Newb drags 74 CrestLiner Nordic 17' 135hp from MI to FL. Could use a new prop.

[BananasCentral]

Before this I'd only had trolling motors or a 5hp, always on flatbottoms.
I wanted something aluminum for taking to the Gulf spearfishing and did some CL boat shopping while on vacation last month.

No one around Central FL has ever seen one of these, pictured with a 2010 CRV that pulled it home. (I pull with a F150 around here)
<a href="http://photobucket.com/" target="_blank"><img src="http://i295.photobucket.com/albums/mm143/Gratewhitehuntr/20160903_1449061_zps611ed577.jpg" border="0" alt=" photo 20160903_1449061_zps611ed577.jpg"/></a>

We rode it around Lake Superior, this pic was taken after running round Mackinac Island, this is a lighthouse in St. Ignace.
<a href="http://photobucket.com/" target="_blank"><img src="http://i295.photobucket.com/albums/mm143/Gratewhitehuntr/SAM_9458_zpse077a648.jpg" border="0" alt=" photo SAM_9458_zpse077a648.jpg"/></a>

I got a good enough deal to do some work on it. MI vs FL boat prices are night and day!

Here is the easiest possible way to remove foam from a boat. 13hp 4000PSI pressure washer with turbo tip WATCH YOUR TOES!
<iframe width="560" height="315" src="https://www.youtube.com/embed/n1fZfjC7Quk" frameborder="0" allowfullscreen></iframe>


EDIT maybe the wrong section for restoration talk.

Where I could use some help is prop selection.

This is a 1976 Johnson 135hp
The trim pin is one hole from the bottom, bottom hole puts the bow down and sheds 2-3mph, 3rd hole goes lightly faster but is kinda rough and likes to lose grip.
I've moved load around and it hardly seems to matter.

Right now I'm running a SST of unknown pitch, max rpm 5200, max mph 36-37 as indicated by installed gauges.
Max mph is basically the same with one man or loaded close to capacity (1350lbs people)
Cruising I get 4000rpm = 20-22mph. 3000rpm =18-ish but feels like I'm lugging.

It does slip when turning.
It does have a hydrofoil.
It JUMPS to plane much faster than a bass boat we talked with yesterday.

I'd mostly like to cruise around 3000-4000 rpm or 20-ish mph and get better mileage, will frequently be loaded with XX fuel.

Dunno if I can hotlink or embed yet, it doesn't seem to be working, if nothing else it'd be nice to publish some pics of this grand ol tinny!
Thanks in advance!


DOH! edit
I was looking at Solas HR Titan #2453-130-17 Stainless Steel Boat Propellerhere at Iboats as possible replacement.
The SST prices are so low I won't bother getting it fixed, just keep as a spare/beater.

I've set $300 as the arbitrary limit for a prop, lots of props in that range and I'm not racing.

 

[BananasCentral]

Ok I can get pics to post!!! (though not in the proper order)



Now back to props!
I learned how to measure prop pitch, will get on it in the morning soon as the skeeters abate.

Sorry for sounding slightly scattered, I'm still excited at having a REAL boat.

 

[BananasCentral]

Prop, transom, and cav plate pics.

I'm using the pin to hold a trim setting, it works for tilt, but won't hold position under power due to leak down.



I'll be on the lake tomorrow and check the water/cav plate height while on plane.

Right now it looks like I should raise the engine one hole. Does someone agree?
Some rivets, but no hook.



I'll have to drill a couple holes to raise the engine, they mounted it goofy.

If someone could point me towards the rebuild kit for this trim/tilt setup I'd be grateful, THE ENGINE # DOESN'T EXIST and that somewhat complicates locating the appropriate parts.
I'm sure some version of the 115hp setup will work, I just haven't found it yet.





How would you rate this prop on a scale of 1-FUBAR ???


Hopefully this information is helpful. I'm trying to figure out how to get my speed to display on GPS, a Globalmap 3000.

Oh, prop slip calculator put me somewhere around 37%! This is based on guessing 19p for the prop (most common SST I see) and my butt speedo agreeing with the boat speedo, between the 2 I'd expect decent accuracy.
No matter what pitch I enter prop slip appears WAY high.

Sorry to reply to my own thread, it's been too long to edit my previous posts.
Thanks!

 

[jimmbo]

Your boat has a Keel that extends all the way to the transom. Because of that, you can't raise the engine like on a boat without the keel that far back. looking the pics your engine height is about right, or even a bit too high already, you say you have 37% slip
I'm surprised there is no deformation with the transom unsupported. The prop is showing signs of wear, with one of the blades still showing a sign of impact. It might have been rebuilt already
The engine had been mounted differently at one time. Perhaps on different boat. The lower holes used were there as an alt spot if there was interference on the normal location.
Your engine has power tilt, not power trim. It is not designed to hold the engine up at speeds much higher than idle. When it drops to the tilt pin when you give it gas, it is working as designed. The power trim for that engine has two rams outside the tilt bracket, bolted to the swivel housing

 

[BananasCentral]

OK thanks Jimmbo!
Both good and bad news.
I didn't want to raise the engine! But no power trim
That doesn't break my heart since it runs best in a narrow trim range that keeps the hull transition in the water, same position makes for a great holeshot.


What comes next?
I can't find a local shop who will swap props.
The prop shop says $50-$150, I could just get another SST for that kind of $$$. Maybe they'll even this up for $50?

3 blade 13x19? 13x17?
4 blade 13x17 ?
Do I have any options to increase rpm OTHER than reducing pitch?

Like I said, best ride speed is 20-25mph.
I like going fast on motorcycles but not boats.

If you wonder why I'm asking questions...... well I didn't know the difference between tilt and trim....... DOH!

 

[jimmbo]

Power trim was offered for your engine. Your speed, is that GPS, or water pressure gauge(speedometer)? Before prop recommendations can be made the current pitch needs to be known. The info should be on the hub, under the prop nut and washer

 

[BananasCentral]

I'm going fishing in the morning, will pull the nut after I get back.

Prices for power trim components are redonkulous. I'll be ok for now without it.
Besides that the prop loses grip trimmed out one hole further, not sure how much it'd help to have power trim.

Speed is by the installed speedo (on the transom, I don't know what kind it is) , which corresponds aprox with my brain's estimation. We have some narrow canals between lakes and it gives a good feeling for speed over ground.
I know they are inaccurate and will try to get the GPS to display speed tomorrow.

I guess what I'm saying is, the online speed estimators think this boat should go 44mph and internet posters say engine is supposed to run 5500- 5800rpm.
I'm at neither.

 

[jimmbo]

If the engine is in good shape, is in good tune, and propped correctly, 44 mph is not unreasonable. That assumes the hull is good too. The WOT rpm range is 4500 - 5500. Some people like to spit them faster, but the power drops off above 5400

 

[BananasCentral]

First I'd like to say thank you for replying Jimmbo.
Thank you for confirming 44mph to be within reason.

Second, I do have more mechanical experience than I'd like and I believe this engine to be both strong and in good tune.

I've blown up several lifetimes worth of landlubber motors already and don't care about WOT except to use it as a gauge for proper pitching.
This is a near shore spearfishing rig and bass on smallish lakes around here. Not too small, not too big, NOT TOO FAST!

Maybe soooooooomeday I'll buy a V-King.

EDIT
Could you be more detailed with "assuming the hull is good too" ?
I've seen the hooker and rocker talk, is there more?

 

[jimmbo]

Mainly the Hooks and Rockers. Weak transom is another issue. Twisted hull. If the hull had been patched it could affect it. A hook or Rocker doesn't need to be huge. an 1/8" over 4 ft is big.

BTW the gear ratio for your engine was 25:13, well the factory gearcase was that. the other V4s that year had 26:13. The difference will affect theoretical speed calculations. But a 17 inch prop with engine spinning 5400 and with 10% slip would be near the mid 40s.

 

[BananasCentral]

Adjusting for the 1.92 ratio you've stated changes things quite a bit.
I got 1.65 ratio from another forum (but they also stated 25/13, never trust someone else's math!)

After running a lot of 17p and 19p variables I've arrived at...... drumroll...... remove the doel fin and try again! DOH!
The speed difference between pitches and prop slip all falls within the margin of things possibly attributable to the hydrofoil. (and my having a eyeball reading of speed)

How do all the dimples from rivets effect hull "quality"?
What sort of "constant" should I enter here? http://www.go-fast.com/boat_speed_predictions.htm

Dang I hate being a newb, but I LOVES me some new stuff! LOL

 

[jimmbo]

Doel Fin? Belongs in a garbage can. If they provided any benefit, Evinrude, Mercury, Yamaha, etc, would be making the anti-ventilation plates that size in the first place. They place a huge strain on the tilt tube of the outboard. The rivet heads are actually the opposites of Dimples, think of them as hundreds of tiny Rockers . They may or may not affect performance. They rough up the water a bit and weaken the surface tension between water and the hull. Kind of like how the tinniest ripples on glasslike water help the boat go a tiny bit faster. I've seen some tin boats go pretty fast. They are general lighter than glass boats.
Your going to run it tomorrow, before you launch it, or after you load it, could you run a straight edge down bottom of the keel, I just want to see how it lines up with the anti-ventilation plate. Also your WOT rpms. You say you have run both 17 and 19 props? What brands were they? At least one is an OMC/BPR SS. Rpm numbers and mph numbers for both please. Observe if the engine seems to downshift gears in turns or upshifts upon acceleration from idle. It can't downshift or upshift, but when a prop loses its grip on the water or grabs onto the water, it will sound like a gear change. If it does, a prop with more rake and/or cup may help, or the engine is too high on the transom. You said the prop ventilates if you move the tilt pin out a hole. Lowering the engine would put the prop into solider water. It will also give more leverage to lift the bow, which will reduce wetted area and drag, but without power trim it is harder to achieve optimum engine trim all the time.

 

[BananasCentral]

Thanks for stayin' with me Cap'n Jim!

I've only run this prop, based on availability likely a OMC SST 13x19p , will confirm the part# today.
Anything else was a online calculator, MUCH less heartache than running round the internet with wallet in hand!

It will be a challenge to straight edge the keel past midway, the trailer features a roller DIRECTLY under the keel and the water here is black (and I'm not going in it).

Anything else will have to wait till I get the fin off today.

 

[BananasCentral]

Got the GPS to display ground speed.

trimming around for best speed.......
With fin 36mph 5200rpm ROFL!!!
Without fin 41mph 5500rpm.
Without fin 28mph 4000rpm.
Without fin 20mph 3000rpm.

Caught one bass on a beetle spin casting into maidencane in 4ft of water .
Florida changed the rules to allow anglers to keep bass of any size, only one fish over 16".

 

[jimmbo]

Looking at the picture, the last keel roller is in front of the axle, You only need about a foot and a half in from the transom establish the keel line. I just want to see where the antivent plate is in relation to the keel. as in even, higher, lower. Photos, errors in height, angle, lens tilt, focal length and even lighting can make a pic look deceiving

 

[jimmbo]

My calculations show 46.3 mph @ 5500 rpm allowing 10% slip or 43.6 @15 % slip. You said ground speed. Was there any current to the water? that adds another variable to the gps measurement.

 

[SkiDad]

That's a nice improvement!! Those numbers seem to indicate a 17p prop ?

 

[BananasCentral]

Removing the tail did help.

No current.
Forgot to mention that cav plate is at proper height when planed. Wet, but not dunked.

It goes fastest at the 3rd hole, 41mph, but the wind picked up today and it was pounding us mercilessly in some 2ft chop. No matter the speed, it rode rough on plane.
I stopped and adjusted the pin to the 2nd hole and we drove through it like butter.

The boat rides better when trimmed in to the second hole but maxes around 38mph.
When trimmed to the second hole I can still only get 5300.

I still didn't pull the prop nut LOL we went fishing twice today!
The bass were piling on the large white/red dot beetle spin, I think 1/4 oz.
I hooked one large enough double my med/heavy 7ft rod and to straighten the hook and lost him in the weeds. He actually got some drag out, I have 50LB braid and the drag set to cut your fingers X(
When flippin the weed line around here you gotta turn em (or lose em) but the hook gave out.

EDIT
I'm trying to define the trim situation a little better.
This isn't my boat, but shows the same hull very nicely.
If there are any waves that bow must be close to the water or it'll ride like a rowboat wearing a 30hp. Boom Boom Boom!
If the bow is held down you can hardly feel the waves, though there is a LOT more spray to the sides!

3rd trim hole puts the entry point on the 2nd roller
2nd trim hole put the entry point on the 1st roller
ride difference is night and day


Notice that is also a Northern boat!
That spray rail works very well.

 

[jimmbo]

Your rpm will go up as the boat moves faster. On my I/O there is about a 700 rpm change from fully trimmed in to fully trimmed out at WOT. Boat speed changes greatly too.

 

[SkiDad]

I would just do 2nd hole. That's about where I set my trim too for the best ride.