe bigger prop. The first dealer was a Merc dealer known to screw things up. The second dealer is more reputable, but do not carry Merc.
I am lost now. Does anyone have the same boat and motor that might have some insight on this problem??

If you are cavitating in turns it sounds like the motor was too high. How are your RPM’s in regard to your recommended WOT range? I think you are probably running two low of pitch and maybe hitting the rev limiter on the motor. I would think a 15 pitch or 17 would be more suitable.

I have a Alumacraft Magnum with a 60 Johnson 4 Stroke and I am running a 17 pitch right now but I think a 15 pitch might be even better for my rig. I have ran a 19 pitch but it was a little much for my rig and I was just barely hitting the WOT range for motor.

Mag165, My rpm recommended is 5500. I was running 5200 at the low motor setting and 5500 with the higher motor setting, which was fine except for the cavitating. One dealer thought my tach may not be accurate.
My brother has same exact yr. boat and motor, but a 50hp instead of 60hp, and he has same diameter prop, with an 11 degree pitch with no problem. What do you think of possibly a 12 degree pitch same diameter, with motor set at the lower setting it is now? It seems the Merc uses a smaller diameter with less pitch, the more I get to talking to people. The recommendation of a steeper degree prop (15 and 17 degree ) seem to be coming from different brand motors? While the Merc guys are right around 11 / 12 / and 13 degree pitch and 10+ “(smaller) diameter props. Thanks, Murf

Your RPM’s sound good. Do you always test with 3 in the boat? Always putting the weight in the same position? This does make a difference. Also, you haven’t mentioned using a ‘whale tail’ or ‘Dolphin tail’.
This WILL make a big difference! I had a 50 merc on a skinny 17’alumacraft lunker, and the whale tail made all the difference in the world. And when you turn, that ‘tail’ helps peg that motor right and tight in the water. You’ll be amazed.
Much has been shared regarding the ‘tails’ and they are far cheaper than messing around buying different props and paying somebody to make adjustments and so forth. Maybe someone will chime in and share the results of using the ‘tails’ on props. If you haven’t tried one, trust me, you’ll want one, and you’ll never own another rig/motor with out one.

Flatfish, My testing is always with just myself in the boat. The problem I am having is getting on plane with 3 people in the boat. With just me it zips right up in no time, but two other average build guys, and it takes 1/4 to 1/2 mile to plane out.
I really don’t know what a whale or dolphin tail is to be honest with you. I’ll try to do a little search on that tomorrow. Just to mention though, this is the wider 16 1/2′ alumacraft navigator. I think its 92″, and was new to their lineup in 2005 or thereabouts. Much wider than there “normal width” boat around 80″. Maybe this has something to do with it. I’m sure its not helping plowing all that water.

6000 not 5500 will be your rpm max. The wider beam will cause the boat to have less draft. Boat will sit higher in the water.
Running a 16.5 Lund with 92″ beam, 60hp merc 4stroke sitting in the middle hole, 13p sst for one to three people, and a stock 12p aluminum if more people are riding.
Trolling motor and 2 batteries up front. No problem with this setup.

Have a look
http://www.wholesalemarine.com/c/120003/Hydrofoils.html?gclid=CKHkhPWruKACFQTyDAodLUzaUA
If that link doesn’t work just put outboard hydrofoils in your search browser

Do you have power trim and tilt? This dosen`t help your on plane time. But unless you are running a 4 blade prop most boats cavitate trimmed way up when turning hard unless they are trimmed down.

Had a 98 1660 Lund Pro V tiller, 50 hp Mariner 4 stroke, and experimented alot with props. Settled on a 12 pitch stainless (Vengenance I think). Motor was all the way down. I don’t know what your boat is rated at, but if mine had been a console, it would have been rated at 115 hp (but only 60 hp as a tiller) I think many tillers ratings that come in console also, are underpowered for the weight of the boat. Finally concluded that 12 pitch performance was the best I could do for the situation.

Tom P. Yes i have power trim . I use it a little to get up on plane, but almost always run it all the way down, or just a titch above all the way down.

Dave C, Mine is rated at 60 tiller , but the same boat with console is rated for 115 (same as the one you had). I agree that they seem to be underpowered. I rember trying an 11 pitch prop a few years ago and that would hit the rev limiter around 6100 or 6200 rpm while topping out. The 13 pitch I have now is around 5200 rpm topped out. So maybe the 12 pitch prop is the answer..I think that would put me at or around 5700 rpm and still get up on plane.

I have an 05 navigator with a 60 hp merc tiller. The best prop I have found is a 11.25 x 10p. This one is quick out of the hole and max RPM’s is 6000. I do get a lot of spray from the out board and I am thinking the motor may be mounted wrong. These are very heavy boats and I’m surprised with the sixty max hp on the tiller. Seems like a 75 or 90 would be ideal?? Side Note: the new merc flo torque prop does perform better than the standard merc prop. Nick..

This post is probably to late to help but here goes. I too have a 05 Nav with a 60 merc. I run a merc Vengence 48 855858 A 51 13P prop. The Merc is mounted in the middle hole (about 1 1/2 inch above transom) I also have a 8hp 4 stroke yamaha on the back. I had to add a SE sport 300 fin to help with lift. I am happy with the overall performace. Its the same old story, there is no substitute for more horse power.