2002 Crestliner 1750 & Merc 150 4S Prop?

[bersh]

Great - another prop question. Long story short, last fall I purchased a Mercury 150 4 stroke to put on my 2002 Crestliner 1750. Turns out my transom was shot, so I rebuilt it and finally got the boat in the water a few weeks ago (separate thread on the transom rebuild will be coming soon).


We recently purchased a camp on the lake, so the boat is now in the water until fall. The boat is primarily used for fishing and tooling around the lake, but I also use it to pull my 12 year old and his buddies on a tube(s). I've never been a water skier, but chances are good we'll be messing around with that and other watersports as well.



The motor is mounted on the 3rd hole, AV plate is about 1.5" above the bottom of the keel. The motor came with a new 18P Black Diamond prop, which I have been using for now, but it's obvious it's not quite the right prop for the boat. With that prop, the boat jumps on plane, and it runs about 5500-5600 RPM and about 48 mph (GPS) trimmed as much as I can without blowing out. I'm actually not displeased with the way it runs or the numbers, but the problem is it blows out very easily in turns, especially when pulling the tube, and I can hardly trim the motor at all. I suppose I could drop the motor a hole, but I'd rather try to leave it where it's at for now and only drop it if I have to.



My local dealer has offered to do some water testing to figure out what I need. The problem is that they have very few props in stock, and aren't willing to order a bunch just for me to try and then only buy one. They did, however, have a like new Vengeance 19P they had pulled off another boat laying around that they're willing to let go for a great deal. I took the prop home to try for a few days, and it is better than the aluminum that came with the motor, but not a night and day type difference. It runs about 5400 rpm, just shy of 50 mph, still jumps on plane quickly, and doesn't seem to want to blow out as easily. I haven't had a chance to try pulling the tube with it yet. For the price, considering that it grabs the water better than the aluminum, I'll probably buy it. I still don't feel like it's quite the right prop though.


So, where do I go from here? Temped to try a Nemesis, but not sure on the pitch. If that pans out I'd be willing to jump to a stainless 4 blade, but not sure if I should stick with Mercury or explore one of the off-brands to save a few bucks.


Thanks.

[Cobbled]

I have the same boat as you. There is nothing wrong with a non mercury prop. I have a ss 19p apollo prop on mine and it still uses the merc Flo torque hub. Different motor tho. What were the symptoms your transom was bad? I'm pretty sure mine is good just wondering.

[bersh]

Originally Posted by Cobbled

I have the same boat as you. There is nothing wrong with a non mercury prop. I have a ss 19p apollo prop on mine and it still uses the merc Flo torque hub. Different motor tho. What were the symptoms your transom was bad? I'm pretty sure mine is good just wondering.

In retrospect, I had noticed that the top cap was loose, and the motor mounting bolts were really loose when the old motor was removed. In addition, I once tried to tighten one of the top cap screws that had backed out, and it really didn't seem to grab any wood.


The final indication was when the new motor was mounted, they couldn't torque the motor mounting screws properly (or at all), as the inner and outer skin just kept squeezing together.

[bersh]

I'm mulling a Solas Rubex HR4 - anyone have any input? Any other off brands I should be looking at, or avoiding?


I'm tempted to try a 17p and 19p 4 blade with the hopes of finding one that will provide the best overall performance so I can avoid having $1000 in props laying around and swapping them out all the time.

[bersh]

I ended up finding a good deal on a Solas 4 blade 19p on ebay so I bought it. Worst case I can try it and sell it if it doesn't work out.

[TomP.]

Had sort of the same issue as you Crestliner 182 135 Optimax running a 19 pitch talked to a prop rebuilder and he said to add cupping so I let him do it. Made an extreme difference in not blowing out in tight turns trimmed up.

[bersh]

I tried out the Solas 19P last night. Close, but not quite right. Jumps out of the hole good, but I think the Vengeance 19p is better. Had a bit of chop so top speed run will need to be rerun, but only turning about 5200 and 48 mph. It does seem to get and stay on plane a little easier and lower rpm.speed. The biggest thing is it grabs the water much better. I could still blow it out if I really cranked the wheel, but I had to work at it.

This weekend will be the test as I'll be pulling some kids on the tube.

I'm probably going to order a 17p to try, so chances are good there will be a like new Solas 4 blade prop for sale in the near future.

[bersh]

Finally got around to testing the Solas 17p, and I like the 19p better. Given everything going on right now, I doubt I'll have a chance to tow the kids on the tube before I pull everything (early end to the season due to shoulder surgery). I lost a considerable amount of top end, it seemed to blow out a bit easier, and cruising speeds at various rpms were considerably less than the 19p. I did gain a couple hundred rpm on the top end, but it's useless as I lost 8 mph. I'm pretty shocked, actually.


Guess I'm still shopping.

[2catch1]

This is odd to me. I have a 194 princecraft ventura deckboat with the same motor and get 46-47 mph with a 3 blade 19p merc aluminum prop mounted on the lowest hole running 5600-5800 rpms. I guarantee you my boat is a fat pig compared to yours. I would think that would be a 50mph plus boat with the motor running WOT. Heck I have only ran aluminum props too. Right now I have a 4 blade 17p turning point ( nice prop, never blows out on turns ) I keep on for skiing and tubing this time of year. Boat holds 10 people. I get about 42 with 2 of us in it and fishing gear but I have to back off as it hits the rev limiter ( around 6200 ).

[staylor]

You’ve got a lot of options. One is to find a decent prop shop and take Tom P’s advice and have some cup added to the Black Diamond aluminum. Make sure you tell the prop shop to add some tip cup in addition to added cup on the back face of the blades. Cupping on the back of the blades adds a little pitch to the prop and helps it to hold better on turns. The added tip cup will get the bow of the boat up better without excessive trim. The second option is to have the Vengeance into the prop shop and have it knocked down to 17 pitch along with at least the added tip cup- I can’t tell you if you need more cupping on the back of the blades of a Vengeance without looking at the prop, but the prop shop can tell this easily.

If this was my rig, I’d try running a 17 Tempest 3 blade- and these are fairly easy to find used/on-line. This prop has a high rake blade to lift the bow and should run well right out of the box. The downside is that you may pick up some blade knock with the 150 4S at idle speed in gear which may be cured with a different hub kit from Merc. I had this issue with a 21 pitch Tempest on my 150 4S on a 17 ft Starcraft, but it may not be an issue with a lower pitch. I’ve found that the sweet spot on the 150 4S is to prop right up to 5600-5700 rpm with a light load.

The Nemesis is a decent aluminum prop, but I suspect it will not have the top end of the Vengeance. The Merc Rev 4 is more of a big boat prop so I don’t think it would have the top end of the Vengeance. The 4 blade Trophy Plus is a small hub prop and vents around its hub on the 150 4S. I like the Trophy Plus and currently run a 23 pitch modified to a 24 pitch on my very lightly rigged Starcraft with 150 4S- but with the small hub I think it would give you excessive venting on your rig- and pulling a tube is probably impossible.

Life was a lot easier when most props looked the same, had 3 blades, and you had a choice of aluminum or SS only. I’m from the “Bronze Age”- when I started boating in the 1950s the choices were aluminum or bronze only, and 2 blade props were quicker than 3 blades....
Doug