stimleck

Hello
I am seeing about 25% slip right now and was curious about which items to check first.
I am getting bottom paint stripped over the winter and possibly epoxy painted (depending on condition of the gel)

AllDodge

How's the coupler?

dsmawd350

Props and x dimension.

Boat power prop etc?

stimleck

Boat is a 1996 Wellcraft Eclipse 260s Dry weight advertised as 4500 lbs

1.50 bravo 1 drive (straight)
The drive does hang low, in fact the nose of it does not even trim up enough to clear the bottom of the boat in trailer mode. I have no idea how to determine X dimension

Motor is a Gen V 1996 carbureted 502 mag reman with (now) 20 hours on it, purchased as a complete with stock manifolds. MSD ignition, distributor, and coil (all marine grade) (original motor was a 454/330 that I only drove twice with a broken speedometer and no gps. I am pretty sure the built in rev limiter of my ignition is 6000 and I know for sure I haven't hit any rev limiter yet.

The Hull is a 21 degree and likely has a hook because its not a speed boat
Has about 4 layers bottom paint, partially covered with tremclad rolled on by the idiot ex owner that didnt like the green bottom paint. Can bottom paint have a significant impact?

I believe the coupler is fine based on an inspection prior to installing the motor but to be honest I'm not skilled enough to determine that.

Speed is measured by GPS, RPM is measured by an inexpensive Faria tach

Original prop was a 19 mirage-It would cavitate under hard acceleration and hard turns and over rev the motor
I tried an Enertia 22 pitch 13.5 diameter and hit 50 @ 4750 rpm-all pvs holes plugged
I tried an Enertia 21 pitch 13.5 diameter and hit 50 @ 5000 rpm-all pvs holes plugged
(these are listed as bravo 1 compatible, Eco is the outboard version)
I tried a 21 High Five with no pvs plugs and it blew out at 2500 rpm
I tried a 19 pitch 4 blade bravo knock off (I think its a 15" diameter) that had slightly better low end and better lift but hit a rock before I topped it out.

Based on my inquiries with other owners and seeing for sale ads the factory top speed was low 40's with a small block and high 40's with the 454/330. I assumed I would see 55-60 with the 502
Here is a spec sheet and a photo of the same boat from behind
Thank you in advance

[ATTACH=CONFIG]531120[/ATTACH][ATTACH=CONFIG]531121[/ATTACH]

AllDodge

Is the speed your reading from the one on the boat or a GPS? Boat speed-o's are not very accurate. If your using the tach on the boat this also can be suspect. You have a single prop, Bravo 1 and the diameter of the prop is probably 15.25 diameter

stimleck

Speed is from GPS but rpm is from faria guage
it is a bravo boat but the diameter of the prop is 13.5. I was looking for a bravo prop but they don't make them small enough.
I tried a mirage and it wouldn't hold in corners, I don't recall the diameter of the 4 blade

AllDodge

You know you might have an issue with your engine. I have a 4500 pound Rinker with a 330hp 454. My drive is a 1.50 ratio and I turn a 21 pitch by 14 3/4 diameter, engine turning 4800 rpm (between 58 and 60 mph). Prop slips is 5 to 9 percent using bblades calculator. Your turning a prop which as a smaller diameter and less pitch and still hitting only 5000 rpm. I would suggest doing a compression and leak down test.

http://bblades.com/propeller-slip-calculator/

Cole2534

Your bravo Rinker gets the same slip numbers as a Skater with #6's?

Black Baja

Ahhh did you ever think about trying an inboard rather than outboard prop? Just a thought.

AllDodge

Not knowing what the OP drive ratio is and entering 1.5 as a guess, I think he is not that bad so far as slip. What gets me and the reason for my prior post, is his engine should have about 100 more hp then my Rinker, yet he turns a smaller prop and cannot turn it more then 5000. I have a 19 pitch prop and only use it when I plan to have a fully loaded boat out for an outing. I'll over rev with the 19 when it's just 4 folks